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A126

A126 - Circuit A High Head Pressure Alarm

Carrier · Air Conditioning

What does A126 mean?

An alarm indicating high head pressure in Circuit A. The circuit will stop to prevent damage.

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 thoroughly.

  2. 2

    Check if the outdoor fan is spinning freely and without obstruction.

  3. 3

    Contact a technician to verify the refrigerant charge.

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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