Freezer displays E4 and may run continuously without proper defrosting, causing heavy frost on the evaporator and poor airflow.

Warning: Disconnect mains power before opening any panels. Avoid bending or puncturing refrigerant lines.

• Manually defrost: Open the door, remove food, and allow the freezer to defrost fully (this can take several hours). Place towels to collect water. Do not use sharp tools to chip ice.
• Access defrost sensor: Remove the inner rear panel to expose the evaporator and defrost sensor (often the same as the evaporator NTC). Confirm it is firmly clipped to the coil or in its designated pocket.
• Check sensor wiring and seating: Ensure the sensor cable is not pulled tight or damaged. Reseat the connector at both the sensor and PCB ends.
• Test sensor: Measure resistance at known temperatures (e.g., in ice water ~0°C). Compare to expected NTC values from service documentation if available. Replace if readings are inconsistent or intermittent.
• Control board inspection: If sensor and wiring are good, inspect the main PCB for burnt components or corrosion around the sensor input. Replacement of the PCB is recommended to be done by a qualified technician.