Dryer shows E12; on heat pump models, drying performance is poor and cycle times are long.

Safety first: Unplug the dryer before accessing internal components. Refrigerant systems must only be opened by certified technicians.

• Clean heat exchanger: Access the front or side heat exchanger filter and remove it. Clean thoroughly under running water and allow to dry. If the heat exchanger itself is accessible, gently vacuum dust from the fins without bending them.
• Check heat pump fan: Locate the fan that blows air across the heat pump coil. Ensure it spins freely and is not obstructed by lint. Replace the fan motor if it does not run when powered.
• Observe compressor operation: During a test cycle, listen for the compressor starting (a low humming sound) after a few minutes. If it does not start, or starts and quickly stops, there may be an electrical or refrigerant issue requiring professional service.
• Refrigerant issues: If the dryer runs but never produces warm air and E12 appears, the system may be low on refrigerant or have a leak. Do not attempt to open the sealed system yourself; contact a qualified refrigeration technician.