CodeRegistry
Brands
  1. Home
  2. Carrier
  3. Air Conditioning
  4. A051
About·Privacy·Terms

CodeRegistry — Your global library for technical solutions.

For your safety: always follow the equipment manufacturer’s official manuals. CodeRegistry is an independent help site and is not affiliated with the brands listed here.

A051

A051 - Compressor 1 Stuck On Failure

Carrier · Air Conditioning

What does A051 mean?

This alarm indicates that Compressor 1 in Circuit A is stuck in the 'on' position. The system will turn off all compressors to prevent damage.

Common Causes

  • Welded contact in the compressor control circuit

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Check for any external shutdown commands.

  2. 2

    Inspect the wiring to Compressor 1 for damage or loose connections.

  3. 3

    If the issue persists, contact a qualified HVAC technician to diagnose the compressor control.

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

Related Faults

A052A052 - Compressor 2 Stuck On FailureA055A055 - Compressor 1 Stuck On Failure (Circuit B)A056A056 - Compressor 2 Stuck On Failure (Circuit B)
Source: Carrier Air Conditioning
Open Manual (Page 100)Search more codes in this manual