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31

31 - Faulty inlet thermistor

Rheem · Water Heaters

What does 31 mean?

The thermistor responsible for measuring the incoming water temperature is not functioning correctly. This can lead to inaccurate temperature readings and improper heating.

Common Causes

  • Defective inlet thermistor
  • Wiring issue to the thermistor

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Contact a dealer or qualified service technician to diagnose and replace the faulty thermistor.

  2. 2

    Ensure no wires are loose or damaged leading to the thermistor.

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

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Source: Rheem Water Heaters
Open Manual (Page 77)Search more codes in this manual