The repair done on the recall was to add a piece of sheet metal heat shield between the LP gas burner and the skin of the RV, because someone thought that when the burner was on it could overheat the outer skin of the RV and cause a fire.

The actual cause of the fire was a leak in the ammonia piping. Under certain conditions anhydrous ammonia vapor can become flammable if it is in a 15 to 28 % concentration. This leak was in the area where the sleeve containing the 120 volt heating element which is welded to the chimney area of the ammonia tubing. Anhydrous ammonia is very corrosive to most metals and manafacturers use a low carbon steel and since the ammonia is mixed with water they add a chemical to the water to prevent corrosion in the steel tubing. This is evindenced by yellow deposits left after the ammonia / water mixture has leaked out.

Without doing further metalurgical testing it looks like dissimilar metals were welded together which combined with the vibrations from towing an RV eventually caused the leak. As long as the refregerator is only powered by 120 volts the only risk is enough ammonia is lost to affect the cooling capicaty of the refregerator.

In summary, don’t be fooled by thinking just because the recall repair was done on your Dometic refregerator there is no longer a fire hazard, the true root cause of the fires has not yet been addressed.