How to Light a Water Heater Pilot Light
No hot water and the pilot is out? You can relight it yourself in about 10 minutes — but the safety check comes first. This guide covers every step, plus what to do if the pilot won't stay lit.
If you smell rotten eggs or sulfur near the water heater: Do NOT light anything. Do NOT flip light switches. Leave the building immediately. Call 911 and your gas company from outside. A gas smell means there is a gas leak — this is a fire and explosion hazard.
If there is no smell: The steps below are safe to follow. Gas water heater pilot relighting is a standard homeowner task — manufacturers design the controls specifically for this.
Does This Apply to Your Water Heater?
Step-by-Step: Relighting the Pilot
Safety check — sniff for gas
Stand near the water heater and take a moment to smell the air. Natural gas has no odor, but gas companies add mercaptan — a compound that smells like rotten eggs or sulfur — so you can detect leaks. If you smell anything like this, stop and call your gas company immediately. If there is no smell, proceed to the next step.
Turn gas control knob to OFF — wait 5 minutes
Find the gas control valve (large knob on the front labeled PILOT / ON / OFF). Turn it all the way to OFF. Wait a full 5 minutes — do not skip this. This lets any accumulated gas in the combustion chamber dissipate safely before you introduce any ignition source.
Set temperature to LOW, turn to PILOT
Turn the temperature dial to its lowest setting. Then turn the main gas control knob to the PILOT position.
Remove the access panel and find the pilot
Remove the small access panel at the bottom of the heater (usually snaps off or has two screws). Shine a flashlight inside. You will see a small burner assembly and a thin copper rod (the thermocouple) next to a tiny nozzle — that nozzle is the pilot. Note whether your heater has a separate red igniter button or a built-in piezo sparker in the gas control knob.
Hold knob down and ignite
This is the most important step — do all three things at once:
- Press and hold the gas control knob down in the PILOT position (this opens the pilot gas supply)
- While holding, press the igniter button repeatedly until the pilot lights, OR hold a long lighter or lit match directly to the pilot nozzle
- Once you see a small blue flame, keep holding the knob depressed for 30–60 seconds
Release the knob — verify pilot stays lit
Slowly release the gas control knob. The pilot flame should stay lit. If it goes out: wait 5 minutes and try again — this time hold the knob for a full 60 seconds. If the pilot still will not stay lit after 2–3 attempts, the thermocouple needs to be replaced (see below).
If the pilot stays lit: turn the control knob from PILOT to ON. Set the temperature to 120°F (the "Hot" setting). Hot water will return within 30–60 minutes.
Pilot Lights But Won't Stay Lit? Thermocouple Is the Cause
If the pilot lights when you hold the button but goes out when you let go, the thermocouple is worn out. It is no longer generating enough voltage to keep the gas valve open.
- Turn the gas control to OFF and wait 15 minutes
- Unscrew the thermocouple from the gas control valve (usually hand-tight or one small nut)
- Pull the rod out of the clip that holds it in the pilot flame
- Take it to the hardware store and buy a universal replacement ($10–$20)
- Install in reverse order — same clip position, same screw connection
- Relight the pilot following steps 2–6 above
When to Call a Professional
- You smell gas at any point — leave the building and call 911 and the gas company
- Pilot won't light after 3 attempts with a brand new thermocouple — the gas control valve may be failing
- Water heater is 10+ years old and has repeated pilot problems — it may be time to replace the unit
- You see rust-colored hot water, hear rumbling from the tank, or see water pooling at the base
- The flue pipe (exhaust pipe on top) is disconnected, corroded, or missing sections
Frequently Asked Questions
Why does my pilot light keep going out?
The most common cause is a worn thermocouple. After 5–10 years of use, the thermocouple generates too little voltage to hold the gas valve open. A replacement thermocouple costs $10–$20 and takes about 30 minutes to install. Other causes include a strong draft near the heater or a dirty pilot orifice.
Is it safe to relight a water heater pilot yourself?
Yes, if you smell no gas. The safety steps (turning to OFF and waiting 5 minutes before lighting) are designed to make this safe for homeowners. Gas appliance manufacturers print these instructions on the heater itself. If you smell rotten eggs or sulfur at any point, stop immediately and call your gas company.
What does the thermocouple do?
The thermocouple is a safety device. It sits in the pilot flame and generates about 30 millivolts of electricity when heated. That signal keeps the gas control valve open. If the pilot goes out, the thermocouple cools within seconds, the voltage drops to zero, and the gas valve closes — stopping gas flow automatically. This prevents raw gas from accumulating in the combustion chamber.
When should I replace my water heater instead of fixing the pilot?
If your water heater is 10–12+ years old and experiencing repeated pilot problems, the thermocouple may just be the first sign of end-of-life failure. Other replacement indicators: rust-colored hot water, popping or rumbling sounds (sediment), or water pooling at the base (tank is leaking — cannot be repaired). A new water heater costs $900–$1,800 installed.
Still No Hot Water After Following These Steps?
A failed gas control valve or a water heater that's past its prime needs a licensed plumber. Find one near you — most can come same day.
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How do I light a water heater pilot light in Michigan?⌄
Turn the gas control knob to PILOT, press and hold it down, use a lighter or piezo igniter to light the pilot burner, hold the knob for 30–60 seconds after ignition, then release and turn to your desired temperature setting. If the pilot will not stay lit, the thermocouple likely needs replacement — a $20–$40 part a plumber can install in under an hour.