ErrorCodeDoctor
Daikin · Air Conditioner

Daikin Air Conditioner A0 error code

Difficulty: Hard · Cost: $80–$250 · Duration: Requires professional service

The A0 error means an external protection device connected to the indoor unit terminal strip (T1-T2) has been activated. This is a safety shutdown triggered by a device wired into the indoor unit — such as a float switch or external sensor. Contact a qualified technician to inspect the protection device and its wiring.

Common causes

  • External protection device wired to the T1-T2 terminals has triggered
  • Protection device wiring is defective or has a fault

How to fix it

  1. 1

    Contact a qualified technician to inspect the external protection device and associated wiring

Related Daikin Air Conditioner error codes

1

A1

A fault was detected in the indoor unit PCB (control board)

hard
2

A3

The drain level control system has detected an abnormality — drain may be clogged

medium
3

A5

Freeze-up protection (cooling) or high pressure control (heating) has activated — check the air filter

easy
4

A6

The indoor unit fan motor has a fault

hard