Refrigerator: Replacing Cooling Unit

February 26, 2020
By Barry Beam 8/20/08

Things I found to be problems causing the temperature to not be cold enough:

  1. The temperature should be 0-5 degrees in Freezer & 38 in refer.
  2. Check gasket around doors for a good seal.
  3. The coach was level but the refrigerator was not level to the coaching front to back. I had to have refrigerator removed & add a 1/8″ shim under the right side to make it level.
  4. Make sure aluminum paper attached to the cooling unit is attached with thermal mastic & has no air leaks.
  5. Before putting the refrigerator back in making sure the cabinet is sealed all around with Styrofoam and tape and leave no air gaps.
  6. There should be thermal mastic all around the cooling coil before attaching the fins to the rear of the refrigerator. I found one-half of fins were colder than the other half because there was not enough thermal mastic on one side to conduct cold.
  7. Raising the inside temperature probe on fins “UP” will lower temperature (heat rises). Under normal outside temperatures, I leave the probe in the center of fins.
  8. Good venting is necessary & a rear fan may assist in that. Mine appears to be in the wrong location & may have to be moved higher.
  9. High outside temperature and humidity made it difficult to keep inside temp down no matter what else I did.

Changing a Cooling Unit after Hot Wiring it to determine it was faulty

Shaving expanding foam to fit flush. The key to a successful cooling unit installation is a snug fit between the cooling unit head (foam block) and the box, with the head all the way into the cavity of the refrigerator and no air leaks.
The cooling unit needs to fit all the way into the refrigerator cavity and not be held back by any part of the foam block. Adding thermal mastic all around it before reinstalling to get a good airtight seal.
You can see there was not enough thermal mastic around the cooling coil to eliminate any gap between the coil and the fins.
Removing Ice Maker 
You can see the paper attached to the cooling unit was loose causing air leaks & needed to be secured with thermal mastic
Disconnect Rear Wiring 
Install 110 VAC Heating Elements 
The baffle is a spiral device that hangs down inside the chimney to slow the heat rise from the propane burner.
Attach Rear Fan Thermostat to Fins
The sides of the foam block need to be sealed with premium or thermal mastic to prevent air leaks. Other parts of the cooling unit give off heat and the slightest air gap around the foam block will allow this heat into the refrigerator
Screw new cooling unit onto Box and put thermal mastic all-around the aluminum paper so there is no air leak.
Install Double Cooling Fan 
Rewire rear of Refrigerator. Install all the peripherals that you had removed earlier (heat elements, baffle, burners etc.)
Before reinstalling Fin Unit in Refrigerator , apply about a 3/8″ bead of thermal mastic along the entire length of the evaporator coil
1″ Gap all-around box needed to be sealed with Styrofoam & tape before putting refrigerator back in.
The freezer coil protrudes horizontally into the freezer instead of being embedded vertically into the foam. The freezer coil needs to be perpendicular to the cooling unit body. Apply thermal mastic on top of the coil before replacing the plate.