How to Replace a Defrost Sensor

Side-by-Side Refrigerator

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.

Use this repair procedure on Kenmore, Whirlpool, KitchenAid, Maytag, Amana, GE, Frigidaire, Electrolux, Bosch and Samsung side-by-side refrigerators.

Tools required

1/4-inch nut driver


Work gloves

Wire stripper

Repair difficulty:


Time required:

45 minutes or less


01. Disconnect the electrical power
Safely store any food that could deteriorate while the refrigerator is shut off. Then unplug the refrigerator or shut off the circuit breaker for the refrigerator.

02. 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.

  • Remove the freezer basket

  • Remove the freezer shelf supports.

03. 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.

  • Remove the evaporator panel screws.

  • Remove the evaporator panel.

04. 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.

  • Release the defrost sensor clip.

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

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

06. 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.

07. 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 the harness up to keep them out of the way.

08. 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.

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

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