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U2

U2 - Malfunction of power supply or instantaneous power failure (Outdoor Unit)

Daikin · Simple Self Diagnosis by Malfunction Code | Daikin

What does U2 mean?

This error code indicates a problem with the power supply to the outdoor unit or a recent, sudden power interruption.

Common Causes

  • Unstable power source
  • Loose electrical connections
  • Internal power component failure

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Turn off the power to the unit at the breaker.

  2. 2

    Check all electrical connections to the unit.

  3. 3

    Restore power and observe if the error code is resolved.

  4. 4

    If the issue continues, contact a qualified 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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