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56

56 — Fan motor -AD Offset abnormal detection fault

Rheem · Air Handlers

What does 56 mean?

This fault indicates an abnormal detection in the fan motor's AD Offset. The issue is likely with the control board's circuit.

Common Causes

  • Control board circuit failure

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Turn off your air handler at the thermostat and its main electrical breaker for 5 minutes, then turn both back on.

  2. 2

    Check the electrical breaker for your air handler. If it's tripped, flip it completely off, then firmly back to the 'On' position.

  3. 3

    Inspect and replace your air filter if it's dirty or clogged. A clean filter ensures proper airflow.

  4. 4

    Look for any flashing lights or error codes on your air handler or thermostat display and check your manual for their meaning.

  5. 5

    If the fault persists, it's best to contact a professional HVAC technician, as the issue may involve internal control board circuits.

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 187)Search more codes in this manual