What does error code 5 flashes mean on a A.O. Smith water heater?

Sensor failure. The temperature sensor failed.

Can I fix A.O. Smith code 5 flashes myself?

Start with these safe checks: Turn the gas control knob to OFF and the main gas supply OFF. A.O. Smith's repair is replacing the gas control valve/thermostat. Call a qualified technician.

When should I call a technician for code 5 flashes?

A.O. Smith's repair is replacing the gas control valve/thermostat. Call a qualified technician. Smell gas? Leave right away, don't touch light switches or phones inside, and call your gas utility or 911 from outside. Never open a gas valve, burner, gas line, vent or flue connection, or bypass a safety switch. Repeated lockouts, scorching, soot, or a CO alarm mean shut it off and call a licensed gas technician.

A.O. Smith water heater error code

A.O. Smith water heater code 5 flashes: Sensor failure

A.O. Smith standard gas water heaters

What 5 flashes means

The temperature sensor failed.

Likely causes

Sensor failure

Safe first checks

Turn the gas control knob to OFF and the main gas supply OFF.

When to stop

A.O. Smith's repair is replacing the gas control valve/thermostat. Call a qualified technician.

Checked against: A.O. Smith Residential Standard Gas Water Heater Service Handbook: diagnostic flash codes. Codes can differ by model and year, so confirm with your owner's manual.