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H3

H3 - Actuation of high pressure switch (HPS) (Outdoor Unit)

Daikin · Simple Self Diagnosis by Malfunction Code | Daikin

What does H3 mean?

The high-pressure switch in the outdoor unit has activated due to excessively high refrigerant pressure.

Common Causes

  • Blocked airflow
  • Refrigerant overcharge
  • Dirty condenser coils
  • Faulty HPS

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Turn off the unit.

  2. 2

    Ensure air filters and outdoor coil are clean and unobstructed.

  3. 3

    Restore power.

  4. 4

    If the error repeats, call a technician to check refrigerant levels and the HPS.

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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