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