Error code reference

Rheem Water Heater Error Code 12

Gas shut-off valve is not fully opened, gas service has been interrupted, or LP gas is running low (LP models only).

SourceRheem Tankless Water Heater - Use & Care Manual with Installation Instructionsp. 25, 26

Diagnostic procedure

The full 12 procedure

Step 1 is visible so you can confirm you are on the right page. The remaining steps, the ones that tell you whether to actually replace a part, unlock with any pass.

MyPros+ · DiagnosticsStep 1 preview

First diagnostic step

Check shut-off valve and open completely. Contact your gas utility company if service has been interrupted. Refill or replace LP gas container if applicable.

SourceRheem Tankless Water Heater - Use & Care Manual with Installation Instructionsp. 25, 26

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Where this code is documented

1 manual in the MyPros+ library documents this code for Rheem water heater.

Models covered by the manuals that document this code

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The full 12 procedure

Where this code is documented

Models covered by the manuals that document this code

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