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20

Fault code 20 — Temperature abnormal

Rheem · Air Handlers

What does 20 mean?

An abnormal temperature reading has been detected within the system. This could be due to various factors affecting temperature sensors or the control board.

Common Causes

  • Temperature sensor issue
  • Control board fault
  • Environmental factors

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Ensure the unit is operating within its specified temperature range.

  2. 2

    Check for any obstructions blocking airflow around temperature sensors.

  3. 3

    If the problem persists, the control board or a temperature sensor may need service.

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