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A128

A128 - Digital Scroll High Discharge Temperature Alarm

Carrier · Air Conditioning

What does A128 mean?

This alarm indicates high discharge temperature for the digital scroll compressor. Compressor A1 is locked off.

Common Causes

  • Refrigeration problem
  • Overheating
  • Airflow restrictions

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Verify that air filters are clean and replaced if necessary.

  2. 2

    Ensure the unit's ventilation paths are clear.

  3. 3

    Contact an HVAC professional to investigate refrigeration system issues.

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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