A. O. Smith Water Heater 0 Flashes: Meaning and Fix

A gas tank water heater reports its fault as a count of LED flashes on the gas control valve, seen through the small window or viewport near the base of the tank. Count the flashes, note the pause (usually three seconds) and watch a second full round before you decide which code it is. Some controls use two groups, such as six flashes then one.

A. O. Smith makes tank water heaters whose gas control valve has a status light that flashes a fault code, then pauses three seconds and repeats. The meaning depends on the control, so match the chart to your model series. Check the model label on your unit before using any chart.

If you smell gas, leave the building and call your gas utility from outside; do not touch switches or the unit. Switch the water heater off and let it cool before you touch any internal part, and call a licensed plumber or water heater technician if you are not sure.

The code meaning comes from the manufacturer document listed under Sources. The causes and steps below are general troubleshooting guidance, not the manufacturer's service procedure.

1. Turn the gas control knob to OFF. If you smell gas, leave the building and call your gas utility from outside; do not touch switches.
2. Follow the lighting instructions on the front of the water heater and confirm through the viewport that the pilot is lit.
3. A pilot that lights but will not hold can mean a tripped thermal switch; A. O. Smith says to check for flammable vapors and for clean combustion air and filter before relighting.
4. Note that the light stays dark for up to 90 seconds of continuous pilot operation while the thermopile warms up.
5. If the pilot will not light at all, check that the piezo igniter sparks and the gas supply pressure is correct.
6. If the code returns after these checks, call a licensed plumber or water heater technician and give them the flash count and the model number from the rating plate.

What does A. O. Smith water heater 0 Flashes mean?

0 Flashes on a A. O. Smith residential standard gas water heater (FVIR, status light on the gas control valve/thermostat) means the control is off or the pilot is out, so the status light is not lit. This is the 'water heater light not blinking' case. A. O. Smith repeats the flash, pauses three seconds, then repeats.

Can I reset the water heater myself?

Turning the gas control knob to OFF, waiting, and relighting it clears some codes. If the same flash count comes back, the fault is still there and the unit will lock out again. Do not bypass a safety device to keep it running.

When should I call a technician?

Call a licensed plumber or water heater technician for anything involving gas, venting, the pilot, the gas control or flammable vapor sensor, or when the code keeps returning after the simple checks.

Part numbers are OEM references; confirm fit by your model number before ordering. Meanings compiled from manufacturer and parts-retailer documentation; see sources below. Unplug the appliance before opening it.

• https://assets.aosmith.com/damroot/Original/10004/327726.pdf