RV Repair: Dometic fridge, household refrigerators, exterior rust

Question
Hi,

I have a 1988 trailer with the original Dometic fridge in it (1 door with ice box). I have only used it on standard electricity and it has been working fine, but occasionally seems to cease up and no longer cools.

The coils are free of debris (except for a but of exterior rust), but when it stops cooling, everything feels quite warm, sometimes even hot to touch. If it is allowed to cool for a few hours, it will work fine after being reconnected to the electricity.

Is this simply a coolant issue? Do I just need to take it and have it recharged as it works fine most times, but lately seems to stop cooling occasionally and overheat.

Answer
Hi Collin:

The problems, you are experiencing, with your refrigerator does not sound like a problem with the internal components of the refrigeration cycle. The refrigerators that operate from either gas or electric are normally refered to as "the absorption type" meaning that the refrigerant used in them is ammonia and water, whereas the household refrigerators have a compressor and refrigerant other than ammonia. Occasionally, a leak of ammonia is detected in the sealed refrigeration circuit.  When this occurs, it will eventually quit cooling. It will not normally, work intermittently. It sounds as if you are experiencing a possible control problem.

If a leak of ammonia is ever detected, it usually cost more to try and repair system than its worth. Just for information, if necessary, a remanufactured sealed unit can be purchased from RV dealers, and Camping World. I hope your problem is just in controls.

Collin, if you are comfortable working around electricity, you may want to connect a test light, or voltage tester to the incoming wires to the heating element, which is located on side of the boiler of the refrigerator. By doing this you can determine wether or not the voltage is being shut off prematurely by the controls, therefore keeping the refrigerator from cooling. If the voltage is remaining constant for a long period of time, without shutting down, the refrigerator should remain cold. If not, cooling properly, or remaining cold, the problem may lie within the sealed refrigeration unit.

I hope this info gives you some idea where to start, with your intermittent problem with refrigerator.

If I can be of further assistance, please do not hesitate to contact me.

Regards, Larry