Dometic RM2551 fridge won't operate on propane

[kjmaggart]

We are new to the camping / RV world so please excuse any rookie statements I make. We love the camper but are learning there are a number of maintenance issues.

Our Dometic runs well on shore power. The bottom of the tube heats up and there's a noticable difference in temp between the top and bottom of the tube.

On LP, however, it lights with no problem and stays lit with a nice blue flame. However, the entire tube heats to the point of being very hot to the touch; no thermo difference between top and bottom.

The fridge does not cool at all when on LP. I've inspected the board and it looks good - no obvious overheating or bad connections. I've inspected the flume from the bottom. The baffle is present and I do not detect any soot or debris in the tube.

I appreciate any suggestions as to what to do next. I am mechanically inclined so not afraid to get into it deeper.

[Old-Biscuit]

Cooling Unit 'Perk Tube' is he boiler section where HEAT is transfered and boils the ammonia into hot vapor

Electric element transfers that heat via conduction....element get hots, heats the element sleeve which is welded to perk tube and heats the ammonia inside \\

Propane Flame generates heat which is absorbed by the flue baffle which then transfers the heat via radiation

Flame should just reach up inside bottom opening of flue
At top of flue should be a FLUE CAP/TOP
It slows the heat rising up from flame so baffle has opportunity to absorb the heat generated.
W/O FLUE CAP heat rises/escapes to quickly...therfore less is absorbed and trransfered to boil the ammonia

[midnightsadie]

welcome. theres some good guys on here who will chime in on your problem. and if you need pro help call a rv tech in your area, they come to you, your rv won,t sit at the dealers lot for a month before they even look at it. also the rv tech will answer question you might have. mkost are very helpful.

[DFord]

The boiler is heated from the outside with the electric heater inside a tube welded to the side. The propane flame heats inside the boiler. The normal operating temperature of the boiler should not exceed 350 degrees on either one. Unfortunately, the mfgs don't have a limit control as standard.

https://www.rvrepairclub.com/article/how-absorption-refrigeration-works/