The cooling units in dometic and Norcold refrigerators are driven by the distillation process; the working fluid, ammonia is separated from the water by heat (electric heating elements or LP gas flame). When the ammonia boils it turns to gas, leaving the water as a liquid. This is why controlling boiler temperature is so important – too much water or too little ammonia and the refrigerator will rust from the inside.
The number one reason cooling units fail is because they rust, leaking ammonia. But other problems can also ruin a refrigerator, for example, a bad seal, the wrong size fan or even improper mounting.
JC Refrigeration is now offering an upgraded cooling unit for the Norcold fridges that is the same price as replacing the original ammonia based one. The new remanufactured cooling unit has the same capacity as the old ammonia based one but is bigger to handle the increased demand on the refrigeration system. This results in a better colder fridge.
Another benefit of the upgrade is that it keeps air out of the evaporator. The original Norcold cooling units are small, forcing the evaporator to work harder. Over time this can cause crystals to form in the evaporator pipe and it will eventually rust out. This rust can leak the ammonia into your RV, burning and destroying everything in the fridge.
When installing the new cooling unit, it is important to lay it down on the evaporator pocket and trim any foam around the edge of the pocket. This allows you and your helper to get the evaporator pockets to seat properly into the refrigerator. It is also a good opportunity to check that the weak solution cavity in the boiler assembly is positioned correctly. norcold cooling units