Fridge has intermittant operation on Propane

[BEBOP]

HI ALL,
MY fridge is dometic and 2 years old with very little use, because the Rexhall has lived in the repair shops for it's first two years.
we just made the first trip to Canada and back from Central CALIF. and the fridge works fine on shore power but intermittantly on propane.
I was traveling long days so I would put it on propane as we were leaving in the morning and some days it would work all day and others it would not work at all.
Any thoughts on this before I dig into it? I did renew the warranty but have no idea where I might need to take it in San JOse, CA.
Hope to get some good advice from anyone here and thanks in advance,
Bebop

[BEBOP]

HI ALL,
MY fridge is dometic and 2 years old with very little use, because the Rexhall has lived in the repair shops for it's first two years.
we just made the first trip to Canada and back from Central CALIF. and the fridge works fine on shore power but intermittantly on propane.
I was traveling long days so I would put it on propane as we were leaving in the morning and some days it would work all day and others it would not work at all.
Any thoughts on this before I dig into it? I did renew the warranty but have no idea where I might need to take it in San JOse, CA.
Hope to get some good advice from anyone here and thanks in advance,
Bebop

[Bob (WA0MQE)]

I had a similar problem this last week with our Dometic. Worked okay on electric but not propane. The problem was it wouldn't light. While checking it the spark gap would fire, could hear as well as see it. It was getting gas (propane) but just didn't seem to want to light.

I took the igniter out and cleaned it real good with emory cloth, and likewise the gas burner tube. I also cleaned the temperature probe. There was a lot of crud on these parts. I checked for +12 Volts at the circuit board and made sure fuses were okay. I also removed each wire connector to the circuit board and re-inserted to clean any corrosion. (Be sure and disconnect +12 volts prior to doing this.)

None of this seemed to help, so finally I manually lit the burner by turning the fridge on and holding a butane lighter at the gas burner tube flame area. It lit just fine and has worked perfectly ever since. Not sure what the problem was, but it seems to be okay now. Might have been a combination of crud and/or improper gas flow.

[BEBOP]

HI BOB,
thanks for your impute. what seems odd to me is that as the fridge would not light and was off all day while driving and would not light at the end of the day, but........
I would then plug into shore power and fire on the fridge on ac for the night and the next morning while the fridge had the heat in it from the ac the gas side would work all that day. It seems that it needs to be preheated for the gas to work. I just don't understant that. I don't think the thermo couple would cause that. Usually it either works or not but then again maybe with the AC heat in the thermocouple it would work.
Does anyone else have any thoughts on this problem.
thanks for any help, and thanks to Bob for your reply,
Bebop

[RV Wizard]

Try to make it a practice to lite the stove top before turning ref. on gas mode. This will help bleed air out of the line when it has been stored. Even then you may have to turn it on and off several times to get the air out of the line feeding the ref. For those that are having a hard time lighting when gas is present I would recommend you have the lp regulator gas pressure checked to be sure it is at 11" water colum. The ref. will be effected by incorrect pressure when all other appliances work ok with this pressure being slightly off. Make sure the burner and flue are properly maintained and you ahould not have much problem with it operating.

[BEBOP]

thank you for your response however:
1. I was talking about traveling every day for several days at a time, not coming out of storage when I do bleed the line first. Because we were traveling every day and hooked up to AC every night there was gas in the line because the hot water tank and stove were operating prior to or even while turning on the fridge to gas for the travel day.

2. it was turned on and off several times each time the chick light came on, until finally giving up.

3. When the fridge does light it does not have a problem and operatates all day as designed. Wouldn't this negate the need to have the regulator adjusted?

4. I have not had any maintainence done on the flu and burner as the unitis virtually unused and had never been used on gas before, other then to check it for correct operation each time it was taken out of storage, in case the gas operation might be needed. What maintainence are you suggesting.

4. I have had a lot of RV fridges since 1979 that were 2 way and 3 way and never ever had a problem through the years with any of them except the first truck camper failed from being out of level too many times while stopped. Only once did I have to have a humidity electrical switch replaced which was mailed to me under warranty and I installed it in about 2 minutes.
thanks for your help,
Bebop
Try to make it a practice to lite the stove top before turning ref. on gas mode. This will help bleed air out of the line when it has been stored. Even then you may have to turn it on and off several times to get the air out of the line feeding the ref. For those that are having a hard time lighting when gas is present I would recommend you have the lp regulator gas pressure checked to be sure it is at 11" water colum. The ref. will be effected by incorrect pressure when all other appliances work ok with this pressure being slightly off. Make sure the burner and flue are properly maintained and you ahould not have much problem with it operating.

[RV Wizard]

Bill, you may still want to have the regulator pressure checked under a load. It might be ok when ref. alone is trying to ignite but may fail if another burner is in operation at the time. CHeck the gap between the ignitor and the burner. It should be at 3/16" of an inch. On normal maintenace the burner, ignitor, orfice and flue would be cleaned and the ignitor gap checked. Make certain that all wiring is tight. On a day that it is very humid check the high tension wire to be sure it is not shorting out before it reaches the ignitor. I have found that a bad wire will, in high humidity, show itself. Good luck and let us know the outcome.

[BEBOP]

thanks Mike for your last reply.
I spoke with my all purpose shop that is also our workhorse warranty shop and they tell me they are approved for dometic warranty work also so as I renewed the warranty, I will just take it to them next time it is coming out of storage..........Providing it won't light on propane so they can trouble shoot it.
Thanks to all who replied and,
best to all,
Bebop

[Ray,IN]

Thermocouples operate on milli-volts, generated by the heat of the pilot. Any corrosion on a connetion is capable of causing intermittent operation. Is the thermocouple directly above the flame? Is it tight in the gas valve or corrosion present on the end of the connecter? A new thermocouple is around $6. I used to carry a spare for these situations.

Many shops are manufacturer approved to perfom warranty work. The catch in this is, most manufacturers require prior written authorization, this is not the same as the shop being approved to perform warranty work. Highways and many other camping magazines relate tales of woe from owners who did not read the fine print in the warranty.

[machman72]

I've got to agree with RV Wizard. Sounds like your regulator to me. I had the same problem with my Dometic. Replaced the regulator and no more problems. Regulator is easy to replace, and cheaper than a trip to the shop for an on again off again problem. That is usually when the charges rack up, trying to hunt for a problem.

[BEBOP]

thanks for your reply,
Is the regular preset and just a matter of bolting on and leak testing? What kind of a store did you buy it at and how much did it cost?
Bebop

[RV Wizard]

Bill, the lp gas regulator is located at the tank after the main valve. It should have a cover over it that would have to be removed to gain access. I would recommend a competent technician to load test and adjust your present regulator. If it can not be set to 11" wc with the water heater and stove top in use then replace it and check the new one for proper setting once installed and leak tested before operating. I have seen new ones slightly off calibration and everything works but the refrigerator. The refrigerator used such a small flame in comparison to the other appliances that it is much more critical to have the right lp pressure to creat the proper flame for the sensor to work in. GOod luck and keep us informed.

[BEBOP]

Thanks for your response Mike,
I keep coming back to the same question before planning a course of action.
Why does it work ok one day and not the next day. Why does it seem to work after it has been on electric operation for awhile. Once it is on and working it will work indefinately and maintain the proper temps in the freezer and fridge.
Does this make any sense to anyone?
Bebop

[RV Wizard]

Bill, you may be able to maintain enough cooling after the electric heaters have pulled the heat out but if the BTU of the flame is not correct you may not be able to pull it down in the lp gas mode.