Dehumidifier shows E4 and stops cooling, fan may run intermittently

Warning: Always unplug the Cecotec dehumidifier before opening the casing. Sharp metal edges around the coil can cause injury.

How to proceed:

• Check ambient conditions: If the room is very cold (near 5–10°C), the unit may enter frequent defrost. Move it to a slightly warmer room and see if E4 clears after a power reset.
• Access defrost sensor: Remove the rear cover to expose the evaporator. The defrost sensor is usually clipped to the lower part of the evaporator or attached to the refrigerant tube.
• Verify attachment: Ensure the sensor is firmly clipped or taped to the coil/tube. Reattach with aluminum tape or the original clip if loose.
• Inspect wiring and connector: Follow the sensor wires to the PCB. Look for damage or loose connectors. Reseat the plug.
• Test sensor: Disconnect the sensor and measure resistance at room temperature and again after briefly cooling it with a cold pack. Resistance should change smoothly. If it is open or shorted, replace the sensor.
• Replace sensor: Install a Cecotec-compatible defrost NTC sensor and secure it in the same location.
• PCB diagnosis: If E4 remains with a new sensor, the defrost control circuit on the main board may be defective and should be replaced by a professional.