Daikin error code UA
What it means
Indoor-outdoor unit combination fault.
Possible causes
Indoor unit type not compatible with outdoor unit Incorrect piping or wiring configuration Wrong field setting code applied
Suggested fix
Verify installed model combination against Daikin pairing charts and ensure piping and wiring match the approved design; correct field settings and replace any incompatible units rather than bypassing the protection.
Safety first. Isolate the power supply before inspecting any unit. Refrigerant-circuit
and electrical repairs must be carried out by a qualified, registered technician.
Other Daikin codes
- A1 — Indoor PCB defect or internal failure.
- A5 — Freeze-up protection activated for the indoor heat exchanger.
- A6 — Indoor fan motor fault.
- C4 — Faulty indoor heat exchanger temperature sensor.
- C9 — Faulty indoor suction air (room) temperature sensor.
- E1 — Outdoor circuit board fault.
- E7 — Outdoor DC fan motor fault.
- F6 — High pressure control activated in cooling mode.
- U0 — Refrigerant shortage or undercharge detected.
- U2 — Power supply voltage drop or main circuit overvoltage.