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P126

P126 - Circuit A High Head Pressure, Comp Shutdown

Carrier · Air Conditioning

What does P126 mean?

The head pressure in Circuit A is too high, causing the compressor to shut down or stage down. This is a protective measure.

Common Causes

  • Dirty condenser coil
  • Condenser fan failure
  • System overcharged with refrigerant

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Clean the outdoor unit's condenser coils.

  2. 2

    Ensure the outdoor fan is running properly.

  3. 3

    A technician should check the refrigerant charge level.

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

Related Faults

A051A051 - Compressor 1 Stuck On FailureA052A052 - Compressor 2 Stuck On FailureA055A055 - Compressor 1 Stuck On Failure (Circuit B)
Source: Carrier Air Conditioning
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