H1 displayed during heating; outdoor unit stops and indoor fan may slow or stop

Note: H1 on many Camry heat pump models indicates that the unit is in defrost mode, not necessarily a fault.

• 1. Observe operation: During H1, the outdoor fan stops and the system reverses to melt ice on the outdoor coil. This can last several minutes.
• 2. Check outdoor coil: Confirm that frost or ice is present and that it melts away by the end of the defrost cycle.
• 3. Frequency of H1: If H1 appears very frequently (every few minutes) or lasts excessively long, inspect the outdoor coil sensor and coil cleanliness.
• 4. Clean coil and ensure drainage: Remove debris and ensure meltwater can drain away from the base of the outdoor unit.
• 5. Sensor/PCB diagnosis: If defrost cycles are abnormal, a technician should test the defrost sensor and outdoor PCB logic.