A. O. Smith Solid red
A. O. Smith solid red light: pilot recently went out
Short answer
A solid (steady, not blinking) status light on an A. O. Smith gas valve means the pilot was recently put out and the thermopile is cooling down. A. O. Smith calls this "status light on (solid)". Turn the knob to OFF, wait 10 minutes for the thermopile to cool, and then relight the pilot following the label instructions.
In this guide
A. O. Smith's manuals call this state "status light on (solid)", and its support pages call it a continuous light. Whatever color your unit shows, a light that stays on without blinking is a transition state. The pilot was just extinguished, whether you turned it off or it went out on its own, and the thermopile that powers the control is still cooling.
The meaning below comes from the status light chart in A. O. Smith's installation and use manual for its residential gas water heaters with a pilot-powered gas control valve. The same control is used on State and other A. O. Smith-made heaters.
What to do
- Turn the gas control knob to OFF.
- Wait 10 minutes for the thermopile to cool. The control has built-in circuitry that requires this wait.
- Relight the pilot following the instructions on the heater's label.
- Give it up to 90 seconds for the light to start blinking once every three seconds, which is normal operation.
If the pilot keeps going out
A steady light that keeps coming back means the pilot is going out repeatedly. Common reasons are drafts, a dirty pilot, a weak thermopile, a clogged combustion air intake or flammable vapor protection shutting the heater down. Relighting it again and again does not fix those.
- Keep the area around the base of the heater clear of lint and dust.
- Never store gasoline, paint thinner or other flammables near the heater.
- Call a technician if the pilot goes out more than once.
If you smell gas, do not reset the unit or touch any switches. Leave the building and call your gas utility from outside.
Before you call
Note the exact flash pattern, count it twice, and have the model and serial number from the rating label ready. Tell the technician when the light started flashing, whether the pilot is lit, and whether anything was stored or spilled near the heater recently. The serial number also tells you the heater's age, which matters when deciding between a repair and a replacement.
See every code on our A. O. Smith status light codes page.
Common questions
Is a solid red light on an A. O. Smith water heater bad?
Not by itself. It means the pilot just went out and the control is cooling. It becomes a concern if the pilot keeps going out.
Can I relight right away when the light is solid red?
No. A. O. Smith says to wait 10 minutes for the thermopile to cool before relighting.
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Other A. O. Smith codes
| Code | Meaning |
|---|---|
| 0 flashes | Light off: pilot out or thermopile not yet warm |
| Solid red | Solid red light: pilot recently went out, thermopile cooling |
| 2 flashes | Pilot lit but thermopile output too low |
| 4 flashes | Water temperature too high (high limit tripped) |
| 5 flashes | Temperature sensor (thermistor) failure |
| 7 flashes | Gas control valve failure |
| 8 flashes | Thermopile still producing power with the knob off (pilot valve may be stuck open) |