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28

Fault code 28 — Compressor drive Q axis current control error

Rheem · Air Handlers

What does 28 mean?

An error in controlling the Q-axis current for the compressor drive has been detected. This may indicate system overload or a control board issue.

Common Causes

  • System overload, phase current is too high
  • Control board fails

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Verify that the system is not overloaded.

  2. 2

    Confirm that the stop valve is open.

  3. 3

    If the system is operating normally, the main PCB (control board) might be faulty.

Browse all codes in this manual (51)
Verified technical data. Last updated: April 2026

Related Faults

1Fault code 1 — Inverter DC voltage overload fault10Fault code 10 — PFC fault (level)11Fault code 11 — PFC power detection of failure
Source: Rheem Air Handlers
Open Manual (Page 186)Search more codes in this manual