How to Replace a Defrost Sensor in a Side-by-Side Refrigerator

 

bi metal PD_0046_106_4387503

This refrigerator repair guide gives step-by-step instructions for replacing the defrost sensor in a side-by-side refrigerator. The defrost sensor—also called a defrost bi-metal thermostat—shuts off the defrost heater if the heater gets hot enough to damage the evaporator. If the defrost sensor fails, the heating element doesn't turn on, and frost builds up on the evaporator resulting in warm temperatures in the refrigerator. If your defrost sensor is defective, replace it with the manufacturer-approved replacement part.

Repair difficulty:
     
Time required:

Less than 45 min.

Parts Required

  • Defrost sensor
  • Cable ties
  • Silicone sealant
  • Wire nuts

For manuals, repair guides, and specific part recommendations, enter your model number.

Tools Required

  • 1/4" nut driver
  • Screwdriver
  • Work gloves
  • Wire stripper

Before you begin

Wear work gloves to protect your hands. Safely store any food that could deteriorate while the refrigerator is shut off.

Instructions

 Warning: Undertaking repairs to appliances can be hazardous. Use the proper tools and safety equipment noted in the guide and follow all instructions. Do not proceed until you are confident that you understand all of the steps and are capable of completing the repair. Some repairs should only be performed by a qualified technician.

Step 1: Disconnect the electrical power

Unplug the refrigerator or shut off the circuit breaker for the refrigerator.

Step 2: Remove shelf supports from the freezer

Remove the shelves and baskets from the freezer compartment. Remove the screws from the shelf supports on the right interior wall of the freezer and pull the supports out.

 Tip: If necessary, refer to your owner's manual for guidance in removing baskets and shelves from the freezer.

Step 3: Remove the back panel

Remove the mounting screws that secure the inside back panel of the freezer. Pull the bottom of the panel outward slightly to release it.

Step 4: Unclamp the defrost sensor from the evaporator

Note the positioning of the defrost sensor. Release the metal clip that holds the defrost sensor to the refrigerant line located above the evaporator.

 Tip: Take a digital photo of the defrost sensor to help you position the replacement correctly.

Step 5: Remove the defrost sensor

Cut the brown and pink wires near the defrost sensor and pull the defrost sensor out of the freezer.

Step 6: Install the new defrost sensor

Use a wire stripper to remove the insulation from the ends of the pink wire and brown wire on the new sensor. Strip the ends of the pink wire and brown wire in the harness above the evaporator. Use wire nuts to connect the matching wires. 

To keep the connection dry, squeeze silicone sealant into the open ends of the wire nuts.

 

Step 7: Clip the defrost sensor onto the refrigerant line

Clip the new defrost sensor onto the refrigerant line above the evaporator. Position it in the same manner as the original defrost sensor. 

Without disturbing the sealant on the wire nuts, push the wires above the evaporator. Use a cable tie to fasten the wires to other wires in the harness to keep them out of the way.

Step 8: Reinstall the back panel

Reinstall the back panel and replace the mounting screws. Over tightening the screws can crack the freezer liner or the mounting rails. Rotate the screws until they stop and then snug them up with a final twist. Reinstall the baskets and shelves. 

Step 9: Restore electrical power

Plug in the refrigerator or turn on the house circuit breaker to restore power.