How to replace the defrost bi-metal thermostat in a top-freezer refrigerator

This DIY repair guide gives step-by-step instructions on how to replace the defrost bi-metal thermostat in a top-freezer refrigerator. The defrost bi-metal thermostat shuts off the defrost heater if it gets hot enough to damage the evaporator. If the defrost bi-metal thermostat fails, the heating element doesn't turn on, and frost builds up on the evaporator. When the frost buildup is excessive, the refrigerator can't cool well. If the defrost bi-metal thermostat fails, replace it with a manufacturer-approved replacement part.

This basic repair procedure works for some Kenmore, Frigidaire, Whirlpool, KitchenAid, Maytag, Amana, GE, Samsung, Gibson, Crosley and Haier top-freezer refrigerators.

Instructions

1. Shut off the power

Move your frozen food from the freezer to the refrigerator section and then unplug the power cord from the wall outlet.

2. Remove the freezer shelf

Remove the spacer in the freezer shelf.

Push the shelf to the left to release the right side of the shelf from the holes.

Pull the shelf out of the freezer.

3. Remove the evaporator cover

Remove the mounting screws from the evaporator cover.

Pull the top of the evaporator cover down and unplug the evaporator fan wire harness.

Push the evaporator cover to the left side of the freezer and disconnect the green ground wire and the ice maker wire harness from the evaporator cover.

Pull the evaporator cover out of the freezer.

4. Pull out the defrost bi-metal thermostat and freezer wire harness

Unplug the wires from the defrost heater.

Release the defrost bi-metal thermostat and the defrost thermistor from the evaporator coils.

Unplug the freezer wire harness from the back wall and lay the freezer harness on a work table.

5. Remove the defrost bi-metal thermostat

Cut the electrical wires close to the defrost  bi-metal thermostat.

Remove the defrost bi-metal thermostat from the freezer wire harness.

6. Install the new defrost bi-metal thermostat

Strip 1/4-inch of insulation from the ends of the supply wires and new defrost bi-metal thermostat wires.

Slide the heat shrink tubes onto the new bi-metal thermostat wires.

Connect the new bi-metal thermostat wires to the supply wires using the wire connectors.

Slide the heat shrink tubes over the wire connectors.

Heat the tubes using a heat gun to seal the connections.

Tip: The defrost bi-metal kit includes the wire connectors and heat shrink tubes.

7. Reinstall the freezer wire harness

Plug the freezer wire harness into the back wall receptacle.

Attach the defrost bi-metal thermostat and defrost thermistor to the evaporator.

Connect the wires to the defrost heater.

8. Reinstall the evaporator cover

Position the evaporator cover in the freezer compartment and reconnect the ice maker wire harness and ground wire.

Push the evaporator cover to the center of the freezer compartment and reconnect the evaporator fan wire harness.

Position the evaporator cover over the evaporator and reinstall the mounting screws.

9. Reinstall the freezer shelf

Push the shelf into the mounting holes on the left side of the freezer compartment wall.

Slide the shelf to the right and reinstall the shelf spacer.

10. Restore power

Plug in the refrigerator to restore power.