How to Fix / Troubleshooting

Safety first: Unplug the unit before cleaning or accessing internal parts.

Steps:

1. Check for ice: Remove the front cover and inspect the evaporator coil for ice buildup when the unit is blowing warm air. If iced, turn off cooling and run fan-only until ice melts.
2. Clean filters and coils: Ensure maximum airflow by cleaning filters and both coils.
3. Fan operation: Verify that both indoor and outdoor fans run continuously when cooling is demanded. Intermittent fans can cause temperature swings.
4. Sensor check: Inspect and reseat the room and evaporator sensors; replace if readings are erratic.
5. Professional diagnosis: If the problem persists, a technician should check refrigerant charge and control board operation.

Unit runs in Cool mode but occasionally blows warm air, then cools again.

Possible Causes