Rheem Furnace Error Codes - Complete Guide

Modern Rheem and Ruud furnaces use a 7-segment digital display showing numeric error codes (10, 11, 22, 33, etc.). Older models use LED flash codes. This guide covers the numeric format used in current installs. Also covers Ruud.

All Rheem Error Codes

Code 10

One-Hour Lockout

One-hour soft lockout after repeated ignition failures.

Code 11

Ignition Failure

Burners failed to ignite after multiple attempts.

Code 12

Weak Flame Signal

Weak or low flame signal detected by flame sensor.

Code 13

Flame Lost

Flame established but lost mid-cycle.

Code 14

Unexpected Flame

Flame detected when gas valve should be off - leaky valve.

Code 22

High Limit Switch Fault

High limit switch open - overheating. Usually restricted airflow.

Code 33

Rollout Switch Open (SAFETY)

Rollout switch tripped - possible cracked heat exchanger and CO risk.

Code 55

Pressure Switch Issue

Pressure switch fault - vent, inducer, or switch issue.

Code 57

Pressure Switch Calibration

Pressure switch calibration fault.

Code 61

Blower Motor Malfunction

Blower motor not operating correctly.

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If you don't see your code here, try our master error code lookup covering all major brands, or our symptom-based diagnostic tool.

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Rheem Furnace Error Codes - Complete Guide

All Rheem Error Codes

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