Dometic RM3962 reefer cools fine on elec not propane

[rattleNsmoke]

My refrigerator cools just fine when operating on 110v but when running on propane takes a long time to cool or if already chilled will warm up a good 10-15 degrees within a few hours. I've replaced the burner assy (which glows a nice blue flame). I've added a thermostatically controlled vent in the chimney to draw warm air out. I've adjusted the thermistor. I contacted Dometic's technical service hotline and they say it's 'normal'. I doubt that's true because anyone that dry camps on battery would have spoiled food and warm drinks within hours. As an example, if I have a refrigerator compartment chilled to 36 degrees on electric and switch to propane either rolling down the road or if the trailer is in my driveway, the compartment temps will rise to 46-50 degrees....or more! I've verified that with a remote indoor\outdoor digital thermometer.The old Norcold in my Jayco TT never had that problem. The boiler when running on propane is HOT to the touch. The absorber tubes are air temp or slightly warm at best. Does this indicate a blockage in the cooling unit somewhere? If a blockage is suspected, wouldn't that be the same issue even when running on 110v? I've puzzled and puzzled until my puzzler was sore.....
Any thoughts? Mike

[Bama Rambler]

I've never heard that it's normal for the fridge to warm up when running on propane. Ours runs about the same on propane or electric.

I doubt that it's a blockage in the cooling system, but it could be something wrong with the gas flue to where it's not heating the refrigerant correctly.

Have you checked the baffle in the flue tube?

[rattleNsmoke]

No, I have not done an internal inspection nor have I seen how. it's a new-er round style burner box. What's the procedure?

[Bama Rambler]

Here's a page out of the service manual for that unit. It gives you the info you need to check and clean the flue tube.

Notice what it says about a dirty flue or a cracked weld.

[rattleNsmoke]

Thanks Bama! I'll give it a try removing the baffle and cleaning out the flue. If it requires removal of my fridge....well I'll cross that bridge when I get to it.

[Bama Rambler]

Please post back and let us know what you find.

[Just the 2 of us]

This sounds like the same problem we had..... Checked everything... I, to thought that the blue flame was an indicator of proper function... not so.... If you don't hear a woooshing sound after the burner lights ( similar to hot water heater sound) then you possibly have a clogged nozzle.. Not fully clogged, but just enough to prevent full power.

[rattleNsmoke]

Originally Posted by Bama Rambler

Please post back and let us know what you find.

Ended up being a clogged flue. An air compressor and copper nozzle blew whatever was in there out and now it seems to cool just fine. Thank you for your help!
Mike

[Bama Rambler]

Glad you got it fixed and hopefully it wasn't too much of a pain to fix it.

Thanks for posting the fix. It helps people in the future.

[LSUTiger]

Rattlensmoke,

Did you have to disassemble the flue and then blow it out or did you just shoot some compressed air up into it?

[rattleNsmoke]

There were three screws to remove the igniter assy out of the way, then I used a 1/4" three foot long copper tube attached to a shop blow gun and simply fed a few inches of it up the flue and blew it out. That beat the hell out of removing the fridge into the trailer kitchen and manually pulling the baffle up and out to clean.