Forum Discussion

cpachristopher's avatar
Sep 07, 2017

Fridge cools on A/C but not on Propane - EDIT: FIXED!

Hi All, I've been several years with out a TT, but wife convinced me it was time to jump back in, and so far so good, except for the fridge.

I'm pretty handy, but I called for help on this one. The repair guy came out and was baffled.

It is a Dometic, very small, no adjustment knobs anywhere. Trailer is a 2015 model so I assume the fridge is, too.

Here's the situation:

Load fridge @ Home while plugged in to shore power. It worked reasonably well. We went camping and switched to propane. Within 24 hours it was clear that the fridge was not cooling. Fortunately we had a cooler, so it worked out.

Fast forward to the next week. I had the TT parked at home on shore power. I put a case of bottled water in it, and it brought the temp down nicely. I unplugged power and switched to gas and within 2 days, the bottles barely below ambient temp..

Service guy came out - we checked and saw flame. The cooling fins are warm. The check light is NOT on.

He poked around and scraped some soot off and said that I should try again and make sure I had flame,

So....Pre-camping last week I loaded the fridge with bottles of water again. The odd thing is that the freezer (tiny, but internal to the fridge with a fold-down door) was really cold - icing up on the floor of the fridge. However, the fridge itself was not cold. I took the door off of the freezer and left the bottles inside, and sure enough, they got nice and cold - all on A/C

So, what the heck am I missing here. It seems I have flame. The A/C power is clearly heating the ammonia enough to chill the thing. And I have a freezer but not a fridge, but only on A/C. I rarely have A/C when camping,

I'd really love to avoid buying a new fridge but that is 1/3 of the reason my wife wanted another trailer (1/3 being bed off ground, 1/3 being shower)

I'm not home else I'd get the model of fridge.

Trailer is a 2015 Coachmen 16FB

If anyone has any ideas, I'd love to hear them.
  • midnightsadie wrote:
    also it takes a good 12hrs or more to cool down these rv frig units. then load with cool or frozen goodies. my money is the burner needs a good cleaning. there not hard to do, just not much room to get it out of the hole.


    Tell me about it. I have to physically remove the screws holding the upper louvered vent and then take a putty knife and pop it off the butyl tape before I can access my flue baffle and then clean the tape off and replace it and screw down the louvered vent again. A real PITA.

    Not something that needs regular cleaning but it does need to be addressed every few years (depending on how much you run on propane).... I usually run 110 shore powered and propane when camping with no hookups. The 110 heating element isn't as efficient as the propane either. There is around a 50 degree temperature difference between the 110 heater and the propane, with propane being hotter and the hotter the boiler runs, the better the cooling is.
  • also it takes a good 12hrs or more to cool down these rv frig units. then load with cool or frozen goodies. my money is the burner needs a good cleaning. there not hard to do, just not much room to get it out of the hole.
  • The boiler has a removable baffle (the wire handle is at the top), remove it and clean off the soot. If it's missing, that is your issue, the baffle has to be there to contain the heat from the flame.

    Also, check the upper outside condenser (above the sloped tubes), is it warm, should be. The freezer cools first, then the fridge, always. You might need some auxillary fans to pull the air through the heat exchanger unit as well.

    Finally, are you running the fridge level (within a half bubble on a mechanics level)? Ammonia fridges have to run in a fairly level position to work properly.
  • I agree, check the burner. May not be a hot or big enough flame. Check the stack for obstructions. There should also be a thermocouple in the stack not sending the correct values to the refrig thermostat.
    Does the control panel have indicating lights? Some models will blink a code of the problem while on gas or electric.
    Bill
  • fire your service guy. he should have taken the burner out cleaned it. and the stack ,even though you have flame does not make it enough it should have been cleaned.those little holes get clogged easy.