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66

66 - Faulty bypass motor

Rheem · Water Heaters

What does 66 mean?

The bypass motor, which is part of the water flow regulation system, is not working correctly. This can impact the unit's ability to heat water efficiently.

Common Causes

  • Bypass motor failure
  • Electrical connection issue
  • Mechanical obstruction

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Contact a dealer or qualified service technician to diagnose and repair or replace the bypass motor.

  2. 2

    Check for any obvious obstructions around the motor.

Browse all codes in this manual (70)
Verified technical data. Last updated: April 2026

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1111 - Gas shut-off valve is not fully open1212 - Gas service interrupted or LP gas low13Hot and cold water lines reversed
Source: Rheem Water Heaters
Open Manual (Page 77)Search more codes in this manual