Furnace Troubleshooting (the first step)

November 24, 2006 by Chris
Filed under: Service Issues

I recently had a furnace come in- complaint was that nothing happened- no fan, no heat.. nothing.

Whenever I have a furnace problem, the first step I take is to go to the thermostat. This one had a simple heat only, mechanical thermostat. I pull the cover off, switch my multimeter leads to read amperage and hook up the leads across the thermostat terminals.

On this furnace, I immediately read a 1 – 1.4 amp draw, which dropped quickly to around .2 amps. This told me the time delay fan relay in the furnace was good (on [b]most[/b] furnaces built in the past 20 years, this will be a valid test- the exceptions will be new models with “fan control” circuit boards, or models where the board has been retrfitted with a Dinosaur brand fan control board).

After about 40 seconds, the blower came on, and the amperage rose a bit to around .5 amps. After another 45 seconds, the amperage rose again to about 1 amp.

What these readings told me was 1- the relay was good and the furnace had power (the initial high amperage reading was the heating element in the relay heating up), the second amperage jump (after the blower came up to speed) told me that the limit switch and sail switch were both OK, and power was getting through to the circuit board, the last amperage jump told me that the gas valve was getting power, and the circuit board was opening it. (A side point is that the final amperage reading- 1 amp- is the setting that the “anticipator” should be set at on mechanical thermostats).

For that job, I was lucky- the only problem was a bad connection in the thermostat- I repaired that connection and the furnace worked fine, but I hope you can use this method of troubleshooting to diagnose furnace problems (if you have a combination heat and AC thermostat, the same method can be used, but you have to find and break the correct thermostat wire to the furnace, which is usually easiest to find right at the furnace, and will nearly always be one of the two blue wires).

–Chris

Tags: amperage, furnace, Hydroflame, relay, RV, Suburban, thermostat

Comments

250 Comments on Furnace Troubleshooting (the first step)

Charles on Mon, 5th Feb 2007 3:29 am

Was having problem with no air forced coming through ducts
in bedroom. Removed furnace to clean and check for duct blockage.
Found medal tape had fallen off and was restriction flow. Fixed that
problem, cleaned fan and reinstalled furnace. Hooked everything back
up except the thermostat wired. Learned long ago to jump the wires out at
the furnace and check it before closing the compartment. Worked fine. Finished
hooking everything up and closed compartment. Turned on thermostat and NOTHING
worked. No heat, a/c or fan. Pulled the thermostat, took off the furnace
thermostat wired and hooked them together. Furnace worked. Haven’t finished trouble
shootong the thermostat yet. Long process for a solid state thermostat with a/c,
fan and furnace all on one thermostat. Even with furnace wires disconnected,a/c
and fan will not work. Seems 12 vdc comes through furnace. Any sugestions? What
little troubleshooting I have done, nothing makes sense. HELP!!!

Anonymous Reply:
November 15th, 2008 at 8:37 am

CHANGE TSTATE

Anthony Estres Reply:
November 25th, 2009 at 1:57 pm

I have a furnance that seeto work well,but it only gives off luke warm heat. Please helpe.

Chris on Mon, 5th Feb 2007 10:00 am

Hi Charles- the first thing I would look at is which wire hooked to which from the furnace to the thermostat.
One thermostat wire out of the furnace will be “hot” (+12v), and if it is not hooked to the correct thermostat lead, the thermostat will not have 12 volt power to operate.

Jean on Sat, 24th Mar 2007 10:02 pm

I use a heat pump/propane furnace. In this weather the heat pump always works but when it is colder the propane comes on and a blue light on my colemane revcon thermostat comes on. Lately a red light has been coming on. It says emg above it. It stays on and circulates the air to keep temp stable but is just blowing air. no heat. Any ideas?

Mike Reply:
February 15th, 2009 at 2:13 pm

@Jean, The emg stands for emergency heat which are heat strips built in to the air handler for extra heat. You might not have these strips and are just blowing the fan without any heat. A true heat pump doesn’t need propane but should heat with a reversing valve near the compressor. A tech needs to reconfigure your thermostat for what you have. If you have a true heat pump the supply air will be arouind 105-110 degree in heating mode, LP will be hotter,125ish.

Chris on Mon, 9th Apr 2007 3:09 pm

Hi Jean,
I hate to say it, but I am unfamiliar with that type of thermostat in an RV, and cannot find any information about it on the Coleman website (or in my service documents).

– Chris

BOB on Sun, 9th Sep 2007 7:18 pm

HI CRIS,
I HAVE A Coleman THERMOSTAT WITH A 2 AMP FUSE THAT BLOWS ABOUT IN ABOUT 5TO 10SECONDS AFTER THE FURNACE FAN 12 VOLT MOTOR STARTS.IT IS NOT CONNECTED DIRECTLY TO THE BATTERY. THIS THERMOSTAT ALSO WORKS THE AC WHICH WORKS FINE.ANY IDEAS AS TO WHATS BLOWING THE FUSE?? THIS IN AN RV. THE FURNACE IS A EXCALIBUR 8500
BOB

bob on Fri, 19th Oct 2007 12:38 pm

My father-in-law has a 37′5th wheel forgot the model? but it has a sububan lp furnace.We had it going and worked well but after we brought it to his lot now the pilot would not stay lit.After some investigating found a bees nest in the exhaust.We pulled it out with a bent clothes hanger then blew it out with air.Now it wont stay lit at all

J on Sun, 11th Nov 2007 6:34 pm

Hello,
My propane furnace will not keep the pilot light lit after it is finished running. It will make a click sound and the pilot will go out. I just changed the thermocouple two days ago and it did not solve the problem. Any insight will be greatly appreciated. Thanks,
Jeffrey

Anonymous Reply:
December 1st, 2009 at 12:58 pm

My propane furnace will not keep the pilot light lit after it is finished running. It will make a click sound and the pilot will go out. I just changed the thermocouple two days ago and it did not solve the problem. Any insight will be greatly appreciated. Thanks your words my problem~ what fixed it?

Chris on Wed, 14th Nov 2007 5:35 pm

Hi Jeffrey,
A couple of things to check- the pilot assembly may need to be cleaned, and sometimes if the pilot is set too high, it will starve for oxygen just after the burner shuts off, and go out. The flame should *just* envelope the end of the thermocouple.
But.. in some furnaces it is near impossible to actually see the pilot flame.

– Chris

TERESA CANNON Reply:
December 6th, 2009 at 11:20 am

MY PILOT LIGHT GOES OUT AFTER IT RUNS THROUGH CYCLE

Joe Pazzelli on Thu, 15th Nov 2007 2:03 pm

I’ve got an old Coleman 4225A furnace in a 1976 Winnie. Was running great until this fall(deer season). It is burning very rich, soot coming out of exhaust and too hot in heat exchanger. Pulled unit to check for any blockage or obstructions. None found. Both fans working well, just replaced the motor two years ago. Can’t adjust for a good blue flame as before. Very tall flame too tall, which starts out blue but too much yellow. Could it be an air leak or has the General Control 4225A809 gas valve gone bad? Gas stove and frig work okay, which I think leaves out main gas regulator.

Chris on Thu, 15th Nov 2007 7:35 pm

Hi Joe,
Generally that is sign of either too much fuel or too little air. Did it run OK after the motor change? If the motor was running backwards, it would still work, but not put enough airflow through. Likewise the combustion blower wheel could be installed wrong.
If I recall correctly, that unit has a cast iron burner- the slots in those burners are very prone to blockage by rust, which blocks the air flow as well.

–Chris

Joe Pazzelli on Fri, 16th Nov 2007 1:24 pm

Thanks Chris.
The unit ran fine after the motor change out, good clean blue normal size flame on all three burner sections. It does have a cast iron burner. I’ll check for blockage there. The only other thing is can I still get a gas control valve for this unit or will I have to replace the furnace?

Chris on Sat, 17th Nov 2007 7:41 pm

Hi Joe,
I really don’t think the gas valve is the problem- I would bet on the slots in the burner being plugged up.
It’s been a while since I services one of these, but I *think* that the slots are wide enough that they can be cleaned with a hack saw blade- you don’t want to make the larger, just clean them out.

– Chris

Joe Pazzelli on Mon, 19th Nov 2007 7:33 am

Thanks Chris,
You were right on the slots being clogged. I remember cleaning them out when I replaced the motor. Unfortunately when I put the unit back together, the pilot won’t stay lit so I’m getting a new thermocouple today; hoping to fix all my problems. As for the valve, I was told that they are no longer available. I just wanted to know if I could still get one.

margaret on Thu, 29th Nov 2007 9:31 am

I HAVE A WALL FURNACE AND A MECHANICAL THEMOSTAT. I CAN’T GET MY THEMOSTAT
TO COME ON. I CAN GET THE WALL FURNACE ON BY JUMPING IT. I CONNECTED A HOT
WIRE TO ONE OF THE PLACES WHERE I JUMP IT AT AND WHEN I DO THIS THE THEMOSTAT
WON’T TURN OFF. I HAVE TO GO BACK TO MY WALL FURNACE AND DISCONNECT THE
HOT WIRE FROM WHERE I JUMP IT AT TO TURN IT ON. MY THEMOSTAT IS A MECHANICAL
ONE WITH MERCURY. CAN YOU HELP ME OUT WITH THIS PROBLEM. I NEED TO BE ABLE
TO TURN MY THEMOSTAT OFF AND ON WHEN I WANT TO AND IF WANTED TO LEAVE IT
ON THEN I COULD ALSO AND NOT WORRY ABOUT IT. I JUST WANT IT TO WORK RIGHT.
ANY SUGGESTIONS WOULD BE GREATLY APPRECIATED VERY MUCH.

THANK YOU VERY MUCH. I WAIT TO HEAR FROM YOU.

SINCERELY,

MARGARET,
mchwalowski@yahoo.com

Chris on Fri, 30th Nov 2007 8:01 pm

Hi Margaret,
I guess the easiest thing would be to replace the thermostat, but you might take the cover off and look for a small adjustment called an anticipator- which will be a wire with a slide connector on it. Sometimes they are a round assembly, sometimes they are straight. If you move the slider down to zero, often that will “fix” a problem like that (the wire sometimes gets corroded, and moving the adjustment can help.
To replace it, a popular replacement is the Hunter model 42995, which is available at WalMart for about $20. It is an electronic model, but will work fine for furnace only- just hook the 2 wires to the RH and W terminals.

–Chris

Sherii on Mon, 3rd Dec 2007 8:38 pm

Hello, I have an Excalibur Hydroflame 8500 IV which seems to have lost it’s muscle. Everything works fine as it always has – with the exception that it doesn’t seem to heat my bus up like it used to without consuming excessive amounts of propane. I think that the flame must not be hot enough anymore but I can’t see it from any angle inside or out, I can however hear the difference if that makes sense? Every winter (this is the 5th) I acclimate to the familiar “tiger torch roar” but it is a sub-sound under the blower motor this year. Plus the air just doesn’t feel as hot as it used to coming out. From my RV repair books I think the burner/flame has issues but they don’t show how to get at the burner of this model, nor does the 3 page Atwood installation manual. Is there an easy way to determine if this is the problem? I live in the bus so leaving it at a shop is out of the question – and pulling the furnace out would have to happen while it’s snowing because it won’t be warming up here again until May… Thank you for any suggestions or directions on how to see or clean or adjust my Hydroflames Flames!

James on Thu, 6th Dec 2007 1:12 pm

Hi, I have a Coleman [High efficiency gas-fired furnaces tubular heat exchanger series Model: P*UR / G9T-UP/ FG9-up (upflow) 40 - 140 MBH input] and it seems that our furnace turns on, but shuts off after 1 or 2 minutes of heating. it seems to give 6 red flashes when i check the furnace control dignostics, and in the manual it seems that 6 red flashes mean, the pressure switch opened 4 times during the call for heat?? and we have no idea what they mean by delay on or off mode. can you help me with this problem?

Sincerely James

Michael on Tue, 11th Dec 2007 4:04 pm

I have an older Lennox forced-air furnace with a standing pilot. For days the pilot would randomly go out. I replaced the thermocouple, cleaned the orifice, and ajusted the small hood on the pilot flame opening.
The thermocouple it sitting nicely in a strong blue flame, and once the pilot is lit it will stay lit for five or so minutes and then you can hear the solenoid release the gas valve and it closes. End of pilot.
Any idea what this problem might be? When the furnace runs, it runs well. The gas valve just won’t stay open to keep the pilot going. I hope it’s not the gas valve.

Thanks!

Regards,

Michael

Chris on Tue, 11th Dec 2007 4:17 pm

Hi James,
I’m afraid I don’t have any service information (or, for that matter, any experience ) with home type furnaces.

But.. Michael- I would almost be tempted to replace the thermocouple again, as I have seen brand new thermocouples fail. They wrok using two different metals, which generate current when heated, but every now and then the junction between these metals can open up when heated.

– Chris

Michael on Tue, 11th Dec 2007 4:57 pm

Thanks Chris. I’ll try that. Ggrrr.

Chris on Tue, 11th Dec 2007 6:15 pm

Hi Michael,
One more thought- the connection of the thermocouple at the valve is actually an electrical connection- if you look at the end, the very tip is insulated from the outside of the tube by a thin insulator.
The thermocouple should be hand tightened firmly, plus a quarter turn- if the pilot doesn’t stay lit, give it another quarter turn. Over tightening can crush the small insulator.

– Chris

Ron Bennington on Mon, 17th Dec 2007 3:39 pm

Hey Chris,
Just bought a used RV, suburbane furnace. have got it to light off twice in two weeks of trying every day, 6-7 times a day. Removed furnace, removed board took it to RV repair shop, board tested ok. I get fan, I get spark, just not lighting the pilot.

Kenny on Sun, 30th Dec 2007 5:22 pm

I have a Suburban SF-30 in an Outback 33′ that is 1.5 years old and on it’s second cool season. It always seemed to a little temperamental when igniting but has generally been trouble free. Today, not so. Everything starts and runs but no ignition takes place. Coincidentally, I had a tank switchover take place about the same time it quit. The switchover appeared to be normal as I have gas at the stove, frig, and hot water heater. I broke the line at the heater and have it there as well. Both tanks share a common regulator on the output of the switch. As for correct pressure, I don’t have a manometer but judging from the stove burners, it looks okay. ( Side question, just how much of a pressure drop can a furnace stand before it refuses to work??) Could the switchover have starved the furnace and damaged a gas valve or something? Because of it’s location, it appears that it has to be completely removed to service the components so I don’t want to do that unless absolutely necessary. Any input to a possible solution would be appreciated. Thanks.

rick on Wed, 2nd Jan 2008 11:59 pm

I have the exact situation as Kenny above blower blows plenty of propane, igniter tries three times but will not fire furnace. Please comment, ASAP I’m getting cold.
thanks,
rick

john on Thu, 3rd Jan 2008 9:50 pm

Well let’s make that 3 of us, I have 05 TT with a Suburban sf30f, stove work great, blower comes on then 3 or 4 popping sounds then the blower shuts off(this is in about 10 time span)…I going to wally world and buy a radiator heater

John Reply:
November 11th, 2009 at 6:57 pm

Sounds like Suburban should have recall on these!!! We have the same problem.

glen on Sun, 6th Jan 2008 10:55 pm

Make that four of us. I have a Suburban furnace that’s be working intermittently. Now it won’t work correctly. The fan comes on, I hear the igniter, smell the propane, but no ignition.

FurnaceGirl on Mon, 7th Jan 2008 3:23 am

For the guys up above:

Unlikely this could help all of you but may be of help so I offer it up – I had a similar problem with my furnace last year that was due to an overfilled propane tank. Electronic lockout can occur if the gas pressure coming is too high, it’s a built in safety feature. Another similar situation my first year way back was flies and spiders camping on the burner – they clog the combustion process – after I got it lit a dozen times or so (each time it stayed on a few seconds longer) they were burnt off and I had no problems.

Good Luck!

glen on Mon, 7th Jan 2008 10:24 am

FurnaceGirl,
Thanks, but no bugs in the burner and I’ve tried with two different propane tanks – one about 1/5 full and the other full (well, “OPD” full).

Eric Reply:
January 24th, 2009 at 4:11 pm

Hopefully this will prove helpfull for some of you above.
I was repeatedly having a similar problem with my Hydroflame and by accident found that removing with a toothbrush, the dust bunnies and grime that seems to accumulate rather quickly on, in and around the circuit board, the blades of the “squirrell cage” fan and shroud (which also includes the sail switch, interior of furnace compartment and any air inlets to the furnace inside the RV, totaly fixed the problem and allowed me to gear up for the next thing to go awry in my aging RV. Sounds stupid, but apparently these things really need to breathe and grime build up on the fan blades seems to throw off the motors balance resulting in awful sounds while running, earlier demise of the motor and sub optimum performance.

~Eric

garry Reply:
July 21st, 2009 at 8:10 pm

the tank regulator should prevent pressure problems from the tank unless it has malfunctioned.

John on Tue, 8th Jan 2008 6:38 pm

I have a 8500-iv hydro flame seies furnace in my 2003 Toy hauler.I have trouble shot to the best of my knowledge,the blower works,electrode works,but no power from ignition board to valve.also after electrode stops trying, red light on ignition board comes on.Any help would be appreciated.
Thanks,
John

Roadless Warrior on Wed, 9th Jan 2008 3:05 pm

Sounds like your board may have died – common problem, not too hard to fix. Go here and search your model number for T-shooting and repair help.

Cheers (-:

benjamin gee on Thu, 17th Jan 2008 1:22 pm

i have a Suburban model NT-34L furnace. initial problem was a popping sound each time the burner lit. As i sleep with my head over the furnace, this got to be old in a hurry. I initially replaced the gasket around the burner access thinking that an air leak might cause the popping. still popped. I pulled the furnace, cleaned the blowers (intake and exhaust), removed the mud dauber nests, removed the burner and cleaned it as it 4 slots blocked with rust. reassembled furnace, reinstalled and guess what- furnace still pops upon ignition. It also will pop intermittantly if i let the furnace run. Gas flame is blue, some orange/yellow above the burner, flame kind of ripples right on the cast iron burner. no separation between flame and burner. Please advise and thank you.

Rich A on Sat, 16th Feb 2008 2:16 pm

Sounds like we may all have a similar problem. I have a Suburban N-30M furnace with the same problem as mentioned above. Solenoid energizes but propane is not flowing. I replaced the solenoid valve.. still not working. Tested ewverything on the bench and found that the solenoid although clicking when powered, is not allowing flow when energized under pressure. If solenoid is energized and then the propane is thurned on, I get flow. Confused as to why this is happening. I even tried botha 20psi and 10psi propane regulator. Any suggestions would be appreciated.

Rich A on Sat, 16th Feb 2008 3:54 pm

I found the answer to the post I made previously. The unit had been dropped off at my house by a friend who couldn’t fix it. I replaced the transformer and then ran into this “propane flow problem”. It seams he connected a supply line/regulator he had laying around to test the unit. This regulator was for 20 psi. Some research showed that the solenoid is only rated for 1.5 PSI. The hard piped line in the camper is regulated at this lower pressure and everything now works fine.

Jack on Wed, 27th Feb 2008 4:46 pm

Chris,
My furnace blower fan just stopped working today. I tried/tested the furnace a couple more times with the thermostat igniting the furnacw with natural gas burning fine—just no blower fan. is the problem most likely a fan motor gone out or could it be something else.

Chris on Wed, 27th Feb 2008 7:54 pm

Jack,
Is this furnace an RV furnace? The only reason I ask is that in new RV furnaces, the burner cannot ignite until the blower is running.
If it’s a house type furnace- I’m not that familiar with them, but usually the blower is controlled by a fan switch, which turns the blower on when the heat chamber reaches a set temperature.
If it’s an RV furnace, I would suspect the fan relay.

Bobby Simpson on Tue, 4th Mar 2008 11:00 am

I finally got the step working after another cleaning of the
large 4 way plug and the door switch. It seems to stay out now.
Thanks for the input.

mike on Tue, 4th Mar 2008 10:46 pm

I have a rudd furnece and it will be runing then it seems like a air pocket in the gass line and then theres 3 or 4 sucksons then the furnece shuts off then you here clicks then it starts back up right away and will stay runing and it will do this every now and then can you please help me thanks mike

Steve Rightnar on Sun, 16th Mar 2008 9:28 pm

Hello:
I have a Suburban SF-20F and nothing happens. No blower no clicking nothing and its just past the warantee. I checked that it is getting power and the power is there. The thermostat is putting out voltage when I switch it to the heat setting. I was going to bypass the control module and put the hot wire right to the blower but I dont want to try things without some advice. Thanks for any help!!!
Steve

Aldis crouch Reply:
December 27th, 2009 at 3:50 pm

Had same problem with new RV suburbian furnace, took it to dealer and it had air in the lines. Now I have same problem again. I have to find how to remove air from the lines

Steve P. on Thu, 3rd Apr 2008 12:14 am

I have a Suburban floor furnace in our 1992 Sandpiper. It has electronic ignition. When I turn the thermostat on the fan comes on and only blows cold air. I have been told this might be the thermostat but I do not know how to test it. Can anyone help. Thanks

Dale Randall on Thu, 3rd Apr 2008 5:38 pm

I wish that I would have found these posts before I tryed to fix my Suburban SF-30F furnace. The theromstat would start the fan, but there was no burner ignition. I removed the furnace. I took the burner apart and cleaned out the sand. I re-set the ignitor gap to 1/8 inch per the manual. After trying many different things, I jumpered the two blue thermostat wires instead of hooking up the thermostat. Then the furnace would start and light every time! Maybe a bad thermostat? I hooked up the thermostat again and found that the voltage to the limit switch was 7 to 8 VDC even when my converter was putting out 13.6 VDC, which is normal. I found a loose rivet in the Suburban thermostat, which I soldered (this can melt the plastic).
This fixed the problem, but I still couldn’t explain why the thermostat was only getting 11 VDC when the furnace was running (10 VDC at the limit switch. I found a two volt drop on the positive power wire to the furnace, but only 0.25 volt drop on the ground return wire. I replace the power two wires with about 10 feet of # 14 wire so the furnace now runs at full voltage.

FMB on Fri, 4th Apr 2008 11:54 pm

In my ‘04 Arctic Fox 24-5N, there resides a Suburban Furnace. It heats the
5th very well and will be 5 years old in July.

Since this is my first experience out of a tent or house, I thought my
furnace was working properly all along, till late last year. That is when
the steps in the furnace’s processes changed and made me think it may have
been busted from the get-go.

With the thermostat set at a temp higher than the room temp, I switch the
thermostat from ‘off’ to ‘heat’. Here are the steps the furnace took the
first 4 1/2 years;

1. Instantly, the blower motor comes on. You can feel the air blow out the
heater outlets in the floor.
2. It heats the trailer very well and when it reaches the thermostat temp,
the gas turns off and the blower continues to run.
3. The blower runs for about 2 min. (I understand this to be the ‘cooling
down’ time so the furnace doesn’t stop hot) At the end of this 2 min, the
blower power goes off and the blower begins to wind down.
4. Before the blower stops, it kicks back on and runs for another 2 min, at
the end of which, it powers down.
5. Before the blower stops, it kicks back on AGAIN and runs for another 2
min at the end of which, it powers down and stops.
6. The heater is off, waiting for the thermostat to tell it to turn on
again.

What changed to make me think this wasn’t normal?

Sometimes, the heater will skip steps 4 and 5, or will repeat step 4 several
times. The heater will cycle at least once, mostly 3 times, but up to 7
times (that I know of). The air is blowing room temperature after the 1st or
2nd cycle.

Relay???

Chris on Sat, 5th Apr 2008 8:08 am

Hi FMB-
I would guess that the furnace has been cycling on the limit switch- the thermostat is still calling for heat, but the furnace is getting to hot, shutting off and then cooling down and reigniting.
This is usually caused by not enough ductwork or a disconnected duct pulling hot air back in to the intake.
Given that yours has changed, I would guess that it was not enough ducts, and one may have split open- or you had a register that was closed that is now open.

Sorry about that- I went and reread your post- it does sound like the relay- I’m assuming that you don’t have one of the newer models with the fan relay on the circuit board.

Steve P- if you have a heat only thermostat , which only works the furnace, you can just take the wires off the thermostat and hook them together- the thermostat is simply an on/off switch.

–Chris

FMB on Thu, 10th Apr 2008 12:29 am

Chris, thanks for the reply. It is a SF30F and I don’t see a relay in the Installation instruction manual diagrams so I’m thinking it might be integral to the circuit board. I will have to pull the furnace out to determin that.

Oh, wow. Am I glad you only struck through and didn’t delete your first comments. I always thought the bathroom floor vent didn’t blow much and the bedroom vent blew less (barely felt air move). I took the cover off to measure voltage on either side of the Hot limit switch and it dawned on me the amount of air blowing with the front cover off was enormous. With the cover off heater on, the blower sends copious amounts of heated air into the room through where the cover and cabinet intake vent would have been. When it came time to turn off, it went through a ~2 min cycle and turned off. I repeated this several times. With the covers on, it cycled 3-5 times. Hmmmm…. plugged vent tubing somewhere I’m guessing now, cause when I remove the vents out of the system, the heater works fine. Back to looking at vent tubing tomorrow. Thanks.

Mike on Wed, 23rd Apr 2008 10:47 am

I have a Suburban furnace in a ‘87 Winnebago.
It worked fine until the day I needed it and then
nothing. Any suggestions where to look first?

Jami on Wed, 7th May 2008 10:42 pm

I need some help! I have an Atwood Mobile Products Furnace in an 04 Bayhauler Trailer. (Mod # 8520-IV-DCLP) The wall Thermostat control is a Duo-Therm by Dometic. The furnace kicks on, ignites and blows hot air, unfortunately it si for a very short peroid of time. The heater will blow for a few minutes and shut off. The camper never gets warm. The heater has worked fine and now all of the sudden isn’t working right. He have taken the inside and outside cover off and blown air around to see if it could be dirty. Any suggestions?
Thanks- if you can help it would be great it sure is cold in Wyoming!

Rod Wesling on Fri, 9th May 2008 2:58 pm

I have 86 winnie motorhome with Atwood 7912 Hydro Flame,blower(fan)runs continuously when thermostat is turn, on but no ignition(flame),gas is on,would you give me a step by step run down so I can find and correct the problem? Thanks Rod.

Doug H on Tue, 20th May 2008 8:32 pm

Chris: Have a Suburban SF-35F furnace in an 05 Hornet Retreat. Has worked fine for the last 3 years until last weekend. Turned furnace to Heat and instead of the blower coming on and running for 30 seconds to 1 minute before igniting all we got was a buzzing noise coming from the furnace. Turned furnace off and buzzing noise remained until approximately 1-2 minutes before buzzing noise turned off…almost like a blower cycle time. Waited about 30 minutes, turned back on, same buzzing noise occurred. Pulled furnace out, and with switch in heat mode buzzing noise occurred and noticed blower fan moving very slowly. Tried it the next weekend to see if there was any difference, furnace did nothing, no buzzing, no blower, nothing. Any ideas?

Eric Reply:
January 25th, 2009 at 1:42 am

I just had some dealings with a similar situation. Inside the motor housing is a magnet / coil assembly with brushes, like the inside of a power drill but bigger. Over time and especially in wet weather, dust from the rotation friction accumulates inside the motor housing and clogs up the motor. With a bit of patience and a little forethought, the motors’ housing can be removed and the interior cleaned with a dry toothbrush and the assembly put back together. The insides are magnetized and will offer some resistance but they will come apart.
It is imperative that the motors cap NOT be removed from the coil shaft as the brushes are mounted to the underside of the cap and are tight to the shaft. if the cap and shaft part ways then good luck getting them back together without breaking the brushes. GOOD LUCK.

Chris on Wed, 21st May 2008 2:02 pm

Hi Doug,
It sounds like either the blower motor or the fan relay. I would hook 12 volt power directly to the blower motor to see if it will run OK (make sure the blower will turn freely, as well).
If the furnace has the outside door, you should be able to do this without pulling the furnace out (IIRC).

Doug H on Wed, 21st May 2008 5:40 pm

Follow-up: Is the relay inside the furnace by the blower motor? No access door from the outside. Will there be 2 wires on the blower motor that I can hook 12v to, and is the white wire the ground on the furnace also?

nicole on Fri, 23rd May 2008 10:10 pm

i have a wall furnace(no idea what the make is) and it is controlled by a wall thermostat. it started to make a popping sound and than a ball of fire would come out from the grill. turned it off and cleaned it up, called the gas co and they said to let the dust burn. turned it on after it had burned clean and it popped and fire came through again. we have been using it for the past 7 years and never had this occur before. any idea what it could be? thanks

Doug S. on Sun, 1st Jun 2008 10:12 pm

Chris,

I have a Suburban furnace in my 01 Sierra. I have had an ongoing issue with the furnace that is frustrating me big time.

With fully charged batteries my furnace will run 2/3 through the night before it stops igniting and the fan runs cold. Last year my converter went on the fritz and I figured it wasn’t charging the batteries good enough. This year I installed a PD power distro center with the charge wizard. I still get the same result from my furnace. If I plug my truck into the trailer the furnace will run all night but if it runs off my batteries alone it will stop 2/3 through the night. I have two deep cycle batteries that load test really well and through all this the lights in my trailer never go dim so batteries are not on my list.

What is going on??

I replaced the blower motor

Doug S. on Sun, 1st Jun 2008 10:15 pm

Continued:

I replaced the motor in my furnace, it was dirty and the bearings were rough. I figured this was my issue but it is not.

Chris on Mon, 2nd Jun 2008 8:33 am

Hi Doug,
I would bet that there is a voltage drop somewhere in the system- probably several, so even when the batteries are still up, the voltage to the circuit board gets low enough that it will not operate correctly.
*If* the wall thermostat only works the furnace (and not the rooftop air conditioner), I would start there, but I’ve seen a lot of limit switches (which you access by removing the inside cover) with enough oxidation to severly drop the voltage- as well as the sail switch.

Doug S. on Mon, 2nd Jun 2008 8:54 pm

My thermostat does control the rooftop A/C and the furnace. So I start by inspecting the limit switch(inside the furnace) and then the sail switch. What would the normal voltage drop across these components be?

Is it safe to say seeing how the system works with the truck hooked up that the circuit board is OK?

Doug S. on Mon, 2nd Jun 2008 8:58 pm

My thermostat does control the rooftop A/C as well. I guess I will test the sail switch and the limit switch for voltage drops, what would you say is maximum acceptable across both these components?

Is it safe to say my circuit board is operational with no issues or may I have an issue there?

Anonymous on Thu, 24th Jul 2008 12:35 pm

i have a lennox system that the blower motor is staying on i chesck the limit swiths for conunity they r all fine i think it is the circuit board what do u think

kathie cooper on Thu, 31st Jul 2008 7:03 pm

i have an bryant gas furnace it was working fine on a summer eve.i had the a.c. on with the thermostat set on auto. I switched it to off,and also switched it to fan but the fan would not work. I tride a.c. with fan an d with auto. i also tride heat with fan and with auto. a.c unit out side turned on but no forced air.furnace turnd on but no forced air wat is the problem.

Christine on Wed, 20th Aug 2008 1:59 pm

Having problem with my Duo therm Dometic Unit The ac will not cut off by itself when it reaches a certain degree you have to cut it off by the hi lo switch. It will not cut off with the Heat off Cool switch. I have replaced the thermostat, control board, and a compaster on top. Have checked wires need help I don’t know what else to check. please email me. Thanks

Chris on Wed, 20th Aug 2008 5:10 pm

Hi Christine,
It sounds like you have replaced everything I would check, but it is very possible that you got a bad (or wrong) thermostat. Dometic has many different thermostat/control box versions.
Can you give any more information, like a part number for the circuit board or thermostat you installed?

Christine on Wed, 20th Aug 2008 5:37 pm

I’m at work right now but I get off at 8 tonight I took the old one with me and got the same kind . Thank you for writting me back. I can;t thank you enough. I will write you back as soon as I get home Also it is doing the same things the other thermostat was doing. How it has been working On the thermostat there is heat off cool hi lo on auto. It use to cut off when it got a certain temp like if it is set on 70 it would cut off but know it will not. the fan goes from high to low fan and the only way you can cut it off is by switching it to lo with the hi lo switch. It will not cut off with the heat and cool switch when you cut it to off it cuts the fan on low. It was working fine till one night I was alseep and heard a pop and got up and heard the fan on low and every since then it hasen’t worked right. Thank you for your help.

Christine on Wed, 20th Aug 2008 6:11 pm

Here aresome numbers I had wrotten down 3104757.004 control board 3104998 board and thermostat Relay kit serial #E6147786 for use with 579, 590, 595, 600 series Model 57915.421 Duo Therm Model 57915.421 product 991731645 Serial 61616390 Hopefully these will help.

Chad Reply:
April 20th, 2009 at 11:33 pm

Christine…Do you have your old part 3104757.004 Control Board. I cannot find one anywhere. Did you ever determine if it was defective, if not, would you be interested in selling it to me?

Chris on Thu, 21st Aug 2008 5:11 pm

Many apologies- I’m just not going to have time to research this right now, either here or on my RV.Net blog,as my shop and house are under water from TS Fay (and I only have about 1 hour of power per 6).
Arghh…. about 15-20 inches of rain in the past 8 hours, with more to come .

Christine on Fri, 22nd Aug 2008 1:03 pm

sorry to hear that hope things get better. I will keep you in my prayers.

Dwayne on Sun, 21st Sep 2008 7:03 pm

Hello Chris –
First: Hope your home is ok after the flooding!
Second: Thanks for a great resource & the personal responses for all here.

Here’s hoping I can contribute something for those of us with older RV’s.

Hunter 40020A mechanical thermostat sells for $10.20 at Lowes & is a generic replacement for the HEAT ONLY systems like my old camper’s Duo-Therm 65900 heat only furnace.

Manuals for many furnaces & RV appliances can be found at

Dwayne on Sun, 21st Sep 2008 7:05 pm

Manual link didn’t show up so here it is again:

http://www.bryantrv.com/owners.html

cameron on Sun, 21st Sep 2008 11:52 pm

I have a furnace not sure of the brand but sometimes it won`t ignite or it will after trying many times do you know what it could be?

cameron on Sun, 21st Sep 2008 11:53 pm

by the way its a rv furnace in a 1982 23ft prowler

Tom on Tue, 23rd Sep 2008 6:30 am

RV furnace will run 1 good cycle. On the second cycle,the blower comes on but no heat just cold air out the ducts. Need help please

larry on Tue, 30th Sep 2008 2:46 am

i live in a 1973 double wide mobile home. it has a Coleman cool and heat furnace we replaced the blower moter, everything seams to work good now but the the transformer makes a humming noise all the time. my question is, is it normal for the humming or is the transformer no good, etc.

Scott on Sun, 12th Oct 2008 10:04 pm

Hey Chris,
I have a Rockwood pop-up with a Suburban DD-17DSI, I need to replace the thermostat but don’t know what to set the anticipator to. What does the anticipator do? If set wrong what could happen?
-Scott

Chris on Mon, 13th Oct 2008 5:00 pm

Hi Scott,
The anticipator actually provides a very small amount of heat directly to the thermostat- so that the furnace will shut down just a bit before the set temperature is reached (because the furnace runs for a while blowing off residual heat) so that it will not get too hot.

That said- the anticipator should be set at .7 for Suburban furnaces (1.0 for Atwood/Hydroflame)- a common mistake is to set it too far down (to .2 or .3) which will burn it out from too much heat.

travis j. on Wed, 22nd Oct 2008 9:20 pm

I have a Suburban furnace in my travel trailer and when i turn it on, after about 20 seconds the fan turns on an blows cols air and nothing els happens, but it is getting fuel though.

Anonymous Reply:
March 21st, 2009 at 11:03 pm

if your batteries are not fully charged the ignitor will not work and you will need get lp to the furnace. try charging batteries or having them checked

Tommy on Fri, 7th Nov 2008 4:14 pm

I have a lennox propane furnace, it will light for a few seconds, then go out, re ignite, burn for a few seconds and go out….. have replaced regulator at tank did not fix, replaced line with new one, did not fix, what is left? Someone told me it sounded like water in propane tank. What does everyone think problem could be?

Thanks,
Tommy

Chris Reply:
November 9th, 2008 at 6:15 pm

Hi Tommy,
I’m afraid I don’t have any knowledge of home style furnaces, but it sounds like one of two problems- either fuel (which you have dealt with partially), or the flame sensing not working.
Home style furnaces use a lot of different methods to sense the flame, but I just don’t know about them.
Sorry…

garry Reply:
July 21st, 2009 at 6:19 pm

it more than likely is not water in tank. its very difficult to get water to gas valve unless you have open line and it rains or someone puts it in there,then connect s tank. could be vent problem.

Brenda Brooks on Thu, 13th Nov 2008 9:41 pm

Hi, I have a Suburban furnace in my camper. when i turn it on it runs great for a while then the blower starts turning off and on at 2-5 second intervals. Do u have any idea what could be wrong? its getting cold =(

Flip on Fri, 14th Nov 2008 7:04 pm

I have a Suburban furnace in my RV. It fires and runs fine until it hits the set temperature. It then will not relight. The blower goes, and it sparks, but no gas. Anyone seen this before?

Eric Reply:
January 25th, 2009 at 2:04 am

TRY RESETTING THE FURNACE BY TURNING IT OFF COMPLETELY AT THE THERMOSTAT AND TURNING THE TEMP ALL THE WAY DOWN, WAIT 5 MINUTES, TURN IT BACK ON AND TURN UP THE TEMP CONTROL (ON THERMOSTAT) UNTIL IT CLICKS, BINKS, BEEPS OR WHATEVER INDICATOR NOISE YOURS MAKES.

Chris M on Sat, 22nd Nov 2008 11:36 pm

I have a similar problem Flip. I also have a Suburban furnace in my 89 travelmaster that does the same thing. Usually only in the middle of the night when everyone is asleep. Lost of good info in this thread though. I’m going to go out and start checking voltages.

Hammer on Wed, 26th Nov 2008 7:23 pm

I have a 2006 cougar with a subarn furnace want come on with remote or by pushing heat butt no nothing what do i do

robert lequier on Thu, 27th Nov 2008 11:07 am

i have Coleman furnace ,when i light the pilot,it lights okay,but when i let up
the switch to turn it on the pilot goes out.. i have got it started a couple of times
the furnace has lit ,but after it cycled the pilot was off again

ty Reply:
December 2nd, 2008 at 10:02 pm

sounds like the thermocoupler

garry Reply:
July 21st, 2009 at 6:26 pm

thermocouple or clogged pilot orifice.

Ty on Tue, 2nd Dec 2008 10:14 pm

i have a Suburban sf35 in a 92 bounder. turn it on ,blower starts up,you can hear the igniter clicking………..no ignition. the clicker comes on several times. no ignition. plenty of propane in the system. took apart unit ,checked the orafice.looked good cleaned it anyway,replaced,no change…..-any ideas???????????????????

Anonymous on Wed, 3rd Dec 2008 2:09 am

WHY DOES A FURNACE IGNITER STAY LIT CONTINUOUSLY?

garry Reply:
July 21st, 2009 at 6:27 pm

in case of flame outage so gas would not escape into heat chamber

Anonymous on Wed, 3rd Dec 2008 2:12 am

OH! ALAN

Alan on Wed, 3rd Dec 2008 2:28 am

Sometimes soot can get into pipes and cause the furnace to go off and on without reaching the right temperture.

Don Mckernandoss on Fri, 12th Dec 2008 12:36 pm

Alan… I have DuoTherm ac with surban furnace. New thermostat… now the furnace won’t shut off until I disconnect all power.
I disconected the red wire at the thermostat but the furnace
just keeps on going.
I doublechecked the wiring at the thermostat and it’s correct to mfg spec.
Any ideas?
Thanks, Don

Chris Reply:
December 14th, 2008 at 8:30 am

Hi Don,
I’m assuming you have a DuoTherm Analog wall thermostat- with a slider to set the temperature. On that setup, the furnace is actually controlled by the circuit board in the ceiling assembly, and is hooked to the blue wires with a white stripe. At the thermostat, the white wire is the furnace lead.

Gordon on Sat, 13th Dec 2008 12:03 pm

I have a Suburban sf35f, year 2005
weird findings
will not fire at 13.6 volts
put a batt charger on at 12 v and it fires, drops to 10.8 v and runs fine
fires every time
Gord

Chris Reply:
December 14th, 2008 at 8:32 am

Hi Gordon- that is odd. I would be tempted to look at the grounding (I always look at the grounding!), but it could just be a bad circuit board.

Anonymous on Sat, 13th Dec 2008 9:40 pm

I have a 1977 Traveleze Trailer. It has a Duo Therm Furnace. The pilot lights, But when we turn on the blower the burners turns on, then a minute later the burners shut off and so does the pilot. What could be the problem

Chris Reply:
December 14th, 2008 at 8:34 am

Most of the time that’s a cleaning issue- the pilot is not burning correctly, and when the blower comes on, it pulls the pilot flame away from the thermocouple, so it then shuts down.
Because of the age of that furnace, it really needs to be pulled, inspected and cleaned to make sure the combustion chamber is solid, and all gaskets are good.

Sammy Andrews on Sun, 14th Dec 2008 12:08 pm

My friend called me and asked if I could help out with this problem. The only problem was is that I dont know how furnaces really work. He said that he can turn the heat on but it just blows air out not heat. What would be the first thing to check out frist? The theromstat,pressure switch or would there be another route you would take?

david on Sun, 14th Dec 2008 3:36 pm

my furnance just started acting up. theres a red light that flashes six times which tells me that the pressure switch has shut down. also ever since i ahve removed the face panel from the furnace it run great but when i replace the face panel. the furnance wont run properly…..what is going on?????

Chris Reply:
December 18th, 2008 at 2:29 pm

Hi David,
A couple of things come to mind- there is an air prover (a.k.a. sail switch) right inside the outer plastic blower housing. It sounds like this is either bad, or the return air is blocked somewhat, or the voltage is low and the motor isn’t turning quite fast enough.

Sammy Andrews on Sun, 14th Dec 2008 9:48 pm

I think its a duncan it had a ignition switch that said off and on. down where the burners where it was not getting anything. I took pictures. I also changed out the thermostat and it still did the same thing. i turned it on and the fan and blower came on but no heat. Please help.

Cold in Nevada on Wed, 17th Dec 2008 9:48 am

We have a Suburban SF 25F, last night it blew cold air long enough to get to 45 in the camper and wake me up – it was 8 outside. I turned off the furnace for a while, then turned it back on, it blew warm air for about 15 minutes, then the air turned cold again. Any help or suggestions would be great…thanks!

Pat in Nevada Reply:
December 18th, 2008 at 2:19 pm

Where in Nevada? We are in Dayton, NV Having trouble with our heater, too, and we installed it NEW last Dec., fan but no flame. Already replaced the igniter, twice!
But this time it isn’t fixing the problem. Further troubleshooting needed. Temps near 0 now. Sure can’t afford to buy another new heater @ $700.00 Any suggestions out there????????

Chris Reply:
December 18th, 2008 at 2:32 pm

On that model I have found the limit switch is the most failure prone part- you can easily get to it from inside the rig- there will be n access panel (the whole inside panel) that is held on by a couple of screws, and the limit switch is right behind it- it’s a small oval switch with two wires leading to it.
Often simply disconnecting and reconnecting the wires will fix it for a while.

Patricia on Thu, 18th Dec 2008 2:10 pm

We live in a 1979 35ft Komfort fifth wheel and had a Suburban NT30SP, which we had to replace exactly one year ago with a supposedly NEW one (from an RV supplier), same model. We have already replaced the igniter a month ago, and now the furnace is doing the same thing again. We bought an extra igniter last month, but that isn’t working. Still have the same problem, fan but no flame. Are we going to have to go throught this every winter? We lived in the RV for 10 years before we had to replace the heater. And with the new heater, seems as though we may have a lemon. Any recourse with that?

Chris Reply:
December 18th, 2008 at 2:37 pm

Hi Patricia,
That really isn’t normal- really the only design problem I see with the NT series is that the circuit board is too close to the combustion chamber- Dinosaur makes a board extender which will move the circuit board outside the case, which both keeps it cooler and makes it much easier to troubleshoot.
That said- I would closely look at the installation- especially supply and return air flow, as well as trying to bypass the thermostat to test.

Pat ricia Reply:
December 18th, 2008 at 3:22 pm

Already bypassed thermostat. Heater was working fine this morning at 6:30 when we turned thermostat up (we turn it lower at night). But by 7:00 it was no longer igniting.

Pat on Thu, 25th Dec 2008 10:45 pm

I have a Suburban NT30sp when I turn it on and adjust the thermostat to a high temp, the blower comes on , but the burners do not light and I can’t hear the igniter sparking, want could be the problem

george on Fri, 26th Dec 2008 8:08 pm

My old duo-therm just stopped lighting up, the blower comes on but no heat. I replaced the controller board with a 50 plus board. Now the blower comes “ON”, I hear the igniter and smell the gas coming out the exhaust, but it just won’t light up. I have tried adjusting the air shutter, but it just won’t light. Any ideas?

Bill Zimmerman on Sun, 28th Dec 2008 1:56 pm

1st, thank you for what you are doing here!

I have an 06 Laredo with a Suburban NT-30SP heater and a Colman Mach thermastat (Air & heat)

I have had the unit in shop several times for this problem, but they could not resolve.

Problem: Heater comes on, heats, cools down, turns off and then immeditaly turns back on. It will stay on for several minutes, (No heat) turn off, and again immeditaly turn back on. This cycle continues untill I turn off at thermastat.

I need to use this unit this week for additional rooms as family is staying for wedding.

Thanks again for this,
Bill Z

Bill on Sun, 28th Dec 2008 6:04 pm

Chris,

I have a 1976 Winnebago Brave. My furnace won’t stay lit, but when I relight the pilot, it stays on until I turn the furnace on, then the pilot goes out. I have changed the tanks and regulator and hoses, and now the pilot won’t stay lit. I bought a thermocouple, but don’t know how to change it. Any tips, and do you think that is the problem?

Thanks,

Bill

shelia d. hobbs on Wed, 7th Jan 2009 2:26 pm

I would like to know why my furnace blows cold air after running for a while, it doesnt do this all the time but every once in a while it starts to blow cold air and I have to turn it off and re-set it.

Anonymous on Thu, 8th Jan 2009 9:54 am

Why does my furnace click on for 3 seconds then clicks off, then back on again and stays on till it reaches temperture?

Scott Poynter on Sun, 11th Jan 2009 5:15 pm

Hey Chris, I have a Suburban nt30s in my RV. When I turn the thermostat on, the blower will come on and the electrode sparks but the pilot does not light. I repeated this about 10 times and still no pilot. Any Ideas?
Thanks, Scott

Chris Reply:
January 11th, 2009 at 5:53 pm

Hi Scott,
It sounds like it isn’t getting fuel (propane). The “quick and dirty” check for a sticking gas valve is to take the front off the furnace (so you can see when it’s trying to ignite), and when it fires the spark, give it a good sharp whack on the gas manifold- not too hard, but a sharp thwack.
The bad part is that if it ignites, you will have to replace the gas valve, as while it may work for a while, the valve could be leaking (not real common), and it will likely fail again at the worst possible moment.

John Beal on Mon, 12th Jan 2009 2:39 pm

I have a heating wall furnace and it will not cut off. The fan runs and the heat runs. I have replaced the thermorestat and it still will not cut off when you turn down the temperture. I disconnected the power from the gas control and then the gas burner cut off and the fan ran till the temperture dropped like it should. Do you know what could be wrong. Can I fix it or should I call a repair man.

Jim on Tue, 13th Jan 2009 11:17 am

I am having an odd issue I haven’t seen posted yet. I have a Suburban Nt series in my 33′ Komfort ducted unit. Last year I had the issue of the furnace not turning off when it reached temp. It only happened occasionally. This year it started right away so I replaced the Thermostat, that seemed to help for awhile and now it is doing it again. The furnace was replaced about 2 years ago, but the thermostat was the original so Replaced it with an identical new one. Thermostat is Duo-Therm and does control the Roof top AC. Any suggestions would be great!

bomani on Sat, 17th Jan 2009 6:50 pm

i have three circulators for three floors in my home. the basement works the second floor works however, the first floor dosen’t work. i replaced the circulator pump and noticed it dosen’t work is it possible there is a seperate relay for the first floor. how do i test this i have an electronic reader.

bomani on Sat, 17th Jan 2009 6:56 pm

i have three seperate floor with 3 different circulators. one of them isn’t working how can i test this. by the way i replaced the circulator already because it wasnt working. does the relay seperate them and can i check them seperate

eddie on Sun, 18th Jan 2009 12:56 am

hi i am home owner and i have problem with my furnace ,if somebody can help me with this i will thank , well the problem is when i turn the thermostat to heat the condensing unit out side it come on and turn off and some time stay on so is blowing cool and warm air and the same time i dont know if the problem is the fan control board thanks u

rebecca on Mon, 19th Jan 2009 9:03 pm

We recently moved our Shadow Cruiser 5th wheel and when we turned the heat on the fan made a horrible racket and the lights went dim and it blew the fuse. It has been doing this ever since. Is it the motor or something else?

steve on Thu, 22nd Jan 2009 11:48 pm

We have an Attitude Trailer with a Suburban SF 30 Furnace. The furnace will not stop blowing heat, even with the thermostat in the off position. We replaced the wall thermostat but it didn’t solve the problem.

Eric on Sun, 25th Jan 2009 3:11 am

I have a Hydro flame furnace and thermostat in my ‘92 Dutchmen ct. We’ve had a number of problems with the furnace over the last four years, but partially with the help of your page, I’ve been able to always get it going again. But recently it pulled a mind scramble on me and just quit working at all. I mean completely lifeless. No noises or actions of any kind. So far I’ve cleaned thoroughly the entire unit and it’s components, bought a new motor (being careful to draw a color coded wiring diagram before taking everything apart) but once back together there was still no life. I bought a new deep cycle battery and replaced the cable ends but still no sign of life. Next I cleaned and rebuilt the thermostat, replacing the sensor wire in the process and checking that the anticipator is set correctly but still no life I haven’t a clue how to use a multimeter or manometer even if I had one. I really need a good clue as to where to go from here. Tired of wearing coat and hat in the house.

Matt on Wed, 28th Jan 2009 11:58 am

My furnace has a wild occasional problem. The ignighter comes on, then the three burners, and after about 3 seconds. the burners cut out and resets its self. It will do this about four times then completely turn off. After 10 minutes it will cycle normally for 2 times and then after those cycles it repeats its self with the burners cutting off. The gas valve is on ive checked the grounds and the flame sensor and flame rollout switch.

Kathy on Fri, 30th Jan 2009 12:19 pm

I have a 07 KZ Montego Bay F/W. The air flow going into the bedroom is very low and I have to set the thermostat to approx. 78 deg for it to run long enough to heat the rig. When the furnace shuts down it comes right back on again sometimes in as little as 30 sec. I have plenty of air flow to the living area. The furnace is located in the basement area. What could cause low air flow to the bedroom and why does the furnace turn right back on after shutting down?

(reply)

sidney mcwhorter on Sun, 1st Feb 2009 10:44 pm

I have a 2003 keystone tailgator 5 th wheel ,329t5. Furnace works good, so I think. I just got this camper and this is my first time using it. Furnace comes on and heats good, cycles, but the floor vent closest to the furnace is so hot that it will burn your feet. When I got home from a trip I noticed that the plastic lovers in that vent had gotten so hot that it warped the lovers out of shape. Any thought on this will be appreciated. thank you sid

Pete on Mon, 9th Feb 2009 2:33 pm

Gas Furnace combustion blower continues to run for long period after thermostat has shut off burner. Runs 15-20 minutes before turning off. All else works OK.

-Pete, in Tacoma WA

Chris Reply:
February 9th, 2009 at 6:30 pm

Hi Pete,
That sounds like the fan relay- a time delay device.

Ron on Sun, 15th Feb 2009 8:46 pm

hi chris ihave a sf30f that worked great until late fall it just wont spark i have removed the furnace and ohmed out the ignition wire and is good. blower kicks on correctly just no spark ………….my theory is the curcuit board is bad…..is there a way to test the board?? sail switch ok , and relay swich is good however i am trying to test w/o propane hooked up but im assuming that should not affect the ignition spark. obvisously no flame of course

rwh on Fri, 20th Feb 2009 3:17 pm

furnace comes on, fan gets speed, element heat up; then no gas,element cools ; this repeats a few times, then shuts down. help me if you can.

Jack Reply:
March 18th, 2009 at 1:40 pm

Look at replacing the gas solenoid combination valve, I paid $119, Mine was getting current but not always clicking open as to be expected 15 seconds after fan starts and ignitor heated up.

Art Dill on Sat, 21st Feb 2009 7:16 pm

Hi, Have a Suburban SF30F propane furnace which responds as such: Fan comes on, ignition,
element heats up, flame goes out, ignition again, element heats up, flame goes out, ignition
again, element heats up, flame goes out, element cools off, several minutes later the fan turns off.
Problem remains even with thermostat jumpered, combustion chamber cleaned out, igniter
aligned to burner. Do you have any suggestions ?

Chris Reply:
February 22nd, 2009 at 9:52 am

Hi Art,
I would look at the limit switch, which seems to be the most failure prone part of that model, in my experience.

ron dernick on Thu, 26th Feb 2009 3:45 pm

IMy furnace was working but then about every 2 days or so the fan would kick on and then I wait to here the flames ignite and nothing happened. I wen into the basement and switched the furnace off and on and then the fan went on-the ignition senmsor got red and the gas fired up. I put in a new electric ignition sensor and still have problems-every once in a while the fan starts but the electirc ignition sensor.

FRED on Thu, 19th Mar 2009 1:25 am

Have an atwoood excalibur 8500-ll furnace. Just found out the burner assembly is totally bruned out. The electrode is ok. What effect does a burnt out burner assembly have on the operation of the furnace? Would it cause the furnace to light and run for a few seconds then shut down?

robert on Sat, 28th Mar 2009 5:26 pm

I have a lennox gas furnace I replaced the thermocouple this fall It was fine untill 2 months ago the pilot light keeps going out whats wrong?

Dan on Mon, 30th Mar 2009 11:49 pm

I have a Suburban SF-35F furnace with a Dometic analog t-stat, heat/cool only no heat pump or strip. The furnace has a recently installed Dinasaur board. It works fine by connecting the two blue stat wires but when I pulled the furnace I didn’t label the blue wires coming from the wall. How do I know which stat wire goes where? One of the stat wires coming from the furnace is always hot as the other is not. Neither one of the blue of the blue wires from the wall is hot with the stat in any position. Any info is appreciated. Thank You

Paul LeDoux on Wed, 1st Apr 2009 10:27 pm

I have a Suburban Furnace model # NT24M. I am looking for a thermostat relay. Do you know where I could fnd one?

michael on Tue, 28th Apr 2009 10:23 pm

I have a 2005 vortex toy box 27 foot the furnance wont light the blower comes on, and runs for a few minutes but the heater wont light , than the blower will shut back off. Any suggestions

MASTC on Sun, 3rd May 2009 11:54 am

Hi Chris, enjoy your website. I have a 94 wilderness with a Hydroflame 8525 ll. The blower kicks on and the flame will ignite for 4-6 seconds then lock out. I’ve pulled the unit out and have hooked it to 12 volts – propane. I’ve also pulled the burner unit out to physically see what it is doing. I have been performing T/S on the bench. However I haven’t been able to find a service manual that will give me specific info & specs. I have confirmed the 12v back to the circuit board thru the sail & limit switches. I have also tryed preheating the thermocouple. No change. Next I have been measuring the volt change of the thermocouple back at the circuit board. I can see voltage change during the 4 seconds the burner is lit. I am wondering how much voltage the circuit board wants to see. note: the thermocouple doesn’t look damaged in any way. Help?!

Anonymous Reply:
October 28th, 2009 at 4:28 pm

check for a wasp nest in the exchanger

Bill on Thu, 7th May 2009 10:11 pm

Hi Chris,
I have a Suburban gas furnace and it will not run. I checked the t stat and in furnace mode I was reading from ground to furnace 0 vdc. I switch to off anf from ground to furnace I read 13 vdc. shouldn’t it be the other way. Also when in furnace mode and I turn the fan from auto to fan only the A/C fan comes on. Any sugestions. Thanks

Dan Crocker on Sat, 9th May 2009 2:15 pm

Chris,
I have the same problems with my 07 Sudurban 35 as your other troubled writers. Blower starts, spark-board attempts all three times, you can smell gas outside – but no firing! Replaced the regulator 6 months ago, and then it worked for a few months – - can’t believe that they fail that often?! If this many people have this many problems, is there some other manufacturer that makes a reliable replacement unit with easy access for annual cleaning? I started full time RVing 3 years ago – but these furnace problems are a real pain and the worst headache of all maintenence!! Design a furnace that lasts, and become a millionaire Chris!! Thanks, Dan

Jack Biggs on Sat, 23rd May 2009 8:27 pm

I have an Amana Gas-fired warm air furnace and / Amana ac remote condesing unit. 3 years old, last fall I had a board replaced in the furnace it would not work. Now today the fan won’t start , AC won’t work, furnace won’t work. Making me crazy and broke I’m a senior on fixed income. Please any suggestions

Anonymous Reply:
October 19th, 2009 at 2:06 pm

Your problems sound as if I wrote the paragraph. My Amana is seven years old and I have a problem every year – -chip board etc, and service calls. Where do you get sevice for Amana without paying outragous price.

Robert on Wed, 27th May 2009 4:46 pm

Chris
I have a Coleman furnace (dont remember the model) in a mid 70’s road runner. it is set up for 110v or 12 v . but on 12 v it doesnt seem to kick over from pilot to burn. It has the glow coil to light the pilot and on 110 its fine but on 12 v it just wont quite do it. but yet the 12v batt will run the fan just fine . if i take a set of jumper cables and hook up to an extra batt when the burner clicks( trying to light) i can get it to work. any help? thanks…

kristian on Thu, 28th May 2009 7:24 pm

Your suggestion sounds great; however, I have a hydro flame furnace (8516), and the thermostat (Robertshaw) burns out, making it a little difficult to measure the amps across the thermostat. I presume something is drawing to much current, and I would like to measure it. It worked fine the first night on our last trip, but the next night there were no heat. Back home I replaced the thermostat – a flash – and it was burned out to. I am connecting the the hot wire to the pole marked red common. Any suggestions or help please! Thanks.

Brian on Sun, 21st Jun 2009 10:12 am

I recently installed a Carrier condensing unit line set and A-coil for a friend. I wired everything back the way I disassembled it. The cooling unit ran fine all night except the electronic controlled t-stat failed to control to set point. The person said it coled the house down fine but in the middle of the night they got too cold and when they looked at the t-stat they realized the room temp was lower that the set point. They manually shut the cooling off and when they got up the next day the house was hot and they went to turn on the cooling on the t-stat nothing happened. I thought it was a t-stat issue so I replaced it and still no cooling. I can manually force the contactors on condensing unit with a screw driver on but not automatically.The same can be done with the fan on furnace. Can you tell me what the issue can be?? Do I have a bad circuit board due to something the person did when they manually shut the cooling down the first time?

Thanks,Brian

Kurt on Tue, 23rd Jun 2009 1:21 pm

Hi, I have an Atwood Hydroflame 7920-II model furnace in my Coleman pop up camper. When I turn the furnace on at the thermostat, the fan kicks on and runs, but it does not blow hot air. If I leave it on it just keeps running and doesn’t shut off, any body have suggestions on basic issues that I can check out to try and fix this?
Thanks,
Kurt

ken on Fri, 10th Jul 2009 8:50 am

have Suburban furnace model# SF 30F with a valve shut off switch which i cannot locate,any ideas??

Chris on Fri, 10th Jul 2009 12:39 pm

It should be attached to the blower cover, accessed from the outside- but.. if you don’t have an outside removable cover, you will have to pull the furnace to get to it.

csklatt on Mon, 13th Jul 2009 9:12 am

I have a Suburban SF 30F furnace in my 2008 Tango and the furnace has ran almost every night since we bought the trailer. We live in Canada so it does cool of at night. My furance would kick in fine but it would not light. We can smell propane coming out the exhaust and we can hear the ignitor clicking. Once and a while we can fell a warm puff as it does light for a split second. The only way we got it to light was to tap off a third of the air intake then it ran fine. To me if looks like an air / fuel mixture problem. does anyone know if the air / fuel can be adjusted?

Morgan on Tue, 14th Jul 2009 11:23 am

I have an older Coleman furnace in a 1978 motorhome. After winter vacuum of dust and rust from pilot, replaced thermocouple, etc runs like champ again. However, when the thermostat shuts off, the flame and fan all shutoff together. Is that OK, seem like hot shut down with no cool down would be bad for it. Any suggestions would be greatly appreciated.

Morgan

Chris on Tue, 14th Jul 2009 12:10 pm

It really isn’t adjustable, but from the symptoms I would bet you have either low LP pressure, or a partially clogged orifice.

Chris on Tue, 14th Jul 2009 12:11 pm

There should be a thermal fan switch in the blower circuit which keeps the blower running for cool down.
But… you do have to run it long enough to heat the switch up before it will engage.

Kathy Chapman on Sat, 18th Jul 2009 7:12 pm

Hello Chris: We have a 2000 Flagstaff tent trailer. We have had the trailer out several times this year and the furnace worked GREAT! On our last weekend out, we blew a circuit in the trailer, but were able to reset it, and we believe the furnace came on that night as expected.

Last weekend though it was a bit chilly at night, so we turned on the thermostat, but the blower only blows out cold air now. We have checked all the fuses and circuit breakers in the panel and all looks good there.

My husband has checked and the fridge and propane stove are working. He checked and the propane tank is full (in fact it was filled just before we went out last weekend)

Is it enough information to suggest where we should start? Thermostat?

Ty on Fri, 31st Jul 2009 10:21 pm

We have a Suburban Furnace in a 1982 Starcraft. Model# GT-10DB. We light pilot, and when we turn the knob to ON the pilot goes outt. One day we were lucky enough to have it stay lit when turned to ON position….but no blower, or any fan noise. Any help appreciated, as husband and myself are fighting over it constantly!

Dan Cohen on Sun, 30th Aug 2009 11:09 am

Chris – this is a great website! I have a problem with my Suburban furnace in that it keeps blowing the 15 amp fuse. When I turn the stat on nothing happens. I have been able to get the blower to come on by manually spinning it and turning on the stat and then it starts to function and even the works properly at that point, but after about five minutes it blows the fuse again. Do I have a bad blower or is the relay toast? Is there a way to clean the blower if that is the problem in that it is just dirty and won’t spin thus drawing too many amps and blowing the fuse. I did just replace the Tstat as the old one was not working at all. I did not look at the anticipator but will set to .7 on monday and try again. LMK if I need to try something else. Thanks!

Tony Cobuccio on Mon, 31st Aug 2009 11:31 am

I have a Suburban SF-30F and used it for the first time this season. The unit turns on and runs also shuts off at set point. The only thing that is bothering me is the popping sound coming from the exhaust port. I pulled the unit out and cleaned found nothing significant. The hot water heater works fine with nearly full propane tanks. Any thoughts? Thanks

Jean on Fri, 4th Sep 2009 2:54 pm

Hi all>> Ok, I have a 92 40′ fifthwheel Alfa to be exact. Had issues with original furnace so they put in new Suburban N40 I believe. It worked a few times then stopped. They came back. Took it out and to shop. Brought it back and it worked a couple times and went out. They took it back to shop again and brought it back and it worked about three times and quit. This has gone on for months and finally the company that was working on it gave up and said he does not know what to do. It will not do anything, no click or nothing. I even tried putting in new ignitor but nothing. I don’t know what to do now as they won’t even try to repair it anymore. It cost over a thousand dollars for the furnace and I don’t know how much for all the travelling and repairs but it was a lot.
HELP PLEASE. Winter is coming and I live in it.

Daniel on Sun, 6th Sep 2009 9:15 am

Thank you for what you do.

Interesting info in this blog…I believe I have my issue isolated but would like to confirm. Hydroflame 8500 starts and heats correctly, but after flameout, the blower continues to run…..forever. The relay is hot to the touch while running and of course when I unplug the wire going to the blower, it stops. If I plug it back in immediately, it will resume running. If I wait 5 minutes or so and plug the wire back in, it stays off until the thermostat calls for heat again and the scenario replays itself. Any help is appreciated.

Thank You,

Dan

Chris on Sun, 6th Sep 2009 5:06 pm

Hi Daniel,
I would say the fan relay is bad. While this isn’t terribly common, I have seen it before.

Pierre on Mon, 7th Sep 2009 9:54 pm

Glad I found this blog.

My problem is unusual. My funace (Suburban) goes on fine. Once it reaches the set temperature it also shuts down properly. But then when the ambient temperature goes down the furnace never goes back on. What I need to do at that point is bring the thermostat’s set temp down and then right back up and the cycle described starts ober and over.

Please help me…. I was up all night playing with the thermostat… trying not to freeze !!!

Beau on Tue, 8th Sep 2009 4:05 pm

Chris- I have a 90 Hydro Flame 8500-11 that when I turn it on the blower works fine but it won’t ignite. If I turn the thermostat down and then back up the fan continues to blow and the burner ignites. The next time it kicks on the same thing happens. The blower will run for hours because it never ignites unless I manually play with the thermostat. I have also replaced the thermostat. Any ideas. All other gas appliances work fine. Thanks for your help.

Daniel on Fri, 11th Sep 2009 6:53 am

Thank you Chris. As suspected the fan relay was bad. Replaced it at a cost of 36.00 and it now cycles the fan off after burner cooldown period. Problem solved.

ali on Wed, 16th Sep 2009 10:51 am

I have a Rheem Corsaire gas furnace (cat 1 forced air) and when the furnace is off there is a continual buzzing sound. It sounds like a motor running but I can’t feel any vibrations or pinpoint the origin. Any suggestions? Thanks!

jACK on Sat, 19th Sep 2009 8:22 am

I have a 76 camper with a duo-therm. Every time I turn it on it keeps blowing out pilot

Wayne Diggins on Mon, 21st Sep 2009 9:26 am

Hello Chris,
I have 2 Suburban Furnaces in my 85 Bounder. Sf=20 and sf-35 and neither will ignite now. I put the dinasour board from the sf-20 in the sf-35 and it ignited a few times then it quit igniting, . I’ve replace both limit switches and the sail switch in the 35, but no avail. I also replace the themostate for the sf-35. Is it possible that they are not getting enough voltage, or do they need grounding?? I also had the sf-35 serviced a couple of years ago, but I took the unit in not the RV. Please help, it looks like their is alot of people with this same ignition problem. Thanks. Wayne

Al Barrs on Fri, 25th Sep 2009 2:25 pm

Hello Chris;
Last winter while at my hunting lease my Suburban NT30SP RV Furnace would work fine for several hours and then after it cut out after reaching the thermostat set temperature the blower would come on but the burner would not light until I got up and recycled the system using the thermostat…turned it off and after a few minutes turned it back on. Sometime it would go fine until morning and at other times it would repeat the fault. I have purchased a new temperature limit switch. Do you think that may be my problem? Thanks, Al Barrs albarrs@wfeca.net

Wendy on Sat, 26th Sep 2009 10:37 am

I have a 2003 Keystone (sprinter) 5th wheel. The furance works sometimes. You can feel cold air blowing and that it is try to click on. So we run it for awhile turning it off and on no hot air. Then I tried it again the next day and it worked. But 2 days later did not worked. I think this thing has a mind of it’s own. Do you think you can help me out. Please it is getting pretty cold at night up here in eastern washington state. Thanks Wendy

Dennis Reply:
October 17th, 2009 at 12:00 am

Well Wendy, you could always park that 5th wheel down here in FL .. it was 85 degrees here today and rarely goes into the 50’s in S. Florida – in the meantime, have ya fixed that pesky furnace of yours? LOL

Rob on Fri, 2nd Oct 2009 11:43 am

My trailer furnace flame is to yellow, I cleaned the burner but that didn’t help.
Thoughts?

Thanks,
Rob

Tina on Mon, 5th Oct 2009 10:45 am

Hi, I need help with our furnace! We just got a Keystone Outback travel trailer 26rs which has a remote for the ac/furnace. We bought 2 new marine batteries and had the generator on, tried the ac and it worked fine….changed the mode to furnace and increased the temperature and nothing. We tried everything and nothing is happening. Can you help?

leonard andrews on Mon, 5th Oct 2009 2:36 pm

have a Atwood furnace model 85-11, the blower comes on, but on heat. I’ve played with the thermastast, no heat what could be the problem

leonard andrews Reply:
January 28th, 2010 at 3:20 pm

is it possible to get a list of componants location on the furnace..

jennifer on Tue, 6th Oct 2009 3:53 pm

i have a problem. I have a 1978 dodge commander with a duo therm 65920-041. The pilot light stays lit. Has been lit for the past 2 days. The problem im having is that when i turn the thermostat on (ive kept it on for 2 days also) the blower doesnt work at all. No noise no nothing. It has came on one day. I was cooking.. I heard it going and got all excited… Then the next day.. Nothing. Any ideas?

John in Miami Florida on Wed, 7th Oct 2009 3:05 pm

Hello I have a Suburban SF-25F LP Gas Furnace. The unit works BUT when it is turned off I can smell a small amount of LP gas coming from the outside exhaust vent of the unit. So far from the internet I have learned that # 1 the valve could be bad or #2 the electronic module could be bad and be sending current to the valve allowing it to open. How do I do I figure out which one is bad?

Tabitha on Wed, 14th Oct 2009 3:51 pm

I have a very old International furnace, we recently just moved in and are trying to save on cost. We have comepletely cleaned the furnace and it is obvious that it hasn’t been maintained in years. The flames are very high and orange, and when we adjusted the regulator to where the flames are blue and 1” high the last burner goes out. Do we need to replace the gas regulator valve, or is there anything else you could suggest before we call a proffesional?

Antones on Fri, 16th Oct 2009 5:16 pm

I just installed a replacement burner motor on my older forced air oil furnace. the system fired up perfectly after bleeding the line but quits firing after 10-15 min! The forced air fan kicks up when limiter triggers it, but burner shuts down when it reaches its 200 mark. Fan keeps going for another 10 min but burner never automatically fires up again, unless I manually reset the furnace relay botton.
(NOTE: The red reset relay is cranky…I often have to push it repeatedly for it to engage & fire up.)
A) Why is the burner reaching it’s limit so soon?
B) Is the furnace reset relay defective? (preventing burner from refiring automatically? And since I may also have damaged the Fan/Limit switch by not holding down the disk while resetting;
C) Could BOTH Fan/Limit switch & Reset Relay be causing the short firing time?
( I have not yet cleaned out the stacks)
Thank you for any suggestions or clearing any missconceptions…

Antones

Anthony Guerra Reply:
February 5th, 2010 at 2:12 am

Hi I have tha same problem that i am working thtr.I am wondering if you figured out the solution?

Anthony Guerra

ak on Sat, 17th Oct 2009 9:13 pm

We have a stationary RV. My wife and I were just up to close up for the season. I had just been up myself to the trailer about three weeks previous and torned the heater on, which seemed to work fine. Before I left I turned the thermostatat down all the way as usual before I left.
When we arrived and opened the trailer the blower was on. I don’t know how long it had been on. I finally opened the circuit breaker panel and shut the circuit off. This circuit also handled the trailer ceiling lights and several outlets.
I was going to turn the propane on and see if the heater would fire up but was reluctant too. It was extremely cold so we had to get a room at a local motel.
The next morning we returned and when I turned on the circuit the blower fan went on again so I re-shut off the breaker.
Later that day after installing anti-freeze in the water lines I had to open the circuit to turn on the water pump. This was the same circuit as the blower. When I re-set the circuit breaker this time the blower fan did not come on.
My first thought is that it might be a faulty thermostat, which I plan to replace to see if that’s the problem.
My questions are:
1. Could a bad thermostat be a reason for the blower fan to just start on it’s own?
2. I didn’t get the name of the furnace before we left (5 hours away). Can any thermostat be installed? The type I have has a lever on the botton but it does’nt seem to move so I never really touch this lever. The lever at the top sets / regulates the tempeerature and this is what I use to turn the heater on and off.

ak on Sat, 17th Oct 2009 9:18 pm

We have a stationary RV. My wife and I were just up to close up for the season. I had just been up myself to the trailer about three weeks previous and turned the heater on, which seemed to work fine. Before I left I turned the thermostatat down all the way as usual before I left.
When we arrived and opened the trailer the blower was on. I don’t know how long it had been on. I finally opened the circuit breaker panel and shut the circuit off. This circuit also handled the trailer ceiling lights and several outlets.
I was going to turn the propane on and see if the heater would fire up but was reluctant too. It was extremely cold so we had to get a room at a local motel.
The next morning we returned and when I turned on the circuit the blower fan went on again so I re-shut off the breaker.
Later that day after installing anti-freeze in the water lines I had to open the circuit to turn on the water pump. This was the same circuit as the blower. When I re-set the circuit breaker this time the blower fan did not come on.
My first thought is that it might be a faulty thermostat, which I plan to replace to see if that’s the problem.
My questions are:
1. Could a bad thermostat be a reason for the blower fan to just start on it’s own?
2. I didn’t get the name of the furnace before we left (5 hours away). Can any thermostat be installed? The type I have has a lever on the botton but it does’nt seem to move so I never really touch this lever. The lever at the top sets / regulates the temperature and this is what I use to turn the heater on and off.

Kyle on Sun, 18th Oct 2009 9:26 pm

Hi Chris,
I have an early 90’s model Suburban sf35f. My problem is that the burner will not light now. I can smell propane out the exhaust and i can hear the igniter try to light. It was working last year but we had a problem. we had to open the steel cover on the furnace housing to relieve pressure/vacuum and it would light. With the cover on, it would not. now the burner wont light at all. Cleaned everything i could inside. I originally had to replace the blower motor and also replaced gaskets. one of the gaskets to the blower assembly was damaged but not bad. Any suggestions? Thank you and appreciate the help

Anonymous on Sat, 24th Oct 2009 6:48 am

how does the auto button on a thermostat work… when does it come on when you set it to a certain degrees. if i set it on 75. then how does this work. is it best to leave it on on or auto… im concerned on my heating bill this winter..

sli on Sat, 24th Oct 2009 12:46 pm

I have a RUDD UGDG_ series FURnaces with hot surface ignitor and I can’t get the bunner to come om ,the fan come on and the switch click on but the the bunner still wont come on , why?

sli on Sat, 24th Oct 2009 12:48 pm

Yes send a picture to go with my comment

Jessica on Mon, 26th Oct 2009 4:55 am

Hi! I have a Hydroflame 8535 III — it is the model with an extra ventilator board, which they no longer have parts for. I replaced the motor and Atwood gave me direction how to rewire it to bypass the ventilator, but after many arguments with them, it just wouldn’t work. So I hooked it back up how it was and it went for a couple years, except the fan had to be on high nonstop–there was no more automatic on/off. Anyway, last year the main board went, replaced that–everything back to normal (besides no auto). This year, the fan shut off while the furnace was still hot and wouldn’t come back on. While testing (or pretending to) I crossed the prongs of my tester whlle they were touching the top and bottom relay forks and the fan turned on. I thought “voila!” the relay is bad, and/or the thermostat. So put new ones on. Then wired again the way Atwood said to because the new thermostat is not for ventilators….and still doesnt work. When I turn on the new thermostat, the furnace actually keeps firing and trying to start, but the fan doesn’t even try to come on. Back outside, and jump the relay and the fan starts right up. I don’t get it! Do you????

Anthony on Mon, 26th Oct 2009 8:08 pm

I have a Suburban furnance in my RV that when I set the thermostat below 60 it will work fine – cycle on and off like it is supposed to. However, when I raise it above that it will give a popping sound, almost like a cough. It appears to be at the temperature to cut off because all I have to do is touch the thermostat and it will click. I have had it in the shop two times and they can’t seem to find a problem. I need some help with winter coming.

tom on Wed, 28th Oct 2009 7:25 am

I havea Suburban nt30 furnace which was running great until I left the thermostat set at 50 and the RV in storage this fall during a cool spell. On returning a week later we found the blower motor running slowly and the battery voltage very low. Now after a good battery charge the furnace runs through the normal cyclw but will not ignite. Any suggestions as to what to look for? Idid note the blower air flow seems week. Also I had a full tank of propane and on return we had about 1/3 a tank left. So I assume the furnaceran until the battery level got too low to allow ignition. Thanks

Syhann Fulton on Thu, 29th Oct 2009 12:50 pm

My furnace runs and you can hear the fan kick in but it wont blow through the ducts. The house stays somewhat warm but can figure out why it wont blow. This furnace has been replace a couple of years ago and this model doesnt have a pilot light. So what could be causing the lack of air flow?

Bernie on Fri, 30th Oct 2009 6:13 pm

I have a 2006 Keystone Outback, and it has a Suburban gas furnace. Last year it quit working, the blower would come on but it would just blow cold air, and I could here a clicking noise as it were trying to ignite but it wouldn’t. I blew out the out take valves on the outside of the RV with a portable air compressor and it started working again, but after about ten minutes it started blowing cold air again, and I still here the clicking noise as if it is trying to ignite. Any suggestions?

william on Tue, 3rd Nov 2009 5:04 pm

I have an Atwood model 8535-iv-dclp the fan comes on fine but no heat it fires up and shuts down fires up and shuts down with in seconds help help

Chris on Sun, 8th Nov 2009 10:06 pm

You seem to be the man on this subject, however, you have specified that you do not cover mobile home systems…I’m hoping you might have gained some knowledge in this area, or failing that , might be able to refer me to someone that might help with a propane flow problem. The tanks are full, the furnace has a new thermocouple, however the system ran dry of propane last year and since then I have had the tanks filled, but I cannot get the pilot to light, with direct flame, (bbq lighter) and there was a cold winter in the interim., (posssibly freezing moisture in the lines?). now it is summer…ish, tho the system will still not light…I believe that this is not an issue with flame level, (tried to light with the aforementioned lighter), Could it be a regulator issue, or the furnace “controller” it is an old intertherm, (very old, firebox in good shape).
Locally, the cost for a “professional” is $137.50 per 1/2 hour, so as you might understand, I would like to get this done uhhhh, myself, with alittle help from my friends…

Thanks
/chris

DAN Reply:
December 10th, 2009 at 4:15 pm

May be able to help you..very knowledgeable on Mobile home Coleman and Intertherm/Nordyne elect and gas furnaces.

Glenn on Mon, 9th Nov 2009 7:42 pm

Chris,
I have a SF-30. The unit ignites, burners run for a few seconds, then go out. Tries to ignite 3 times then quits. Voltage & tank pressure seem good.
I shorted across the limit switch, still the same problem.
Any suggestions?
Thanks in advance,
Glenn

john on Tue, 10th Nov 2009 11:49 am

i have a Coleman propane furnace with a Coleman thermostat to got with it but the problem is the thermostat is not adjusting right it slides all the way to 75 and 80 at the top of the scale the furnace runs good when it runs it is a mach thermostat what is the problem thanks john

Alex on Tue, 10th Nov 2009 12:59 pm

Chris, I have two Carrier Air V units on my camper. One unit is a heat pump. I was operating with the heat pump unit and woke up very cold. When the heat pump quit heating because of the outside temperature the furnace did not start. I tried to start the furnace with the other unit and it did not start from the thermostat in the unit. I first thought I had problems with the igniter in the furnace. I had someone operate the units and listened for the sound of the pilot light starting. No sound. Then I depressed the emergency start button on the HP unit for the required 5 seconds and the furnace did start. I then checked the other unit and it did also. My thought was that I had a bad thermostat but it is not usual for two to go at the same time. Then I saw some thing in the service manual about raising the temperature 10 degrees above room and waiting for a minute. My camper is two hundred miles away so I will not get to experiment again until Wednesday. Do you have any suggestions?

Magnolia on Wed, 11th Nov 2009 6:18 pm

Hi Chris,
I’ve been reading the great advice you’re giving to others and I was just wondering; can you help me find a website that can help me with the kind of furnace I have, troubleshooting, cleaning maintaince etc. All I really know is that it’s a 119 series gase fired furnace. I don’t really see a brand name on it, but when I had it serviced I’m told get rid of it and get a newer furnance. The people that service is also nthe people that selling them as well. Waht’s your advice? Thanks!

Magnolia on Wed, 11th Nov 2009 6:24 pm

Hi Chris,
I’ve been reading the great advice you’re giving to others and I was just wondering; can you help me find a website that can help me with the kind of furnace I have, troubleshooting, cleaning maintaince etc. All I really know is that it’s a 119 series gas fired furnace. I don’t really see a brand name on it, but when I had it serviced I’m told get rid of it and get a newer furnance. The people that service is also nthe people that selling them as well. What’s your advice? Thanks!

jerry. on Sat, 14th Nov 2009 8:58 pm

I find your site very informative as to troubleshooting furnaces. I just want to pass on
a little tip. My furnace would blow the fuse when changing the thermostat to Heat.
I took the furnace out of my camper to trouble shoot it.(SF 30) The fan motor would not rotate. This was caused by a very large Dirt Dobber nest inside the combustion
Fan. It was really set up like baked clay. I finally got it out and ops checked the blower motor, it ran good. Had I put some duct tape on the air exhaust port on the
outside of the camper when not in use this would not have happened. Just a thought. Thanks for what you are doing to help people.

Joe on Sat, 14th Nov 2009 9:45 pm

OK this is long so I’m going straight to the point.I’ve read a good many of the comments on Furnace Problems.Symptoms:Circles and starts and shuts down as many others have experienced : So Far I have cleaned the heat exchange and fan area,replaced the High Temp sensor,Check’s burning camber Clean,checked starting system and cleaned all parts,adjusted electrode to specs.I have read in several furnace repair forums all of the above and depending which one you read they included the circuit board,sail switch and thermostat.OK what i get from this is basically you end up rebuilding the hole furnace if you guess what to replace first.O did i mention i also replace both batteries they needed it and the propane regulator.Also i have got it to run on three occasions in the last 2 weeks for up To 8 hours shut it of and the problem starts all over.Frustrating you know what i mean!GOOD NIGHT ALL

Patty on Sun, 15th Nov 2009 3:00 pm

We have a Suburban heater in pop-up camper. We always run on electricity, not battery. It has been working fine for several years, but this weekend the flame would not ignite. The fan blows, I hear a click sound as though it’s trying to ignite, but no flame. I just happened to hit the breaker for the DC. The igniter lit! It runs fine, warm air, and when it reaches the set temp shuts off like it should. But when the temp cools and it tries to kick back on, no flame. Press the breaker and it lights again. Unfortunately, I can’t do this all night long! My husband, Mark, took the unit apart and cleaned it. Put it back in and still same problem. What should we check or replace next?

Jo on Mon, 16th Nov 2009 5:27 pm

I have a Coleman Evcon furnace Mdl 2DLASO56BDF in my mobil home. It started blowing cold air. Do I need to call the repair man or is this something I could trouble shoot.

DAN Reply:
December 10th, 2009 at 4:20 pm

You may be able to troubleshoot it.yourself. Depends on what the symptoms are. Main difference between Mobile Home and Residential Homes are the Heat Exchangers (Mobile homes have Sealed Combustion Heat Exchangers, which mean they get their combustion air from outside the home.

Dave on Tue, 17th Nov 2009 8:40 pm

Hi,
I have a Carrier furnace that is acting up.
I changed the thermostat batteries (Honeywell) Programmable heat/cool type.
The furnace is not turning on when the thermostat temperature setting goes under the set programmed temperature.
Sometimes the furnace will start to light and then prematurely stop and turn off.
If I turn the electronic kill switch (on/off) switch the furnace will heat up and start blowing heat.
Any suggestions you may have would be great.
Best Regards
Dave.

clyde460 on Wed, 18th Nov 2009 5:57 pm

Hello I have a miller mobile home furnace. When it first kicks on it spits sputters and rattles & rummbles; sometimes for almost a minute, Not everytime probably 80% of the time. Can you possably tell me what is causeing this ??

DAN Reply:
December 10th, 2009 at 4:24 pm

could be hard ignition.(not too safe). Also could be the heat exhanger expanding. After start up, does it seem to run fine? If so, they make a repair kit, that keeps the heat exchange for rumbling. So furnaces have a baffle at the top of the furnace, this could be loose. Miller/Intherthem-same Manufacturer.

craig on Sat, 21st Nov 2009 11:56 pm

I have a Dometic (Suburban i think) furnace SF-25F. It has been working fine for the past cold season but when i tried to fire it up today it keeps blowing the 15 amp fuse. The thermostat works both the roof AC unit and the furnace. If i turn on the heat it will be ok until the furnace tries to start then the fuse blows. The AC will run properly before the fuse bloes however. Promised the kids a camping trip but it is getting to cold to go without heat. HELP

BRENT on Sun, 22nd Nov 2009 9:46 pm

MY RHEEM OIL FURNACE BLOWER IS GIVING ME TROUBLE. I CALL FOR HEAT AND THE FURNACE LIGHTS FINE. ABOUT A MINUTE LATTER THE BLOWER STARTS. THE FURNACE BRINGS THE ROOM UP TO TEMPERATURE AND THE BURNER SHUTS OFF JUST AS IT SHOULD. THE BLOWER ON THE OTHER HAND WILL NOT SHUT OFF. THE FAN WILL RUN FOREVER UNLESS I TURN OFF THE MAIN POWER AND LEAVE IT OFF FOR A FEW MINUTES.

Scott on Mon, 23rd Nov 2009 1:04 pm

I have a Suburban nt40 furnace my problem is – I set the thermostat the unit kicks on it will blow hot air for about 3 or 4 minutes then the heat shuts down (not reaching temperature), but the blower keeps running.. The unit I think is 10 years old, but everything looks new I have replaced the circuit board, blower motor and both limit switches also replaced the power converter… Please help..

Lynn Reply:
January 29th, 2010 at 12:26 am

Get a new furnace….I have an NT40 that I have put $2K into since I purchased my 5th wheel in 2006. I put yet another $350 into it when it acted like you describe above. This time there was oil in the gas valve that caused it to shut down. After repairing the furnace, I found out that the propane tank from the gas company I use had given me an old tank that had so much oil in the bottom that it soaked my lines and killed my valve in the furnace. I had to have the lines blown out 20 times to get the oil out. Everything has run fine until tonight. The dang thing has started making noise like a twin engine plane and it probably needs to be cleaned. I have had this done before, twice, and it cost me $400 each time. I think that this time around, there might be some oil residue inside the cage that has caused it to collect more dust than usual. Anyhow…I can get a new one for $635 and I won’t have to wonder any more.

Mike on Thu, 26th Nov 2009 11:54 pm

I have a SF30 Suburban furnance in my motorhome. I can’t get the blower to kick on, so I took it to the rv dealer where I bought it. He said it was the control board, so I replaced it but still no power to the thermostat. Any ideas where to look.

sam on Wed, 2nd Dec 2009 5:43 pm

i have an hydro flame 8535 ll furnace. the internal circuit breaker keeps tripping. it will run fine sometimes for 5 minutes, then will trip. sometimes for much longer periods…. but it always trips the internal breaker. do you have any suggestions of the problem.

james taylor on Thu, 3rd Dec 2009 10:10 pm

I haave an intertherm furnace in my mobile home and the pilot will not stay on

DAN Reply:
December 10th, 2009 at 4:29 pm

If pilot goes out when you release the button/lever, only two or three things it could be. Make sure the top 1/3rd of the thermocouple is in the pilott flame.(inside the flame) If so replace the thermocouple first(cheapest). After that, it would be the valve. If it goes out once in awhile, then it could be a few things. Weak pilot safety in valve(have to replace valve), wind conditions, etc…

james taylor on Thu, 3rd Dec 2009 10:12 pm

Ii have an intertherm furnace in my mobile home and the pilot will not stay on

thomas ortlieb on Fri, 4th Dec 2009 1:49 am

hi all
i have 85 winnabaggo lesharo. the heating unit is a suburbian. on the area of the lp tank there is about 7 or 3/4 of a tank of lp in there. there is also a gage in the same area well the same gage that says i have the same amount of water. i just bought this in may of this year thinking my wife and i would spend the rest of our lives traveling, we are retired. unfortunetly she passed in august. sadest day of my life!!! ok enough about me. in the summer i checked out the heating and stove and both were working fine . i again tryed it out in september. working just great. this past saturday i went to the mountains w/some old freinds. pulled in about 3:30 pm (we live in pittsburgh, pa. it was about 50 outside but i thought im better check the heater again… worked fine. great news cause i new it was going to get cold that night we had pleanty of gas or lp. about 8:00pm we tryed to get the furnace working and all the electrical equipment worked fine but i got no heat what so ever. went outside to find that i now had no lp gas. grrrr.. i just checked it hours before. but nothing it was about freezing that night .we all bundled up in double sleeping bags and we made it thru the night. about noon it started warming up. so i went outside to check to see if we had lp gas!!! and we did. fired up the furnace , the stove burners. ohh yea we were in biziness again. about 7:00pm the temp droped again ,cold cold… the heater would not work again. stove either. my question is !!! is there anyway the lp gas could have frozen. this was a rv i bought in florida and i never filled the lp tank seeing that it had sooo much in it. dumbfounded and confused. my kids and i like to get away evey so often,,, well not exactly kids they are in there very late teens and one is in iraq. he is coming home for the holidays and i would like to take him away from all the insanity he has had to deal with. going rving is just the way to do it but lets face it w/no heat, it wouldn’t happen. any help or info would be much appreshated

respectfully
tom o
thank you in advance for any input you can give

Vikki on Fri, 4th Dec 2009 10:55 pm

Hi. I need help! Heater won’t blow air up b/c thermostat isn’t working correctly. And I DON’T Have the $$$ To hire an electrician/heater man. I did play w/the circuit bored and discovered the the red wire is disconnected on the bottom. When I touch it to the “Sprialed/Coiled up” metal, the heat goes on.
Do you know where the red wire was supposed to be attached to, on both ends???

Thank you SOOOOoooo Much for your help!!!
It’s gonna be a COLD Nite!!!

Vikki

Vikki on Fri, 4th Dec 2009 10:57 pm

Sorry! Me again. Guess it’d help to tell you what kind of thermostat it is.

Hunter Fan Company
Model # 40020A – 350

24 VAC or Millivolt Systems
1 amp maximum load

Thanks again!!!

Steve on Sun, 6th Dec 2009 8:59 am

Our forced air propane furnace system acts up from time to time (today!). The heat did not turn on at all last night (set at 64, went down to 57 by the time we woke up). I can manually raise the temperature on the lcd thermostat screen…and the furnace will wake up as in normal operation, but when it comes time to perform it doesn’t blow any air at all. It just goes back to sleep. This happens two or three times per season, and has always fixed itself. The repairman came last year, but the system was working again by the time he opened it up – said we would have to just wait until the next time it happens. Any likely causes!? I suspect it will work again before I could bring the expert in.

Rick on Wed, 9th Dec 2009 10:50 am

Hi , I have a ‘89 Lance with a Hydro Flame heater with a White-Rogers wall thermostat. It seems to work fine,,,,But It turns its self on in low temps(30-40) & runs the battery down….??

Kevin on Thu, 10th Dec 2009 11:05 am

I have had a strange situation happening to me. I have a natural gas furnace that is located in the loft of my home. My heat will run most of the time and it is fine. A couple of times the furnace has kicked off and will not kick back on. I have tried to manually override at the thermostat, but it will not override. The only way is to get my ladder and go in the loft, flip the furnace disconnect switch to the off position and then back to the on position. Then magically it fips back on. this would not be so bad but my loft is difficult to get into. This is my first year in this home so I am not sure if it has had this problem in the past….can anyone help me with this?

Huguette on Thu, 17th Dec 2009 6:58 pm

Why is my heating furnace making popping noises after the fan comes on and after it shuts off? Is there any way to correct problem? A response would be greatly appreciated.

Thank you in advance.

Have a nice day

Ed on Tue, 22nd Dec 2009 12:10 pm

I have an thermostat problem replaced old thermostat with a HoneyWell RTH111B. My wires from my furance have 4 wires a Red, White, Greem, and Blue.

As directed by the manufacture I placed the my furnances red wire at the Rc on the new thermostat which has a jumper wire connecting the Rh and Rc, I then placed the Blue wire on the new thermometers Y terminal, the Green wire on the new thermostats G terminal, and the White wire on the new thermostat W terminal.

I reset the furnance which included shutting breaker off and also shut off the switch box my furnance has and reset. I then turned the thermostat on and the set the fan to automatic the furnance kicked on and the blower started immediatley and the furnance ran for about 5-10 minutes and would never blow warm air and cut off.

Next I switched the fan setting to on and the blower run all the time with cold air. What is going on with my system it is going crazy on me. Do you have suggestons.

joe on Tue, 22nd Dec 2009 8:13 pm

I have a Duo-Therm furnace. When it comes on it blows for a little like it supose to then the gas valve clicks. Instead of the burner haveing a constint burning sound it pops and spluters then goes out. Can you help me with this problem.

john on Tue, 29th Dec 2009 2:28 pm

his is john again and the only thing i can see on my Coleman furnace is the model no it is a 7900 series by Coleman standing gas type my other coment was on nov 10 at 11:49 am can you help again thanks john from west virginia

Richard on Sun, 3rd Jan 2010 1:01 am

Hi
I have a Suburban NT-24S furnace. When i turn the thermostate on the furnace runs great. The thing gets up to tempature and the thermostate shuts the furnace down the fan runs to cool the unit and then shuts down. When the thermostate kicks back on the fan runs then you here a click but no ignition and the fan continues to run until i turn the thermostate off. Then I pulled the front cover off and turned the thermostate back on the fan will run after the delay and then you here a click and you can see the spark from the igniter but no ignition i then turned off the thermostate again waited for it to shut down. Then I waited a few minutes and then turned it on again and the furnace worked great. It always works great when it works whitch is when i first turn it on or after i turn it off and on. I have replaced the Limit Switch, sail switch and the spark electrode with flame sensor but need to find out why it works sometimes but not all the time. Any help would great. Thank you

Chris Reply:
January 3rd, 2010 at 4:40 pm

Hi Richard,
It sounds like the LP gas valve is sticking, simply because you can see the sparking, which means pretty much everything else is OK.

–Chris

Richard on Mon, 4th Jan 2010 9:38 pm

Thanks Chris for your help on my sticking LP Gas Valve. I wanted to ask if there is a way to rebuild that gas valve and if so would you know were i can get the kit to rebuild it or is the valve junk. Thank you

bob on Wed, 6th Jan 2010 1:23 pm

Hello, was wondering if you could help. I have a Suburban sf-30f. the furnace seemed to be running fine then one night it sounded like the motor was slowly coming to a stop. So I replaced the motor…which seems to be running the way it should, thinking the problem was solved i walked away. only to find that when i got home the furnace was out again. Thinking the t-stat was no good…I jumped the two blue wires right at the unit(eliminating the t stat). furnace started up and ran…i replace the t-stat. Then I waited to run a full cycle…seems the unit it shutting down because the the gas valve is not shutting off. I think the unit not shutting the gas down to allow the unit to cool once the temperature has gotten to great(in the pellenum??). so I manually jumped the t stat(2 blue wires) again…and after letting the unit get hot i disconnect the t-stat wires and the gas valve shut off and the plenum cools and the unit shuts off the way it should. is there a limit switch causing this? or module board?? any help is appreciated…bob

bob Reply:
January 7th, 2010 at 11:05 am

No need to reply, My suspicions were right. I ran the furnace again and when it was so hot that I could not keep my hand on it, I disconnected one of the wires attached to the limit switch located on the chamber. the gas valve shut off as it should(not allowing the chamber to exceed it’s allowable temp). $9.00 fix. RV place tried selling me a module for $150.00…

Harry on Wed. Jan. 6,2010 on Wed, 6th Jan 2010 2:13 pm

Chris, read all the problems people are having but did not see any like mine. I have a 2009 Laredo by Keystone. The Suburban NT30SP furnace I have works sometimes. One night last week I turned furnace on and it worked fine, until propane ran out. I switched tanks and turned thermostat off for about 20 seconds and no response from furnace, temp set at about 75 outside about 40. All it was doing when I turned it on was 1 click and 1 click when I turned it off. Second tank of propane was full. Turned stove on to bled air from lines, stove worked fine. Need your help. Thank You.

john on Sat, 9th Jan 2010 3:34 pm

hi ,i have a 1996 american caravan and i am having a problum with the Suburban furnace it is the 1 with cold air going in and hot air going out on a twin flue on the caravan wall out side ,the problum i have is i can smell gas when it fires up and i can smell gas all the time when it is runing if i take the front caver of and let the hot air flow throw the caravan it works well tho still smelling propain gas .and if i put the front caver back the the heater will shut down normal but will not egnite and the fans wil not shut down just continush runing ,tho my main consern is the gas i have cheked the gas feed to it ang is ok ,thanks john in the uk

Will on Tue, 19th Jan 2010 9:41 pm

I have a 30 ft fleetwood southwind storm and the furnace was working fine then the thing lights and after 30-40 sec. the flame kicks off then 20-30 sec it will kick on again it will do this 5-6 times then stop kicking on at all till I turn it off then back on then it just repeats on off again.whet would make this happen?

Will on Tue, 19th Jan 2010 9:53 pm

Suzy Traband on Mon, 25th Jan 2010 9:08 pm

when we put our rv away last time we used it (4 months ago) the furnace worked. It does not work now. We did leave a light on inside the coach and ran the battery down and had to charge the battery, but other than that nothing has been done. the rv stays in a heated garage. any ideas?

Richard Pohl on Thu, 28th Jan 2010 5:10 pm

I have a Suburban NT-24S furnace. I have replaced the sail switch, limit switch, gas valve and gaskets. The unit will work at least eight to nine times restarting. During that time you can hear the gas valve click and the furnace ignites and heats up. After the ninth or tenth time the unit will not click or ignite and the fan just blows until i turn the thermostate off and then on to get it to work. When the thermostate is turned on the fan starts blowing right away and then after a short time you hear the gas valve click. Sometimes when the gas valve clicks you can hear it click hard and sometimes the click is so low that you can barely hear it. Also the fan motor is starting to make wiered loud noises like a repetative noise low and high roll. I am running the furnace on the power converter whitch seems that the voltage is changing I have a reading of 11.6 to 13 volts at the plug not while the furnace is running. Can you please Help me. Thank you

Tom Hyde on Thu, 28th Jan 2010 5:11 pm

Replacement of the relay on a Atwood hydro flame furnace:::: An RV parts dealer sold me an Atwood Kit,Service,Relay #93849 to replace the Klixon relay #31017 on my Atwood furnace in the motorhome. I can NOT get it to work. My question: Am I correct or is there something that I can’t figure out?

april parcel on Sat, 30th Jan 2010 2:47 pm

my Coleman evcon furnace has a red light that flashes 4 times what does that mean

Pete on Wed, 3rd Feb 2010 12:26 am

My freind has a Nordyne forst air heater.Its in a modualar home,The pilit light wont light.Its electrical.

mark on Wed, 3rd Feb 2010 1:00 pm

hey,i need some information,on my 2008 puma,i for got to claen the snow away
from the out side vent,it back fired 2 times can you tell were the reset is or do i have to take it in and get fixed.

tank you.

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