The cooling unit is most likely not in need of replacement if the unit works on one heat source but not the other. The cooling unit however might be showing the first signs of trouble.
Is the refrigerator level? Yes - continue
Is anything blocking the refrigerators vents? If no continue
Are the gasket rubbers around the door/s damaged or misaligned? If yes realign or repair - if no continue
Is the gas flame on and is it as large as normal? The burneror gas jet might need to be cleaned or the gas regulator might be out of adjustment. If so the unit will need repairs - click here for Dometic or Norcold manuals for the more technically inclined - or click here for factory repairs etc. - if no continue
Is there an ammonia smell coming from inside the refrigerator? If yes and cleaners or disinfectants haven't been used recently (they can smell like ammonia) then chances are that the cooling unit is leaking and will need replacingclick here - if no continue
Is there is a yellowish powder or stain on or near the refrigerator cooling unit? If yes then refrigerant is leaking from the cooling unit and chances are will need replacing click here.
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The manual states it will produce between 14 to 30 millivolts DC in normal operation. It says to connect to a safety valve and apply flame for e minutes while depressing the safety valve. Remove flame and release safety valve. The safety valve should hold for at least 30 seconds. If it does not hold for 30 seconds or more, replace the thermocouple.
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you can also try cleaning the burner and valve.
The first steps to undertake are to clean the flue, the burner tube and the orifice. Remove the rear access cover on the outside of the coach. On the right lower side of the refrigerator, there is a tin cover which you remove to access the burner. The flue, or chimney, is located right above the burner flame. Often, a flakey rust colored residue falls from the flue and clogs up the burner ( this is a result of combustion and is a normal occurrence). This residue will also interfere with the sensor probe and flame outage will result.
Use compressed air to blow out the flue and the surrounding area. Remove the screw holding the small tab that holds the thermocouple in place. The thermocouple is a narrow rod with the end that sticks into the burner flame. Pull out the thermocouple to access the two screws that hold the burner assembly in place.
Remove the burner tube and soak it in alcohol for 15 minutes, then let it air dry.
The orifice is located just to the left of the burner tube and is a brass colored nut with a very tiny hole in it. Remove this a let it soak in alcohol also. Do not probe or poke anything into the orifice to clean it - this will drastically affect the flame characteristics and will render the orifice useless. Once soaked and dried, you should be able to hold it up to a light source and see the light shining through the orifice opening.
Re assemble every thing and light the burner flame. A normal flame will be a "hard blue" color with no yellow tip, and will emit a slight roaring sound.
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its quite possible that there is Air in the gas pipe.Switch device off and on again 3-4 times to remove air from the gas pipe.Briefly switch the refrigerator off and then on again using main switch. To remove air from the gas pipes, repeat this procedure 3-4 times.Also check both the valves.the gas bottle valve and on board shut off valve.if any of the valve is getting closed, the unit will stop working on gas.Both valve should be open.Also clean the thermostat and check.if still the same problem, then replace the thermostat. -------------- If you remove the outside cover from the RV behind the refrigerator you can see or hear the flame when it's running. Turn the thermostat to a warmer setting than go outside and see if the flame goes out or reverts to the pilot light (older units only). If the flame remains running full blast, that's where all your propane is going. I suggest getting the refrigerator repaired .
If the unit just won't remain running on propane, you may have a defect in the safety circuit which detects the flame.The circuit board needs to be checked.-
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Make sure everything propane is turned off in the RV. Go out and disconnect the propane tanks making sure the valves are turned off, reconnect the tanks and open the valves on them, then go back inside and light the propane cooktop burners to get all the air out of the system; you should have a good flame on the burners now. Now try restarting the fridge again. If this doesn't cure the fridge the you might have a thermocouple issue or a controller issue.
Did you recently have the propane shut off? If so, turn on the range for a few minutes to purge all the air out of the lines. Then try the fridge again
