ErrorCodeDoctor
Daikin · Air Conditioner

Daikin Air Conditioner U2 error code

Difficulty: Easy · Cost: $0–$200 · Duration: 5m

The U2 error means your Daikin air conditioner detected an abnormality in the power supply voltage or an instantaneous power failure. This can be caused by a brownout, power surge, or wiring fault. Check the power supply and circuit breaker. If the power supply is stable and the error persists contact a qualified technician.

Common causes

  • Power supply voltage is abnormal — too high or too low
  • An instantaneous power failure or brownout occurred
  • Main circuit wiring has a defect

How to fix it

  1. 1

    Check the circuit breaker for the air conditioner and reset if tripped

  2. 2

    If a power outage or brownout occurred wait for power to stabilise and try restarting

  3. 3

    If the power supply is stable and U2 persists contact a qualified technician to inspect the main circuit wiring

Related Daikin Air Conditioner error codes

1

A0

An external protection device connected to the indoor unit has been activated

hard
2

A1

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

hard
3

A3

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

medium
4

A5

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

easy

U2 error — frequently asked questions

What does the U2 error mean on a Daikin air conditioner?

A power supply abnormality or instantaneous power failure was detected

What causes the U2 error?

The U2 error is usually caused by: Power supply voltage is abnormal — too high or too low; An instantaneous power failure or brownout occurred; Main circuit wiring has a defect.

Can I fix the U2 error myself?

Yes — this is rated an easy fix that most people can do themselves, typically in 5m.

How much does it cost to fix the U2 error?

Fixing the U2 error on a Daikin air conditioner typically costs $0–$200, depending on parts and whether you do it yourself or hire a technician.

Is it safe to keep using my air conditioner with the U2 error?

In most cases yes, but it's best to address the U2 error soon — see the fix steps below to resolve it.