Dehumidifier displays E4 and shuts down, often after running for a short time

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

• Check ambient conditions: Ensure the dehumidifier is used within the specified temperature range (typically 5–35°C). Operating in very cold rooms can cause icing and trigger protection.
• Clean air filter and grilles: Remove and wash the air filter with mild soap and water. Let it dry completely before reinstalling. Vacuum dust from intake and exhaust grilles.
• Inspect coils: Remove the front panel and inspect the evaporator and condenser coils. If they are clogged with dust, clean gently with a soft brush and vacuum. Do not bend the fins.
• Defrost the unit: If you see heavy ice on the evaporator, leave the unit unplugged with panels open until all ice melts. Then restart and monitor.
• Check fan operation: Power the unit and listen for the fan. Weak or non‑running fans reduce airflow and cause high pressure. If the fan is not running properly, see fan-related entries.
• Call a technician for refrigerant issues: If E4 persists after cleaning and ensuring proper conditions, there may be a refrigerant leak or a faulty pressure switch. These require professional tools and must not be DIY.