Dehumidifier displays E4 and shuts down

Safety first: Unplug the unit. Allow hot components to cool before touching.

• Step 1 – Check airflow: Ensure the rear and sides of the dehumidifier have adequate clearance. Clean the air filter and vacuum dust from the intake and exhaust grilles.
• Step 2 – Inspect condenser coil: If accessible, gently vacuum or brush dust from the condenser coil (the warm coil near the compressor). Blocked fins can cause overheating and trigger E4.
• Step 3 – Locate defrost/overheat sensor: This sensor is usually clipped to the condenser or discharge line. Verify it is firmly attached and its wires are intact.
• Step 4 – Test sensor (advanced): Use a multimeter to measure resistance at room temperature and compare to specifications if available. Replace if open/shorted.
• Step 5 – Restart and monitor: After cleaning and sensor inspection, reassemble, plug in, and run the unit. If E4 recurs quickly, further diagnosis of the control board or sealed system is needed.

When to call a technician: Persistent E4 after cleaning and sensor replacement suggests a deeper electrical or sealed-system fault. Professional service is recommended.