ErrorCodeDoctor
Daikin · Air Conditioner

Daikin Air Conditioner U5 error code

Difficulty: Medium · Cost: $0–$250 · Duration: 5–10m

The U5 error means your Daikin air conditioner detected a communication failure between the indoor unit and the remote controller. This can be caused by a wiring error, two main remote controllers being connected simultaneously, or a faulty PCB. Check the remote controller wiring. If two remote controllers are connected and both are set as main controllers set one as a sub remote controller.

Common causes

  • Transmission error between the indoor unit and remote controller
  • Two remote controllers are both set as main controllers — only one can be main
  • Indoor unit PCB has a fault
  • Remote controller PCB has a fault
  • Electrical noise interference

How to fix it

  1. 1

    Check the remote controller wiring connection to the indoor unit

  2. 2

    If two remote controllers are connected make sure only one is set as the main controller and the other is set as a sub remote controller

  3. 3

    If wiring is correct and settings are right contact a qualified technician to inspect the PCBs

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

U5 error — frequently asked questions

What does the U5 error mean on a Daikin air conditioner?

A communication fault was detected between the indoor unit and the remote controller

What causes the U5 error?

The U5 error is usually caused by: Transmission error between the indoor unit and remote controller; Two remote controllers are both set as main controllers — only one can be main; Indoor unit PCB has a fault; Remote controller PCB has a fault; Electrical noise interference.

Can I fix the U5 error myself?

It's possible for a moderately handy person, but budget 5–10m and expect some disassembly.

How much does it cost to fix the U5 error?

Fixing the U5 error on a Daikin air conditioner typically costs $0–$250, depending on parts and whether you do it yourself or hire a technician.

Is it safe to keep using my air conditioner with the U5 error?

In most cases yes, but it's best to address the U5 error soon — see the fix steps below to resolve it.