Water Heater Piezo Igniter Won't Spark: Causes
On this page (5 sections)
The Short Answer: A piezo igniter is the push button that makes a spark at the pilot on standing-pilot gas heaters. If it does not click, the button or crystal has usually failed. If it clicks but no spark appears at the pilot, the wire, electrode, or gap is the usual problem, often after moisture. If it sparks but the pilot does not light, the igniter is fine and the cause is gas reaching the pilot.
Click, spark, flame: which one is missing?
| What happens when you press the button | Likely cause | Who fixes it |
|---|---|---|
| No click, button feels loose or stuck | Failed piezo button | Technician replaces the igniter |
| Click, but no spark visible through the sight glass | Wire disconnected, cracked electrode, wet electrode, or spark gap out of position | Technician |
| Spark jumps somewhere other than the pilot | Cracked insulator or damaged wire | Technician |
| Bright spark at the pilot but no flame | Knob not on PILOT or not held down, gas valve closed, clogged pilot orifice, or no gas | Check gas steps below |
| Pilot lights but goes out when you release the knob | Thermocouple or thermopile problem, not the igniter | See why a gas water heater won’t stay lit |
On sealed flammable-vapor-resistant (FVIR) tanks, the spark can be hard to see through the sight glass in a bright room. Dimming the lights can help.
Make sure it is a piezo
The steps here are for standing-pilot heaters, where you hold the gas knob on PILOT and press a separate button. Heaters with electronic ignition (no button, an automatic clicking sound, or a status light) and power-vent models work differently; see water heater burner not lighting.
What you can check safely
- Follow the lighting label exactly. Many controls require the knob to be pushed in and held on PILOT while you press the igniter. Pressing the button without the knob held down produces a spark but no gas.
- Confirm the gas supply: the shutoff valve on the heater’s gas pipe is open (handle in line with the pipe), and other gas appliances work.
- Wait the time on the label after any failed attempt before trying again, so unburned gas can clear.
- Check for water: drips from above, a damp floor, or rust near the burner area can mean the electrode got wet. See water dripping on the pilot light.
- Try a few presses, not dozens. If there is still no spark, stop.
Some lighting labels describe lighting with a long match or lighter through a port when the igniter fails. Only do this if your heater’s label specifically includes that method; sealed FVIR tanks generally do not allow it.
What the technician will check
A technician inspects the igniter wire and its connection, the electrode’s ceramic insulator for cracks, and the spark position relative to the pilot hood. The piezo button and the electrode are inexpensive parts, but on FVIR tanks the electrode is part of the pilot assembly inside the sealed combustion chamber, so replacing it means removing and resealing the inner door. Many technicians replace the whole pilot assembly (pilot, thermocouple or thermopile, and electrode) as one part; see replace a water heater pilot assembly.
Frequently Asked Questions
Q: Can I replace the piezo button myself? A: On some heaters the button snaps into a bracket outside the combustion chamber, but the wire runs to an electrode inside the sealed chamber. Because the sealed chamber is a safety feature on FVIR tanks, have a technician handle it.
Q: The igniter sparks and I smell a little gas but the pilot doesn’t light. What now? A: Stop. Turn the control to OFF and leave the area to let gas clear. A strong or lingering gas smell means leave the building and call the utility. A spark with no flame usually means the pilot orifice or supply needs attention by a technician.
Manuals and supporting references
These links distinguish general safety information from model-specific documentation. A manual directory helps you locate your unit’s instructions; it does not establish that every model uses the same parts, codes, or test values.
- PG&E: recognizing and responding to a gas leak (opens in a new tab)Emergency actions for suspected fuel-gas leaks.
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