Pilot, hot surface igniter and thermocouple compared
The part that fails depends on how your heater lights its burner.
| Part | What it does | Failure sign |
|---|---|---|
| Standing pilot flame | A small flame stays lit and ignites the burner on demand | Pilot goes out, or will not stay lit after relighting |
| Thermocouple or thermopile | A sensor that proves the pilot is lit and holds the gas valve open | Pilot lights while you hold the button, then goes out when released |
| Hot surface igniter | An electrically heated element that glows and lights the burner | No glow, a cracked element, or glow with no flame |
| Flame sensor | Confirms burner flame on electronic models | Burner lights, then shuts off after a few seconds |
Check the label on the heater or the owner's manual to see which system you have.
Reading the symptoms before you replace anything
Start with what the heater does. A pilot that will not stay lit usually blames the thermocouple, a draft or a dirty pilot tube. A heater with a glowing igniter that never lights the burner may have a weak gas valve or a blocked burner.
A heater with no glow at all and a dead display may have an electrical or control board issue instead of a bad igniter. The more you can tell the plumber about the behavior, the fewer parts are guessed at.
Do not buy a part first. A new thermocouple will not fix a bad gas control, and a cracked igniter can be misdiagnosed if the real fault is a blocked vent.
If you smell gas, the order of calls changes
A rotten egg odor near a water heater means gas may be escaping. Do not flip switches, use a lighter or try to relight the pilot. Leave the building with everyone inside, then call the gas utility or 911 from outside.
Call the plumber only after the gas utility says the area is safe. We do not promise a response time for gas calls, because the utility has to clear the building first. Never attempt to repair a gas control or fitting yourself.
What moves the igniter replacement price
A published range gives a sense of the market, but the number you pay depends on a few details the plumber confirms on site.
What you can check yourself and where to stop
These checks are safe on most heaters. Stop at any step that involves gas fittings or wiring.
- Smell the room first. If you detect gas at any point, stop and follow the gas safety rule above.
- Check the thermostat dial. Make sure it is set to a heating temperature, not to Off or Vacation.
- Look at the display or window. Many heaters flash codes. Write down what you see, since that helps the plumber.
- Check the breaker or outlet. Electronic ignition units need power. Reset a tripped breaker only once.
- Relight the pilot only as the label says. Follow the instructions printed on the heater, and stop if it will not stay lit after one or two tries.
- Call if parts or gas are involved. Replacing an igniter means working near the gas valve and burner. Our water heater repair team does this work.
Why the igniter fails and when scale plays a part
Hot surface igniters are brittle ceramic or silicon carbide elements. They crack from vibration, age and repeated heat cycles. A gentle bump while cleaning can break one.
Scale does not damage the igniter directly. But hard water leaves mineral buildup on the tank bottom, which makes the burner run longer and can lead to overheating, according to hard water references. A heater that runs hot and long wears all of its parts faster.
If the heater is more than a decade old and also leaks or rumbles, ask whether replacement is the better value.
Colton permit and water facts for a heater fix
The City of Colton's Building Division issues water heater permits for replacements. A change-out at the same location gets one final inspection, and a new location gets rough plumbing and final inspections. Converting from gas to electric is not allowed under the alteration path. If your igniter repair turns into a replacement, ask the Division about permits first.
Colton's water averages near 207 mg/L total hardness in the City's 2024 water report, which is very hard on the USGS scale. If your tank has not been flushed in years, ask the plumber to check for sediment while the burner is open. Draining a tank is general trade practice, and we do not give a Colton schedule for it.
The Building Division is at 659 North La Cadena Drive. Ask the Division which California Plumbing Code edition applies to your job.
When to replace the heater instead of the igniter
An igniter on a young heater is a good repair. On an older tank that also shows rust at the base, rumbling or a leaking fitting, the repair may buy only a short stretch. A tech can check the burner chamber, anode and tank bottom while the access panel is off.
If you decide to replace, our water heater replacement service covers removal and permit steps. Neighbors in Grand Terrace and Loma Linda can book the same way.
Frequently asked questions
A failed igniter usually means the burner stays off, which is a nuisance, not a hazard. The danger comes from trying to light a gas heater with a bad gas valve or when gas is present.
If you smell gas, leave and call the gas utility or 911.
Some homeowners do, but it means working near the gas valve and burner chamber. A wrong part or a damaged seal creates a gas leak risk. We recommend a licensed plumber.
It varies by model, heat cycles and water quality, so we do not give a number. Cracking and glowing weakly are signs it is near the end.
On a standing pilot heater, that points more to the thermocouple, a draft or a dirty pilot tube. A hot surface igniter model has no pilot flame.
The City page we checked covers water heater replacement permits. It does not list igniter repairs. Ask the City of Colton Building Division whether your specific work needs one.
Replace when repairs approach the cost of a new unit, the tank leaks, or the tank shows rust. A leaking tank cannot be repaired.