Dometic cube Frig. Q/A

[niftypkg]

Model #2190 installed in 1993 Sunlite Pop-up. Worked great then trouble. Flame will not stay on. Possible bad thermocouple?? Will light and stay lit for a while then goes out. What do you think? The thermostat is set Ok but is hard to turn. I am afraid to force and break it. Discussion using the 12v option:I read all the search topics. My 2 cents. It is OK to use the 12v Frig option in lieu of gas for traveling down the road but should switch to gas when stationary, camping, etc. I have generally used gas traveling.
I have seen the results of a frig flame explosion when fueling up. Burned the class A to the wheels. May never happen but... Your input.

[niftypkg]

AnEv Yes the burner does not have a separate pilot. The main flame contacts the thermocouple continuously. The problem is that starting is not consistent. I would have replaced the TC if that tiny burner screw could have been removed. It is about 1/4 inch from the plywood. Bryants and Lauralhurst give reasonable details about the thermocouple. It is not removable or easily accessible. It is 'captured' within the lower box. The nut that holds the TC in place is also not accessible without removing the burner!!!
I have already built a wind shield to stop flame blowout and I could have installed a better accessible holddown if I needed to. Thanks again.

[AnEv942]

Hmm well your not the first or last to be thwarted by 1 silly bolt. Or to discover sometimes 5 times harder to work on something in place. Your doing the hard part- from this end we can only offer suggestions-encouragement along the way..none of us skinned our knuckles once tapping the keyboard.

As I understand your refer-when burner not in cooling mode-gas is throttled back to act as pilot(no separate pilot tube). I suppose if there were restriction thru orifice, when in pilot mode, flame 'could' be just marginally engulfing thermocouple to cause intermittent flame off. Would have been nice to eliminate that possibility, but honestly not high on my suspect list.

If /when you pull & clean orifice/burner & flue down the road, Id replace the thermocouple just out of hand. Because the safety valve is the only thing on that process (pilot) that mechanically 'moves' reacts to power received, assuming its receiving consistent power, its what Id replace. But its outside, accessible could be done after reassembly. The thermostat does control the pilot/main flame gas flow-sending full flow (cooling mode) or thru bypass to limit flow (pilot mode). But I see it either working or not-only as a last resort in desperation would I replace it. It can be tested for gas flow though. My understanding is though it wouldn't be intermittent.
But theres always that everything contributes a tiny bit thing...


My last question out of curiosity, between the 2 manuals, either at Bryants or Lauralhurst (though Bryants shows it) neither give details on the thermocouple, is it removable or easily accessible or is it also 'captured' within the lower box?

[niftypkg]

AnEv I gave up. Put everything back together. When finally it stops working completely I will remove the frig to clean the orifice. Ridicules to service. Thanks for your staying with me.

[niftypkg]

yegads...impressed with YOUR staying with me!! I tried all tools in the box then had to drill a hole in the frame where the gasket is and bend a narrow screwdriver to go through the hole and bend around the frame #26. Got the burner in front of me but plate #54 that holds the burner is another hurdle. The burner has to move forward to access the orifice. I'll get back to you if successful.

[AnEv942]

yegads...Impressed with your perseverance..have a feeling this might have stopped being fun. The screw, because of access or corrosion?
If access, a small ratchet with bit, or a right angle screwdriver, either make or pick one up. The small angle wrenches with phillips come in handy. If it starts to turn stop, turn it back, then try again working it back and forth increasing the amount of travel, to ensure it doesn't seize. Corrosion a bit of direct heat-penetrating oil from the back side. As it looks like a round head, doubtful you could get pliers on it.
If you had clear space obvious grind or drilling out. It doesnt show but how is the whole burner assembly attached? Just seems if box out of the way you must be close to removing burner assy?

[niftypkg]

AnEv. Finally removed the cover to expose the everything but I can't slide out the burner tube to expose the orifice. The screw #52 is almost impossible to remove. Any suggestions?

[niftypkg]

AnEv Initially I removed the flare nut #48 thinking I would be able to slide the whole thing off. The only way to get to the burner and orifice is to remove the metal enclosure #26. ( Maybe that slides towards you.)I removed screws #52 and the box didn't move. As you can see the burner tub slides into #25, another obstacle. Looks like I need to move 29 and the flue just to get the box off. I hesitate to start tearing the whole thing apart then find the frig has to come out. Any thing to make it difficult. I will take another look and get back to you. Thanks

[AnEv942]

Oh...Im not sure, looking at the diagram it appears theres a nut holding the orifice. The other end of tubeing you removed is screwed to the orifice. I thought you loosened the burner (53/54), slide it over, remove the nut 59 holding orifice 56...


But in looking I realized all of this is inside the lower sheet metal box?...no access?

If thats the case how is one supposed to access? umm, how do you get to thermocouple? thru the lil round cover...bizzare

If all your doing is cleaning the orifice-since you have line loose and assuming you have compressed air is pour a little alcohol down tube-let it set a while, dribbling out orifice. Then blow it out throughly? And chimmny/burner area.

[niftypkg]

AnEv I removed the flare nut that connects to the solenoid. The tube that holds the orifice will not move in either direction. I'll try to disconnect the propane supply to the thermostat and try again. I will get back to you.

[AnEv942]

Because the burner tube wont slide out enough to expose the orifice?

[niftypkg]

Thanks NYCsteve. That is doable. Examined the burner enclosure and it looks like the frig has to come out to clean the orifice. (ex-NYC Tom)

[nycsteve]

Use compressed air and blow out the chiminy. Spider webs can cause your symptoms.

[niftypkg]

Dave thanks for sharing your misery. I did replace the propane regulator. I was just testing it again. After several tries it finally started. On shut off the solenoid did click. I would like to take the burner assembly apart to clean the orifice and blow out the line. Looks doable without removing the frig. How did you do it? I don't see any instructions in the manual. You must have had a Dometic with the controls in front. I owned two StarCraft pop-ups before I went to an Airstream. Now I own this TC.

[Dave_Pete]

niftypkg - I glanced through the thread. It appears you still have the problem and kind of intermittent. We had a similar problem for a couple of years on our Dometic in a Starcraft pop-up. Fridge just wouldn't cool great when it got warmer outside. The flame wasn't the steadiest. We went through all the stuff and 11" of water column, replaced the regulator, cleaned the orifice and pan etc., did book maintenance, even had a tech look it over. Still the same old problem.

In the end it turned out to be a broken plastic knob on the controls where the knob fits the steel stud. The valve on the controls wasn't landing into the exact proper position "every" time the control was moved, so it was like the gas was only partially available.

Hope you can track it down. These kind of problems are really irritating.