Dryer displays E09 and may not heat or may shut down unexpectedly; more common on heat pump models.

Safety first: Heat pump systems contain refrigerant under pressure. Do not attempt to open sealed refrigeration components. Always disconnect power before inspection.

• Clean heat pump coils: Access the front or side panel to view the evaporator and condenser coils of the heat pump. Gently vacuum dust and lint from the fins without bending them.
• Check fan operation: Ensure the circulation fan near the heat pump runs freely and is not obstructed. Replace the heat pump fan motor if seized.
• Listen for compressor: During operation, listen for the compressor starting. If it repeatedly tries to start and clicks off, the compressor or its start relay may be faulty.
• Sensor checks: Inspect wiring to any heat pump NTC sensors or pressure switches. Replace defective heat pump NTC sensors if resistance is out of range.
• Professional service: If E09 persists after cleaning and basic checks, the compressor or sealed system may be defective. This requires specialized tools and must be handled by an authorized De Dietrich service technician.