Daikin air conditioner error codes
Displayed on the indoor unit or remote when a fault is detected. Always isolate power before inspecting a unit — repairs belong to a qualified technician.
| Code | Meaning | Applies to | |
|---|---|---|---|
| A1 | Indoor PCB defect or internal failure. | All models | Details |
| A5 | Freeze-up protection activated for the indoor heat exchanger. | All models | Details |
| A6 | Indoor fan motor fault. | All models | Details |
| C4 | Faulty indoor heat exchanger temperature sensor. | All models | Details |
| C9 | Faulty indoor suction air (room) temperature sensor. | All models | Details |
| E1 | Outdoor circuit board fault. | All models | Details |
| E7 | Outdoor DC fan motor fault. | All models | Details |
| F6 | High pressure control activated in cooling mode. | All models | Details |
| U0 | Refrigerant shortage or undercharge detected. | All models | Details |
| U2 | Power supply voltage drop or main circuit overvoltage. | All models | Details |
| U4 | Transmission failure between indoor and outdoor units. | All models | Details |
| UA | Indoor-outdoor unit combination fault. | All models | Details |