Dehumidifier shuts down and displays E4 on the panel

Safety: Unplug the unit before inspection. Do not attempt to open the sealed refrigeration system yourself; refrigerant work must be done by a licensed technician.

Steps to address E4:

• Check ambient conditions: Ensure the dehumidifier is used within the specified temperature range (typically 41–95°F / 5–35°C). Operating in a very cold room can cause coil freeze and E4.
• Clean the air filter: Remove the front/rear filter and wash with mild soap and water. Let it dry completely and reinstall. Restricted airflow can cause coil temperature faults.
• Inspect airflow: Make sure there is at least 8–12 inches of clearance around the intake and exhaust grilles. Remove any obstructions or dust buildup on the coil fins.
• Defrost the unit: If you see ice on the evaporator coil, unplug the unit and let it thaw completely (place towels under the unit). After thawing, restart and monitor.
• Sensor check: If E4 appears immediately on startup in normal conditions, the evaporator sensor or main board may be misreading. Follow the E2 sensor inspection steps to verify the coil sensor.
• Refrigerant issues: If the coil repeatedly ices up or the unit barely removes moisture before E4 appears, the sealed system may be undercharged or restricted. This requires a professional HVAC/refrigeration technician; do not attempt to open refrigerant lines yourself.