Dometic RM2652 Cools on Electric but Not Propane

[11Tonka]

Our fridge operates well on mains power. On propane the freezer is fine but the refridgerator compartment will not cool to below 50 degrees. Have moved the interior temperature slider to the upper limit. Have had pilot jet and burner cleaned and serviced but no change. It appears the cool wont transfer from freezer to the fridge when on propane. Could this be a gas flow/pressure problem? Any ideas appreciated. Thanks.

 

[CharlesinGA]

Check that the chimney has not been blocked by mud wasps or insects. My travel buddy had this happen. Worked fine at home, then at Linville Falls on the Blue Ridge Parkway it would not cool. He got out his generator and hooked it up and it started cooling down again. Pics show what he found.

 

[Gary RV_Wizard]

Your fridge cooling unit isn't getting hot enough (sounds bizarre, eh?) in propane mode. That is either a burner gas jet problem or something deflecting the gas heat from the coolant boiler. Look for some obstruction between the flame and the upper plate of the burner chamber. That's where the gas flame transfers heat to the boiler. It's not an upper chimney problem because that would be common to both electric & gas, but it could be a blockage in/around the burner chamber. The burner jet can be a damaged jet, insufficient air from the intake vent, or bee nests or rust flakes in/on burner chamber.

The fridge cooling unit is a 2-stage design, with the 1st stage in the freezer and 2nd in the fridge. If the boiler doesn't get hot enough, there is little or no chill left for the second stage.

 

[Kirk]

Did you get it working right? Kind of an unusual symptom so we would like to hear more.

 

[11Tonka]

Your fridge cooling unit isn't getting hot enough (sounds bizarre, eh?) in propane mode. That is either a burner gas jet problem or something deflecting the gas heat from the coolant boiler. Look for some obstruction between the flame and the upper plate of the burner chamber. That's where the gas flame transfers heat to the boiler. It's not an upper chimney problem because that would be common to both electric & gas, but it could be a blockage in/around the burner chamber. The burner jet can be a damaged jet, insufficient air from the intake vent, or bee nests or rust flakes in/on burner chamber.

The fridge cooling unit is a 2-stage design, with the 1st stage in the freezer and 2nd in the fridge. If the boiler doesn't get hot enough, there is little or no chill left for the second stage.

Thanks for the replies. To clean an obstruction ,would a bottle/round brush bent up from the bottom work ? Also can the chimney been cleaned from top down? The burner flame seems "docile" to me, you can just hear it if you put your ear really close to the outer cover. I have had the jet out and blown air through it and cleaned the burner housing, Thanks

 

[bigbAZ]

Also check the pressure at the fridge test port, I believe most absorption fridges need 11-12" of WC.

 

[11Tonka]

Check that the chimney has not been blocked by mud wasps or insects. My travel buddy had this happen. Worked fine at home, then at Linville Falls on the Blue Ridge Parkway it would not cool. He got out his generator and hooked it up and it started cooling down again. Pics show

 

[11Tonka]

Despite having had ‘experts’ look at the issue in the past, now seems we have all missed the problem. I went in from the roof vent, cut mesh back to check baffle. Discovered fibre glass insulation actually over the top of the chimney/flue 2 layers thick. Removed this. Baffle and flue were clean anyway. Fridge now works a treat. Am assuming this insulation has been there since new as we have had the problem for many years.

 

[CharlesinGA]

Glad you discovered the problem, but you need to replace the roof vent if you cut the screen, and also install bug screens on the side vents also.

 

[Kirk]

. Discovered fibre glass insulation actually over the top of the chimney/flue 2 layers thick. Removed this. Baffle and flue were clean anyway. Fridge now works a treat.

The only thing surprising about that is the fact that it worked on electric power as that should affect all modes. But that problem taking place is not rare.

 

[boatbuilder1]

The only thing surprising about that is the fact that it worked on electric power as that should affect all modes. But that problem taking place is not rare.

Been pondering this over lunch and thought that the electric element doesn't depend on the airflow through the tube to produce its heat, where as the propane depends on airflow to support enough combustion to produce the needed amount of heat. This could have been a carbon monoxide issue if left burning long enough with the low airflow.