Ruud Furnace Error Codes - Complete Guide

Ruud and Rheem are sister brands using identical control boards. Modern Ruud furnaces use the same 7-segment digital display showing numeric error codes (10, 11, 22, 33, 55, etc.) as Rheem. Also covers Rheem.

All Ruud 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 26

Reversed Polarity

Line voltage polarity reversed - wiring fault.

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 58

Condensate Drain Problem

Condensate drain problem - water buildup in high-efficiency furnace.

Code 59

Condensate Overflow Switch Open

Condensate overflow switch tripped - drain blocked or pan full.

Code 61

Blower Motor Malfunction

Blower motor not operating correctly.

Code 93

Control Board Failure

Internal control board failure.

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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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Ruud Furnace Error Codes - Complete Guide

All Ruud Error Codes

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