Dometic two-way refridgerator

[beatrice]

When 120 volt is disconnected fridge will automatically switch to propane.  After only 45 seconds the propane gas control will close, can hear it click off.  Do you have any suggestions for us to try.  The controls are all 12 volt.  This is in a 1998 Fleetwood Southwind.
When resetting it reacts the same way.
Thanks

 

[Woody]

Are you sure the gas control is closing off ??
I ask this because my Pace Arrow has a 3 yr. old 2 way Dometic and I cannot hear anything when it goes from 120v to gas. The little red light for gas will light but that is the only indication. All the propane does is power a very small pilot light, not a burner which would make noise.

Woody

 

[Karl]

I'm not sure I'm understanding you problem. Does the gas (propane) flow to the fridge stop and not cool it? Do other propane applinaces work normally (strove, furnaces)? FYI - a refrigerator running on propane will make almost no sound; it's a really small flame -  not like that of a water heater which you can clearly hear.   

More info, please.   

 

[John From Detroit]

Most propane powered stuff has some kind of flame sensor to determine if the flame is flame or just gas

Flame good, just gas bad, thus it's a safety issue (Very very very very very bad in fact)

Now, observe the operation... (Look as well as listen) do you SEE flame? If not, then do you SMELL gas (NOTE, do not smoke, have open flames of any kind, or even use a flashlight when doing this) or hear gas flow.

If smell or hear gas flow.. And no flame, ignition issue

If see flame, but it cuts out, sensor issue

In both cases possible control board issue

Hire a professional if you are not comfortable working on this stuff

I don't much like to work on Propane stuff if there is another alternative

 

[Gary RV_Wizard]

In all probability the flame sensor is not detecting the presence of a lit flame and is shutting off the propane as a safety measure (as John describes).  The most likely reason is either the propane burner is not lighting or it lights but the sesnor fails to detect it. It's not uncommon for the burner tube to get clogged with rust chips, spider webs, wasp nests or some such and prevent lighting.  You could try vacuuming the burner tube for starters - sometimes it helps.  Next most likely is  a misadjusted igniter, so the spark is not igniting the flame. Then comes a failing flame sensor, i..e the burner lights but the detector doesn't report it as lit. You should be able to see the flame in the tube when it switches to propane, before the shut-off occurs. If you see the flame, then the flame sesnsor is probably bad. If you don't see a flame light, its probably the burner tube (clog), igniter or ignition circuit.

 

[beatrice]

Thank you for all the good input.  All other gas appliances work well.  Fridge:  You hear the igniter and see the pilot light and hear the flame in approximately 45 seconds you hear a click and the flame and pilot shuts down. 
Does this narrow it down?

 

[Karl]

Beatrice,

As both John and Gary have mentioned, the most probable causes now are the flame sensor and/or the control board. The clicking sound is the gas valve shutting back off because the flame was not sensed. Could be either one, but if it's the original control board, that would be my guess. They are known to fail more often than the sensor itself.

 

[beatrice]

Hi:  Hope you read this - we finally got the refrigerator fixed.  Reading, reading and more reading brought us to buy a new board, that however made a difference (small) but not fixed.  Then he installed a thermocouple and that was the answer.  He didn't want to take it to the dealer (too expensive).  We are delighted with your responses and help - thank you.
Beatrice

 

[Ron]

Thanks for the feedback.  Glad to hear you were able to get it fixed.

 

[bajawinters]

Sure glad you guys run this forum.  We just renovated a 1979 Lance truck camper to rent out at a surf camp in Baja Mexico and it has a Dometic two way.  It works on electric yet we would prefer to run it on gas.  We haven't had a chance to spark it up, but when we do threads like this will sure come in handy.

 

[John From Detroit]

Well B, and B, Glad we could help solve the existing problem and prepare for new ones.

One more suggestion,  Pay attention to the maintance, clean the sensor and burner and flue from time to time as suggested in the owner's manual.  I was chatting with a technician while he was workign on someone else's rig and his diagnosis was "lack of routine maintance"

 

[bajawinters]

We're going to wait until the camper is off the truck in it's permanent resting spot before we look into the propane part of the fridge.  Thanks for the suggestion on the maintenance.  My son wanted to just spark it up and see if it worked.  It's probably a better idea to clean it up before, and check the flame.  Now I have some knowledgeable ammo to throw into our debate.

 

[TBG8503]

Where is the flame located? 

 

[CoachPotato]

Replacing the board is an expensive fix. Sometimes it's just the contacts.

I had to come home on AC my last trip because the propane quit working. I pulled the board, cleaned it up, sanded the contacts where it plugs in and - voila! - it works fine now. And it's the same old board. My son, a former Navy electronics tech told me that one.

I just hope it stays fixed.

If you have to buy the board, shop online as the prices vary quite a lot. The local dealers should wear a mask! 

 

[Karl]

It's unlikely that you can 'see' the flame; it's located inside the chimney flue area. You should feel for heat on the outside of the chimney area (careful; it might be hot!) near the bottom. Also, 'sanding' contacts can do more harm than good. If you want to clean them (not a bad idea), use a spray contact cleaner or a pencil eraser - never sandpaper!!!

A board replacement is about $100.