Refrigerator runs continuously or cycles erratically; display shows E3 indicating defrost sensor or defrost fault.

Safety: Unplug the refrigerator before accessing the evaporator area. Edges of metal panels and evaporator fins can be sharp; wear cut-resistant gloves.

Steps to troubleshoot:

• 1. Check for frost buildup: Remove freezer drawers and inspect the rear panel. If the panel is bowed or covered in thick frost, the defrost system is likely compromised.
• 2. Access the evaporator: Remove screws securing the rear freezer panel and gently pull it forward. Locate the evaporator NTC sensor, usually clipped to the evaporator tubing or embedded in a small plastic housing attached to the coil.
• 3. Inspect sensor placement: Ensure the sensor is firmly clipped to the evaporator and not hanging loose. A loose sensor can misread temperature and trigger E3.
• 4. Test the sensor: Disconnect the sensor and measure resistance at a known temperature (e.g., room temperature after defrosting). Compare to typical NTC values. If resistance is far out of range, replace the sensor.
• 5. Wiring and board: Check the harness from the evaporator area to the main control board for damage from ice, rubbing, or rodents. Repair or replace damaged wiring. If sensor and wiring are good, the main control board may be defective.
• 6. Replace faulty parts: Install a new evaporator/defrost NTC sensor if needed. If the board is at fault, have a professional replace the main control board.

After repair: Fully defrost the evaporator, reassemble panels, restore power, and allow 24 hours for temperatures to stabilize.