Indoor unit shows H1 and no warm air is produced at the beginning of heating mode.

Note: On many Royal Clima heat pump models, H1 is an informational code indicating defrost or preheating, not a fault.

• Step 1 – Wait for defrost to complete: Allow 5–15 minutes for the outdoor unit to complete defrost. During this time, indoor fan may stop or blow very low air.
• Step 2 – Check outdoor unit: Ensure the outdoor coil is not completely blocked by ice or snow. Clear snow around the unit to improve airflow.
• Step 3 – Verify filters and airflow: Clean indoor filters and ensure vents are not blocked to reduce defrost frequency.

When to call a technician: If H1 remains permanently or heating never resumes, there may be a sensor or defrost control issue requiring professional diagnosis.