CodeRegistry
Brands
  1. Home
  2. Rheem
  3. Water Heaters
  4. A012
About·Privacy·Terms

CodeRegistry — Your global library for technical solutions.

For your safety: always follow the equipment manufacturer’s official manuals. CodeRegistry is an independent help site and is not affiliated with the brands listed here.

A012

A12 - Flame Detected During Standby/Disabled Mode

Rheem · Water Heaters

What does A012 mean?

Flame was detected when the unit should be in a standby or disabled mode. This could indicate an issue with the flame sensor or gas valve.

Common Causes

  • Flame sensor malfunction
  • Gas valve issue

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Turn the unit off and then on again to clear the error code.

  2. 2

    If the problem persists, contact technical support or a service provider.

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

Related Faults

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 42)Search more codes in this manual