Display shows H1 and the unit does not blow warm air in heating mode; outdoor unit may frost up.

Safety first: No immediate danger; H1 often indicates normal defrost. Do not force the unit to run continuously in heavy frost.

• Observe duration: H1 should clear within several minutes once defrost completes. Warm air will resume afterward.
• Check outdoor coil: Inspect the outdoor unit for excessive ice buildup. Clear snow and ensure drainage is not blocked.
• Improve installation conditions: Ensure the outdoor unit has good airflow and is not installed in a location where meltwater refreezes on the coil.
• If H1 stays on and no heating: The defrost sensor or control may be faulty. A technician should test the defrost temperature sensor and outdoor PCB.