Heat pump dryer does not heat properly, F20 displayed, cycle times extended and clothes remain damp.

Safety first: Unplug the dryer. Heat pump components can be sharp and contain refrigerant under pressure; do not open sealed system yourself.

• Clean condenser: On Hotpoint-Ariston heat pump dryers, remove the lower front panel and slide out the condenser/heat exchanger (if user-removable). Rinse thoroughly to remove lint and dust, allow to dry, and reinstall.
• Check fans: Listen for operation of internal fans during a cycle. If a fan does not run, access and test the fan motor for free rotation and continuity. Replace if faulty.
• Airflow inspection: Ensure all intake and exhaust grilles are clear. Clean lint filter and internal ducts.
• Technician tasks: If F20 persists, a technician must check compressor operation, system pressures, and refrigerant charge. Sealed system repairs require specialized tools and must not be attempted by unqualified persons.