Can I fix A.O. Smith code 1 flash myself?

Start with these safe checks: If you have no hot water with 1 flash, check the temperature knob setting ("Hot" is about 120°F). No service needed for the light itself.

When should I call a technician for code 1 flash?

No service needed for the light itself. 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 1 flash: Normal operation

A.O. Smith standard gas water heaters

What 1 flash means

One flash (a bright/dim heartbeat) means normal operation. No action needed.

Likely causes

Normal

Safe first checks

If you have no hot water with 1 flash, check the temperature knob setting ("Hot" is about 120°F).

When to stop

No service needed for the light itself.

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.