The defrost thermostat (a bi-metal switch) prevents the defrost heater from overheating. Replacing this component is necessary if it is defective to ensure proper defrosting and avoid potential overheating issues. Here’s a step-by-step guide to replace the defrost thermostat.
Caution: Please read our safety information before attempting any testing or repairs.
Important Safety Notice: Before replacing the defrost thermostat, unplug the refrigerator to avoid an electrical shock hazard.
Tools and Materials Needed
- Screwdriver (Phillips and flat-head)
- Needle-nose pliers
- Safety gloves
- Warm, wet towel (for plastic molding removal)
- Replacement defrost thermostat
Steps to Replace the Defrost Thermostat
Step 1: Safety First
- Turn Off Power: Unplug the refrigerator to prevent any electrical shock.
- Wear Safety Gear: Wear safety gloves to protect your hands while working.
Step 2: Access the Defrost Thermostat
- Locate the Thermostat: The defrost thermostat is usually located near the defrost heater at the back of a side-by-side freezer or under the floor of a top freezer.
- Remove Obstructions: Empty the freezer, and remove the freezer shelves, icemaker, and any other obstructions.
- Remove the Access Panel: The panel covering the thermostat may be held in place by retainer clips or screws. Use a screwdriver to remove the screws or depress the retainer clips with a small screwdriver.
Step 3: Remove the Plastic Molding (if necessary)
- Inspect the Molding: On some older top freezers, it may be necessary to remove the plastic molding to access the freezer floor.
- Warm the Molding: Warm the plastic molding with a warm, wet towel to make it more pliable and prevent breakage.
- Remove the Molding: Carefully remove the molding without forcing it.
Step 4: Disconnect the Old Thermostat
- Identify the Wires: The thermostat is connected by two wires with slip-on connectors or a wiring harness.
- Remove the Connectors: Firmly pull the connectors or harness off the terminals using needle-nose pliers if necessary. Do not pull on the wires themselves.
- Inspect for Corrosion: Check the connectors and terminals for corrosion. Replace the connectors if they are corroded.
Step 5: Remove the Old Thermostat
- Remove Fasteners: Depending on the design, the thermostat may be clipped or screwed into place. Remove any fasteners to free the old thermostat.
- Handle with Care: Carefully remove the old thermostat from its mounting.
Step 6: Install the New Thermostat
- Position the New Thermostat: Place the new defrost thermostat in the same position as the old one.
- Secure the Thermostat: Attach the thermostat using clips or screws as required.
- Reconnect the Wires: Connect the wires to the new thermostat terminals, ensuring they are securely attached.
Step 7: Reassemble the Freezer
- Replace the Plastic Molding (if removed): Carefully reinstall the plastic molding.
- Reattach the Rear Panel: Secure the rear panel with screws or clips.
- Replace Freezer Components: Reinstall the freezer shelves, icemaker, and any other components you removed.
Step 8: Restore Power and Test
- Plug in the Refrigerator: Restore power by plugging the refrigerator back in.
- Test the Refrigerator: Observe the refrigerator to ensure it is cooling properly and that the defrost cycle is functioning as expected.
Tips and Warnings
- Use Proper Tools: Ensure you use the correct tools to avoid damaging components.
- Handle with Care: When handling plastic components, warm them first to make them more pliable and avoid breakage.
- Consult the Manual: Always refer to your refrigerator’s user manual for specific instructions related to your model.
- Seek Professional Help: If you are unsure about any step or if the problem persists, consider seeking help from a professional technician.
By following these steps, you can effectively replace the defrost thermostat in your refrigerator, ensuring it operates correctly and efficiently. Regular maintenance and timely repairs will help extend the lifespan of your appliance.
