If your RV refrigerator is not cooling and has that tell-tale yellow residue or ammonia smell it is time to replace the Dometic or Norcold refrigeration cooling unit. Our remanufactured refrigerator cooling units are rebuilt with heavier wall seamless tubing and a boiler design that won’t fail.
Fridge Defend monitors the boiler to ensure that it stays at its normal temperature. This prevents your fridge from overheating preventing damage to the unit and possible failure.
Refrigerators
A refrigerator is a very popular piece of equipment in RVs and it’s one of the most used appliances in the kitchen. Refrigerators are made to keep food and drinks cold so they last longer before they spoil.
RV fridges are designed with gas absorption systems instead of a compressor, which makes them different from home refrigerators. In an absorption refrigerator heat from the electric heating element or LP gas flame heats the working fluid, turning it into a gas and leaving water behind as a liquid.
Air is blown from the freezer compartment down to the refrigerator compartment through small openings at the back of each compartment. Check these to make sure they’re not plugged or blocked by spillage, dirt, etc. Also, check the fans to make sure they’re running. If not, they may need to be replaced. Adding a vent fan to the refrigerator is recommended for better cooling and venting. It will help the refrigerator run more efficiently and prevent ice build up on the fins.
Freezers
A domestic freezer is a refrigerator that maintains a freezing temperature. Freezers may be separate compartments within a refrigerator, or they can be standalone appliances. Regardless of their configuration, all freezers operate by using vapor compression to keep foods at a sub-freezing temperature.
A common place to install a domestic freezer is in a garage, which allows the appliance to be out of sight and out of mind when it’s not being used. However, a garage is usually unheated and can have large temperature fluctuations, which can be hard on a freezer.
The thermistor clips onto the fins of the cooling unit and communicates temperature changes to the fridge circuit board. When the thermistor goes bad it can cause over-cooling and corrosion. To fix this you need to remove the old thermistor and reinstall a new one. You may also want to add an internal fin fan to help the freezer perform better.
Condensers
The cooling unit (or condenser) is the component that takes the hot vapor refrigerant from the compressor and turns it back into a liquid state. It does this by using a process of heat transfer and compression. It also uses a fan to blow air over the coils and dissipate the heat that is being transferred from the refrigerant.
This is done in both air-cooled and water cooled condensers, but the water cooled types are much more complex to design and build. They consist of an outer shell with tubes inside, through which the cooled water flows. The tubes are insulated from each other with a thermally conductive mastic.
If this mastic is misapplied during the assembly process or damaged, a lot of moisture can get into the cooling unit, which will cause it to fail from the inside out. In addition to this a motorized fan is used to pull cooling air in through the bottom and out through the top venting. This is to prevent ice buildup on the refrigerant fins.
Fans
Fans are used in ventilation and air conditioning, helping to renew indoor air replacing stale air and increasing air circulation. They are powered by electricity generated from chemical reactions that slow down at cool temperatures. To perform a fair test, we will allow the fan to reach a cool temperature and monitor it until it seems like its output is approximately half of what it was at room temperature. There is a fan kit available from Amazon by Valterra for Norcold propane fridges that mounts inside the freezer venting hot air out the top. It is virtually silent and works well. It is more expensive than a battery-powered unit but requires little installation skill. It also does a better job of cooling than the Norcold internal fan which only cools the gas absorption system.Nor cold cooling units
