Display shows H1 and unit does not cool; may run fan only for a period.

H1 on many Klarstein heat pump models indicates automatic defrost, not a fault, unless it persists abnormally long.

Steps:

• Wait cycle: Allow 10–15 minutes for the defrost cycle to complete. The unit should resume normal operation automatically.
• Check outdoor unit: Ensure the outdoor coil is not buried in snow or ice. Clear snow and debris around the unit.
• Airflow: Maintain adequate clearance around the outdoor unit for proper airflow.
• Sensor check (if H1 never clears): Inspect the outdoor coil/defrost sensor and wiring. Replace the sensor if readings are abnormal.