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U5

U5 - Malfunction of transmission between indoor unit and remote controller (Indoor Unit)

Daikin · Simple Self Diagnosis by Malfunction Code | Daikin

What does U5 mean?

Communication between the indoor unit and its remote controller has failed.

Common Causes

  • Faulty remote controller
  • Wiring issue between unit and controller
  • Interference

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Turn off the power to the indoor unit.

  2. 2

    Check the connection between the indoor unit and the remote controller.

  3. 3

    If using a wireless remote, check batteries and ensure it's within range.

  4. 4

    Restore power and test.

  5. 5

    If the error continues, consult a technician.

Browse all codes in this manual (60)
Verified technical data. Last updated: April 2026

Related Faults

6-06-0 - External protection device activated (Heat reclaim ventilator)6-16-1 - Malfunction of PCB (Heat reclaim ventilator)6-26-2 - Ozone density abnormal (Heat reclaim ventilator)
Source: Simple Self Diagnosis by Malfunction Code | Daikin
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