A. O. Smith or State Water Heater Igniter Not Working

The Short Answer: A. O. Smith and State gas tanks use two kinds of igniter. Standing-pilot models have a push-button piezo igniter that sparks to light the pilot. Power-vent models have no pilot; a hot-surface igniter glows and lights the burner after the blower proves. Check gas, power and the status light, follow the label once, then call a technician.

A. O. Smith and State are one family

State Industries has been part of A. O. Smith since 2001 (A. O. Smith history (opens in a new tab)), and State Select tanks use the same kinds of controls and igniters described here. What matters is the venting and control type on your model, so start with the rating plate and the lighting label.

Which igniter does your heater have?

State’s 2014 sheet for Select direct-vent models lists a push-button piezo ignitor with a thermopile-powered electronic gas valve (SRGSS04812 (opens in a new tab)). Its 2012 sheet for Select power-vent models lists a silicon nitride hot-surface ignitor that “eliminates standing pilot” (SRGSS00905 (opens in a new tab)). A. O. Smith’s power-vented gas manual describes the same hot-surface sequence and warns on its label: “This appliance does not have a pilot… Do NOT try to light the burner by hand” (A. O. Smith 100366722 (opens in a new tab)). Other A. O. Smith product lines, including condensing models, use their own controls, so check your manual before applying any of this.

Standing pilot: the piezo will not light the pilot

When you press the piezo button, you should hear a click and, through the viewport, see a small spark near the pilot. If the spark is there but the pilot does not light, the igniter is doing its job; the problem is gas reaching the pilot. If there is no spark, the piezo, its wire, or the electrode may be at fault. A. O. Smith’s service chart for these valves follows the same split: no spark points to the igniter and its wiring; a spark with no pilot points to gas supply (electronic valve chart (opens in a new tab)).

If the pilot lights but goes out when you release the knob, the igniter is not the problem; see why a gas water heater pilot will not stay lit. For more on the button itself, see piezo igniter will not spark.

Power vent: no glow, or glow but no flame

On the power-vented models in A. O. Smith’s manual, the order matters. The blower must run and the pressure switch must close before the igniter is energized. The control then tries to light the burner up to three times; if it does not sense flame, it locks out and flashes a code on the status light.

So a dark igniter is not always a failed igniter. The manual’s troubleshooting table lists these causes for the specific symptom “hot surface igniter not glowing following warm-up period”: reversed polarity at the 120-volt outlet, a defective igniter, or a defective gas control. Other lockouts happen earlier in the sequence. If the blower does not start or runs without lighting, the cause is usually power, venting or the pressure switch; see power vent water heater problems.

Status-light codes for the Honeywell/Resideo control in that manual include:

These meanings are from that one manual. Read the code chart printed on your control or in your own manual; other A. O. Smith and State controls use different charts. A failed trial for ignition can come from the igniter, the gas supply, the flame sensor or the control, so a six-one code does not by itself prove the igniter is bad.

What you can check safely

• Gas smell. If you smell gas, stop and leave. The A. O. Smith label also says to smell next to the floor before operating, because some gas is heavier than air.
• Gas supply. The shutoff handle in the gas line to the heater is open when parallel to the pipe. Check that other gas appliances work, and that a propane tank is not empty.
• Power (power-vent models). Confirm the heater is plugged in and the breaker for that outlet is on. Reset a tripped breaker once only.
• The status light. Record the flash pattern before turning anything off.
• One reset or relight, as written. For a standing pilot, follow the lighting label once. For the power-vented models in the manual, a soft lockout is reset by sliding the control’s ON/OFF switch to OFF, waiting 10 seconds, and sliding it back to ON. If the same code returns, leave it off.
• Water and vapors. Do not operate a heater that has had water in the burner area. Keep gasoline, paint and solvents away. If the light shows a flammable vapor lockout, do not reset while any vapor or odor is present; the manual says the control resets only after the contamination is gone and the sensor clears, and a sensor that will not clear must be replaced.

What the technician will check

A technician confirms gas pressure and outlet polarity. On a hot-surface model they watch the full sequence, check the pressure switch, hose and vent, test what the control sends to the igniter, inspect the igniter for cracks, and check the flame sensor, since a burner that lights and then shuts down usually points there. On a standing-pilot model they check the piezo, its lead, the electrode position, and gas flow to the pilot. Igniter work on FVIR models means opening the sealed combustion chamber.

Repair or replace

A piezo igniter, hot-surface igniter, flame sensor, pressure switch or gas control is a part replacement on a heater that is otherwise sound. A leaking tank means replacement, and A. O. Smith’s labels say a gas heater that has been under water must be replaced. For other no-heat symptoms, see the pilot and ignition problems hub.

Frequently Asked Questions

Q: I see the hot-surface igniter glow, but the burner never lights. Is the igniter bad? A: Usually not. A glowing igniter is doing its job, and the control then has to open the gas valve and sense flame. A closed gas shutoff, an empty propane tank, a gas valve fault, or a flame-sensing problem is more likely. Do not keep cycling the heater; let a technician test it.

Q: Can I light my power-vent A. O. Smith or State heater with a lighter? A: No. The label on these models says they have no pilot and must not be lit by hand. Doing so can ignite gas that has collected in the combustion chamber.

Q: The piezo clicks but I cannot see a spark. What now? A: Dim the room lights and look through the viewport while pressing it. If there is still no spark, the piezo, its wire or electrode needs a technician. Use a match only if your heater’s label allows it.