Raya, There are 2 heating elements, one is a 110 volt ac element and another 12 volt dc heating element. The 12 volt element never fails, but is not very efficient for using. The 110 volt ac heating element is only powered when the refrigerator
is set to ac power. The most efficient and fastest way to cool your refrigerator
is the propane
setting. I have seen the propane
side not work on several campers also, but the main reason is dirt or spider webs inside the combustion chamber where the pilot light
is burning. If the refrigerator
runs on either 12 volt or propane, the problem has always been the 110 ac heating element. The metal cylinder pictured above is where all 3 types of heating are applied to the amonia system. The propane is just a small pilot light
under the cylinder, and most of the time there is an inspection cover that you can look into to ensure that the flame is lit. The heat just expands the amonia into gas like a compressor compresses freon in a standard residential refrigerator.
One other thing to look for on the rear of your refrigerator is the tubes or coils. There is a recall of certain models for leaking in the tubes where oil seeps out and runs down into the pilot light and burns your RV to the ground. The recall is mainly for double door models, but I always check mine for damage or leaks
. I figure if there is a problem with one model, why not others? I deal with alot of different campers and RV's and have seen many with the sides burnt out from the refrigerator defect. Most people blamed it on traveling with the propane on, or wasp nests, when in fact it was the defective Dometic refrigerators.
Does that answer your question?