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H4

H4 - Low-pressure switch open circuit

Daikin · Air Conditioning

What does H4 mean?

The low-pressure switch has an open circuit, suggesting a possible pressure issue or switch fault.

Common Causes

  • Low pressure switch open circuit.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Verify that the system has adequate refrigerant charge.

  2. 2

    Inspect the wiring and connection of the low-pressure switch.

  3. 3

    A technician should check system pressures and the switch's integrity.

Browse all codes in this manual (79)
Verified technical data. Last updated: April 2026

Related Faults

A0A0 - External protection activeA1A1 - Indoor PCB failureA2A2 - Malfunction of freezing protection
Source: Daikin Air Conditioning
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