Community Forums

MaxAZ · 09-06-2005, 12:49 PM

I've got a 7 year old Dometic that has never given any trouble until last weekend. We were dry camping and I was running on propane. I found that the unit would cool down fine but then would allow the temperature to rise back up to just over 40 before it would relight. Anything under 40 degrees and it just won't relight. When it does get lit after rising over 40 degrees it will cool down to just under 30 before shutting down again and setting the 'check' light on the front panel. It made no difference whether the button switch was set to propane only or auto. Is this a thermo coupler problem or something?

MaxAZ · 09-06-2005, 12:49 PM

I've got a 7 year old Dometic that has never given any trouble until last weekend. We were dry camping and I was running on propane. I found that the unit would cool down fine but then would allow the temperature to rise back up to just over 40 before it would relight. Anything under 40 degrees and it just won't relight. When it does get lit after rising over 40 degrees it will cool down to just under 30 before shutting down again and setting the 'check' light on the front panel. It made no difference whether the button switch was set to propane only or auto. Is this a thermo coupler problem or something?

MaxAZ · 09-07-2005, 05:01 PM

Nobody has any ideas??

rehcuobbob · 09-08-2005, 06:59 AM

40 degrees for it to click on sounds right to me!!!

Bob

charliez · 09-08-2005, 07:32 AM

Remember your fridge depends on a good 12 volt supply from the house batteries for it's controls, even when running on propane. A weak/drained battery will make any fridge act up.

MaxAZ · 09-08-2005, 09:05 AM

At 40 degrees it will restart but only if I reset it by turning it off to clear the check light and then turn it back on. I am having some battery problems but this issue was ongoing even with my generator running to supply power to the RV. Plenty of juice converted to 12V that way so I wouldn't think power would be a problem.
I didn't realize there was an appliance forum, I'll go ahead and request this be moved there. Thanks.

Bruce, wife, & pet rabbit Jett · 09-08-2005, 10:18 AM

What happens whrn the frige in running in AC mode (when the gerneator is on)? If the problem goes away, then it's the propane side that's at fault. In any case, it's time for some troubleshooting. Lots of guides on the Internet. Here is one:
http://www.rverscorner.com/articles/refer.html

Good Luck!

Bruce

MaxAZ · 09-08-2005, 12:19 PM

I've been looking and apparently I need to start with inspecting the flute for debris and generally clean the burner and thermocoupler.
Guess I'll have to take a closer look at removing some of the panels because when I was inspecting previously, I didn't see any easy way to remove any of the panels. It looked like it was basically one unit.
I have been able to peak in there though and the flame does burn a nice deep blue, couldn't tell if there was any yellow at the end though.

MaxAZ · 09-08-2005, 12:24 PM

Oh yeah, when running witht the generator, I was still running it off propane because my 1000i Honda is only good for powering the converter which then makes the 12V DC. I'm going to try and remember to turn the fridge on using 110 tonight and test it. I think it will work though because I wasn't aware of any problems last week when I was pre-cooling the fridge to prepare for the trip. When I switched it off that to propane to hit the road I had a harder than normal time getting it to light. Normally it takes some time to purge the lines of air even with a stove burner on and it may take cycling the power button several times over a few minutes to get it lit but this last time it never lit until I was just about to give up on it.

RV Wizard · 09-08-2005, 11:15 PM

MAx, if the check light comes on that means that it tried to ignite the burner but failed after a certain number of tries by the control board. Some boards have only 1 try others have 2 or 3. After this has tried and does not ignite the check light comes on and you must turn off the ref. and back on and it will retry again. How long has it been since it has been cleaned and serviced? I agree with you that cleaning the flue is probably needed You will need to remove the ref. from it's hole to clean it properly. You need to remove the baffle (hangs on rod from top of flue)out of the flue clean it and the flue (with long tube brush) and then reinstall. Clean the burner and ignitor/sensor. CLean the nozzle with alcohol and compressed air but do not insert anything into the small orfice. Let us know the results after cleaning.

MaxAZ · 09-09-2005, 09:44 AM

Last night when I got home from work, I went to the camper and turned it on 'auto' to run on 110V. I checked it this morning and it was down under 40. The flue around the electric heat element was hot so everything seems to be working well on 110V. Next I turned on the propane tanks and lit a burner to purge some air. It took 3 attempts to light the propane burner for the refrigerator which is about normal as well. After running errands for about an hour I went back and checked the unit again and it was still working normally and the temperature had dropped to 35. Right now the camper is still plugged into an AC outlet with the battery switched to off so the frig is using the converter to supply 12V DC and propane is providing the heat source for the frig. I'll check the temperature again in a few hours when I get home and if it runs good all night, I'll pull the plug on the camper AC and run off the battery. Maybe that will isolate it.
I also pulled the model number this morning, it's a Dometic RM2652 and the igniter will spark at least a 1/2 dozen times when attempting to light the burner.
I also took a quick look at the battery connections this morning since I had recently installed it. The black cable is positive and the white cable is negative. Pretty sure that's normal.

MaxAZ · 09-12-2005, 09:19 AM

This thing still shuts down when it gets cooled down. I think it can't manage the lower burner flame and then shuts down the gas.
Saturday morning I managed to get the burner cover plate off and on inspection I found that the sensor probe had a build up of carbon on the end so I cleaned that off and blew out the burner with compressed air. The fridge ran all day with no problems but the next morning it was off again. While running, the burner flame looks very clean and blue. There's no popping and it's very consistant. I pulled the orifice/jet and inspected it and found it to be very clean, perfectly round hole. Next I pulled the top vent off and took a look down the back side from the top. Everything was clean, except a little dusty but no obstructions or anything. Finally I pulled the entire burner assembly so I could look up the flue at the baffle. Using a mirror, I was able to inspect the baffle from the bottom and found a little carbon build up at the very end of the baffle but looking past that, it's very clean with no discoloring or build up of any time. Looks a lot like an auger. I managed to flake off most of the carbon on the bottom, but it's so minimal that I don't think it's a problem anyhow since it doesn't create any obstruction at all. So now I'm kind of stuck, what else could it be. Like I said, it works very well when the burner is on high flame but I believe it goes out when it goes to the lower 'maintain temp' level of flame. Could it be that the sensor can't sense the flame when it goes to low?

YosemiteBobR · 09-17-2005, 06:04 PM

MaxAZ, I dont' know what model you have but mine has an AES mode which is automatic. It would go to check whenever I was in the mode. In manual mode it works fine. Ended up to be the board, switched it out for a dinosour board. Try this link and check it out again,

http://www.rvcool.com/

MaxAZ · 09-19-2005, 12:21 PM

BobR,
My model is a Dometic RM2652. I did try operating the unit in both manual and automatic modes and the only time I have a problem is on propane. I went to the link you provided and didn't see anything new there but I did email them with a description of my problem to see if they had any other ideas.
I wasn't able to do any troubleshooting on this unit over the weekend because of a family wedding and lots of visiting relatives but I'm hoping some time during this week I can get in and do some voltage tests. I want to make sure my power converter is working properly. I've recently had battery problems and I'm stating to think maybe the refrigerator problem is only an electrical problem.