Error code

Rheem gas water heater error code A023

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Is A023 on a Rheem gas water heater an emergency?

Treat it as urgent — deal with it today. If you smell gas, do not touch switches or try to relight anything: leave, and call the gas utility or 911 from outside.

Take the photo. We’ll tell you what it is.

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What A023 means

“Upper Tank temp. too hot.”

— Rheem, Rheem Residential Super High Efficiency gas water heater Use & Care manual (AP21831 Rev 2), alarm and alert codes. Codes vary by model: check your gas water heater’s own manual.

Where A023 fits

Next to A023 in Rheem’s table: A022 (Upper Tank Sensor open) and A024 (Upper Tank sensor shorted).

What to try first

  • Do not use hot water until checked (scald risk); call a qualified technician.

Safety: If you smell gas, do not touch switches or try to relight anything: leave, and call the gas utility or 911 from outside.

How urgent is it?

At least TODAY. fixRAgent treats this code as needing attention today. It points at water where it should not be, overheating, a combustion or ignition safety shutdown, food that may be warming, or a wiring problem. This is fixRAgent’s reading, not the manufacturer’s. A photo can raise it — water near wiring, scorch marks, a gas smell — but a code never lowers what the photo shows.

Who to call

Plumber. Have the model and serial numbers from the label ready — a photo of the label works.

Recalls and manuals

Check whether your model is under a safety recall on the U.S. Consumer Product Safety Commission’s site: cpsc.gov/Recalls. Your owner’s manual is on Rheem’s support site; search it with the model number from the label.