Freezer not Defrosting / Ice Buildup: Common Causes & How to Fix

Repair Instructions:

The defrost thermostat monitors the temperature of the evaporator coils. When the coils become too cold, the thermostat closes to allow electricity to flow to the defrost heater. This occurs during the defrost cycle when the heater melts frost accumulating on the coils. If the thermostat is faulty, the contacts won't close to power the heater. To check if the thermostat is defective, use a multimeter to test for continuity. If there is no continuity when the thermostat reaches its low operating temperature, replace it.

How to Replace Freezer Defrost Thermostat

1. Unplug the freezer - Unplug the freezer from the electrical outlet to avoid electric shock.

2. Remove food and shelves - Take out all food items and removable shelves from the freezer to provide easy access.

3. Locate thermostat - The defrost thermostat is usually located behind the back freezer wall. Consult the freezer's user manual if you can't find it.

4. Disconnect thermostat wires - Remove the thermostat cover and disconnect the wiring harness by pulling it off the thermostat terminals.

5. Unscrew thermostat - Unscrew and remove the old thermostat from the freezer wall.

6. Install new thermostat - Screw in the new thermostat and snap the wiring harness onto the terminals. Ensure the connections are tight.

7. Replace cover and shelves - Put the thermostat cover back on and return the shelves and food items to the freezer.

8. Plug in freezer - Plug the freezer back into the electrical outlet and check that it starts up normally.

9. Test operation - Allow the freezer to cool down completely, then confirm the new thermostat cycles on and off as expected during defrost cycles.

Repair Instructions:

The defrost control board regulates when the defrost cycle runs. If the board malfunctions, the freezer will not initiate the defrost cycle. Prior to replacing the defrost control board, first examine the defrost heater and defrost thermostat. If the heater and thermostat are functioning correctly, the defrost control board is likely faulty. Replacing a defective defrost control board allows the freezer to go through the regular defrost cycle again to prevent frost build up on the evaporator coils.

How to Replace Freezer Defrost Control Board

1. Unplug freezer - Unplug the power cord before starting to avoid electric shock.

2. Locate control board - The defrost control board is mounted to the back freezer wall.

3. Disconnect wiring - Detach all wiring harness connectors from the old control board terminals.

4. Remove mounting screws - Unscrew and remove any screws securing the control board.

5. Install new board - Position the replacement control board and secure with mounting screws.

6. Reconnect wiring - Attach all wiring harness connectors to the corresponding terminals on the new board.

7. Confirm connections - Double check that all wires are securely reconnected.

8. Neatly tuck wires - Make sure all wiring is neatly tucked away and not obstructing any components.

9. Plug in freezer - Restore power once the new control board is fully installed.

10. Test operation - Allow the freezer to cycle on and off to ensure proper functioning.

Repair Instructions:

The main control board controls electricity to all freezer parts, including the defrost system. If the main board malfunctions, it may stop powering the defrost system. Control boards are often misdiagnosed. Prior to replacing the main board, first test all defrost system components. If none of the defrost parts are faulty, consider replacing the main control board. Testing the defrost heater, thermostat, timer, and other components first prevents unneeded replacement of the main board. Only replace the main control board if other defrost system parts are confirmed to be working properly.

How to Replace Freezer Control Board:

1. Safety Precautions:

   • Make sure your safety by unplugging the freezer or disconnecting it from the power source to prevent electrical accidents.

2. Prepare the Workspace:

   • Empty the freezer and remove any items from inside to access the control board easily.

3. Locate the Control Board:

   • The control board is typically located on the rear interior wall of the freezer or inside the control panel on the exterior of the appliance.

4. Disconnect Wiring:

   • Carefully take note of how the wires are connected to the control board. Unplug or disconnect the wires from the board, remembering their positions.

5. Remove the Old Control Board:

   • The control board may be secured with screws or clips. Remove these fasteners to release the old board from its mounting location.

6. Replace with a New Control Board:

   • Position the new control board in the same location as the old one, ensuring it's properly aligned with any mounting holes or brackets.

7. Reconnect Wiring:

   • Reattach the wires to the new control board, making sure they are connected in the same way as on the old board.

8. Secure the New Board:

   • Fasten the new control board in place with screws or clips.

9. Restore Power:

   • Plug the freezer back in or reconnect it to the power source.

10. Test the Freezer:

    • Make sure the freezer is running and cooling as expected. Adjust the temperature settings on the control board to the desired level.

11. Final Checks:

    • Monitor the freezer for a while to verify that it maintains the set temperature and functions properly.

Repair Instructions:

If the door gasket does not seal properly, ice can accumulate where air leaks through. Inspect the gasket for any kinks or twists. Try smoothing kinks using a hair dryer's heat. If the gasket is damaged or worn out, replacement is required. Check for cracks, brittleness, or detachment from the door frame. Test the seal by closing a piece of paper in the door and tugging - it should not pull out easily. Apply a thin layer of petroleum jelly to the gasket every few months to maintain flexibility. Replacing a worn or damaged gasket improves the seal and prevents cold air loss and frost buildup from air leaks.

How to Replace Freezer Door Gasket

1. Unplug freezer - Unplug the freezer to avoid electric shock while working on it.

2. Remove old gasket - Use a flathead screwdriver to pry up the old gasket from the door frame. Remove any remaining adhesive residue.

3. Clean surface - Wipe down the freezer door frame thoroughly to remove dirt and debris. Ensure the surface is dry.

4. Apply adhesive - Run a bead of gasket adhesive along the door frame where the new gasket will be installed.

5. Install new gasket - Starting at the corner, press the new gasket firmly into place along the adhesive on the frame.

6. Trim excess - Use scissors to trim off any excess gasket material around the door.

7. Allow adhesive to dry - Let the adhesive cure fully before using the freezer, usually 24-48 hours.

8. Plug in freezer - Plug the freezer back in and make sure the door seals properly when closed.

9. Test seal - Place a piece of paper between the gasket and frame and close the door. The paper should be held firmly in place and difficult to pull out, indicating a good seal.

Repair Instructions:

In self-defrosting freezers, the defrost heater system activates periodically to melt frost building up on the evaporator coils. If the defrost heater is faulty, the defrost mechanism will fail, allowing frost to continue accumulating on the coils. To check if the defrost heater is defective, use a multimeter to test for continuity. If there is no continuity, the defrost heater needs replacement. Replacing a defective defrost heater enables the self-defrosting system to properly melt away frost so it does not reduce the freezer's efficiency.

How to Replace Freezer Defrost Heater Assembly:

1. Safety Precautions:

   • Prioritize safety by unplugging the freezer from the power source to prevent electrical accidents.

2. Prepare the Workspace:

   • Empty the freezer and remove any items from inside to access the defrost heater assembly easily.

3. Locate the Defrost Heater Assembly:

   • The defrost heater assembly is typically located behind the rear panel of the freezer.

4. Remove the Rear Panel:

   • To access the defrost heater assembly, you'll need to remove the rear panel. This panel is often held in place with screws. Remove these screws and carefully take off the panel.

5. Identify the Defrost Heater Assembly:

   • Locate the defrost heater assembly, which is a coiled wire element typically secured to the evaporator coils.

6. Disconnect Wiring:

   • Carefully note how the wires are connected to the defrost heater assembly. Unplug or disconnect the wires, remembering their positions.

7. Remove the Old Heater Assembly:

   • The defrost heater assembly is often held in place by clips or brackets. Carefully detach it from these securing mechanisms.

8. Replace with a New Defrost Heater Assembly:

   • Position the new defrost heater assembly in the same location as the old one, making sure it's properly aligned and secured.

9. Reconnect Wiring:

   • Reattach the wires to the new defrost heater assembly, ensuring they are connected in the same way as on the old assembly.

10. Replace the Rear Panel:

    • Reattach the rear panel and secure it in place with the screws you removed earlier.

11. Plug the Freezer Back In:

    • Reconnect the freezer to the power source, maing sure it's properly plugged in.

12. Test the Freezer:

    • Power on the freezer and monitor it to ensure the new defrost heater assembly functions correctly and prevents frost buildup.

13. Final Checks:

    • Confirm that the freezer maintains the desired temperature and that the defrost heater assembly performs its function without any issues.

Repair Instructions:

In some models, the user control and display board also regulates the defrost system. These boards are often misdiagnosed. Prior to replacing the user control board, first examine all defrost system parts. If none of the defrost components are faulty, consider replacing the user control and display board. Testing the defrost heater, thermostat, timer, and other components first prevents unneeded replacement of the user control board. Only replace the user control and display board if other defrost system parts are confirmed to be working properly.

How to Replace Freezer User Control and Display Board:

1. Safety Precautions:

   • Prioritize safety by unplugging the freezer from the power source to prevent electrical accidents.

2. Prepare the Workspace:

   • Empty the freezer and remove any items from inside to access the control and display board easily.

3. Locate the User Control and Display Board:

   • The control and display board is typically situated on the freezer door or inside the freezer compartment, depending on the freezer model.

4. Disconnect Wiring:

   • Carefully take note of how the wires are connected to the control board. Unplug or disconnect the wires from the board, remembering their positions.

5. Remove the Old Control and Display Board:

   • The control and display board is usually secured with screws, clips, or brackets. Remove these fasteners to release the old board from its mounting location.

6. Replace with a New User Control and Display Board:

   • Position the new control and display board in the same location as the old one, making sure it's properly aligned with any mounting holes or brackets.

7. Reconnect Wiring:

   • Reattach the wires to the new control board, making sure they are connected in the same way as on the old board.

8. Secure the New Board:

   • Fasten the new user control and display board in place with screws, clips, or brackets.

9. Plug the Freezer Back In:

   • Reconnect the freezer to the power source, ensuring it's properly plugged in.

10. Test the Freezer:

    • Power on the freezer and check that the control board functions correctly. Verify that the freezer maintains the desired temperature and that the display board responds to user input.

11. Final Checks:

    • Monitor the freezer for a while to verify that the control and display board performs its functions without any issues.

Repair Instructions:

The defrost timer activates the defrost heater periodically to melt frost on the evaporator coils. If faulty, the timer may not start the defrost cycle or power the heater during it. To check if the timer is defective, slowly turn the dial into the defrost cycle. The compressor should stop and the heater should activate. If the timer does not send electricity to the defrost parts or end the defrost cycle within 30 minutes, it is likely defective and requires replacement. This allows the timer to turn on the defrost heater regularly to clear frost accumulation so the freezer can function efficiently.

How to Replace Freezer Defrost Timer:

1. Safety Precautions:

   • Prioritize safety by unplugging the freezer from the power source to prevent electrical accidents.

2. Prepare the Workspace:

   • Empty the freezer and remove any items from inside to access the defrost timer easily.

3. Locate the Defrost Timer:

   • The defrost timer is typically situated on the rear exterior of the freezer, often behind a protective cover or panel.

4. Identify Wiring Connections:

   • Carefully note how the wires are connected to the defrost timer. Take a photo or make a diagram to remember the connections.

5. Release the Old Defrost Timer:

   • The timer is usually secured with screws or clips. Remove these fasteners to release the old timer from its mounting location.

6. Replace with a New Defrost Timer:

   • Position the new defrost timer in the same location as the old one, making sure it's properly aligned with any mounting holes or brackets.

7. Reconnect Wiring:

   • Reattach the wires to the new defrost timer, ensuring they are connected in the same way as on the old timer.

8. Secure the New Timer:

   • Fasten the new defrost timer in place with screws or clips.

9. Plug the Freezer Back In:

   • Reconnect the freezer to the power source, making sure it's properly plugged in.

10. Test the Freezer:

    • Power on the freezer and monitor the defrost cycle. Check that the new timer functions correctly, initiating defrost cycles as intended.

11. Final Checks:

    • Confirm that the freezer maintains the desired temperature and that the defrost timer performs its function without any issues.

Repair Instructions:

Chest freezers and certain upright freezers with evaporator tubing in the shelves require manual defrosting. This means disconnecting power to the freezer for a period to melt built-up frost and ice. If the accumulation reaches 1/4 to 1/2 inch thick, defrosting is needed. To defrost, unplug the freezer and remove any food items. Keep the door open as the ice melts to allow water to drain out. Use towels to soak up excess water. Avoid using sharp tools to scrape ice as they can damage the freezer interior. Once fully defrosted, clean and dry the interior before turning the freezer back on. Performing periodic manual defrosting maintains freezer efficiency.

Repair Instructions:

Excessive frost buildup on food and around the door opening typically indicates the door was left open or ajar for an extended time. Frequent frost accumulation can reduce freezer efficiency and force more frequent defrosting. To prevent excessive frost, make sure the door is completely closed after each use. Check that the door gasket seals properly all the way around. Replace the gasket if it is cracked or damaged. Organize food containers to prevent blocking the door. Listen for the door latch clicking when closed. Take note of any objects obstructing full door closure.