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5

Fault code 5 — Loss phase detection fault (speed pulsation)

Rheem · Air Handlers

What does 5 mean?

The unit has detected a loss of phase in the compressor, leading to speed pulsations. This could be a compressor issue or a control board fault.

Common Causes

  • Compressor phase lost
  • Bad control board components
  • Compressor insulation fault

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Check the compressor wire connections.

  2. 2

    Replace the main PCB if connections are secure.

  3. 3

    If the issue continues, the compressor might need replacement.

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