Forum Discussion

Chuck_Sorensen's avatar
Sep 18, 2014

A few Dometic RM 8505 Refrigerator observations and opinions

Absorption refrigerators have been improved in the last few years. The 8505 Operating Instructions make no mention of having the refrigerator level during use. The warranty does not require level operation. The refrigerator works best when level and Dometic wants us to try it level before calling them for help with problems.

During a failure to cool using propane, the 12 vdc mode worked great while driving until we could obtain an ice chest. I think that the 12 volt mode is now getting a bum rap. (The refrigerator propane valve was our problem.)

While trouble shooting my cooling problem, one Dometic failure pointed out in their service manuals that got my attention was the burner flue tube becoming unwelded from the boiler. Burner works great, but no heat is transferred to the boiler.

I drive with the refrigerator on propane when a cluster of vehicle stops is anticipated.

I drive with the refrigerator on propane when charging the coach battery is a priority.

Refrigerator temperature seems to increase a couple of degrees over the stationary temperature when driving with the refrigerator on propane. I have not checked 12 volt operation temperature differences.

When all of its parts are working, this refrigerator performs better than expected; as during occasional unlevel and higher elevation operation. When you consider that the closed cooling system contains water, ammonia, hydrogen gas, and a corrosion inhibitor that you add heat, gravity, 12 vdc control, and ambient air to, and then it can make ice cubes; it is like magic.

Chuck Sorensen
Buellton, California
2012 PW Excel TS
  • The following is directly from Owners Manual for the Dometic RMD8505

    Please observe the following particular conditions for storing food in a refrigerator that is built into a vehicle:

    *Use of the refrigerator during travel with the
    power supply of 12V DC

    Under these particular conditions the refrigerator cannot guarantee reaching the temperature needed for perishables


    Reason no guarantee is due to small size of DC heating element. It is intended for use in 'maintaining' temps while in transit.
  • My 8330 seems to run fine in DC mode when traveling. I drove down to florida and back this summer without issue. Key is starting with a cold fridge.
  • The DC part has been the weak link of our previous two Dometic 3-way refrigerators. It simply does not cool as well as AC or propane. It will barely maintain temperature and if you start using your refrigerator and opening the door a lot you will most likely end up over 40F fast while underway. That happens if you stock your refrigerator with cold liquid refreshments and cold snacks and grab them out while driving. That happens when you have a passenger partner that can do that. And that's why the temptation to run on propane while driving grows on you. A 3.8 cf refrigerator can lose its cooling fast.
  • i read reviews of the Dometic 8 refrigerators. they are superior to the previous versions.