The basic steps to relight your pilot light
To light a pilot light on a gas water heater, you will turn the gas control knob to the "Pilot" position, hold a lit match or lighter near the pilot burner opening at the bottom of the heater, and press the ignition button (or knob) while the flame is close. The pilot light should catch within a few seconds. Once it is lit, keep holding the button for 30 to 60 seconds so the thermocouple—a safety sensor—warms up and stays open. Then turn the gas control knob to "On" or the desired temperature setting.
The whole process takes about two minutes. If the pilot light does not stay lit after you release the button, the thermocouple may be dirty or failing, and you will need to clean or replace it. Most pilot lights that go out are straightforward drafty or have a clogged burner, not a broken part.
Key Takeaways
- Turn the gas control knob to "Pilot," light the burner with a match or lighter while pressing the ignition button, and hold the button for 30 to 60 seconds before switching to "On."
- The pilot light opening is usually a small hole at the bottom of the water heater, often marked with a label or arrow on the access panel.
- If the pilot light goes out when ready after you release the button, the thermocouple is likely dirty and needs cleaning with a soft brush or cloth.
- A pilot light that will not light at all may indicate a gas supply problem, a clogged burner, or a faulty ignition button—check the gas valve is open before assuming the heater is broken.
Locate the pilot light burner and access panel
Open the access panel at the bottom front of your water heater. This is usually a small metal or plastic door held by one or two screws or a clip. Behind it you will see the pilot burner—a small brass or steel fitting with a tiny opening, often labeled "Pilot" with an arrow pointing to it. The gas control knob is mounted on the same panel or just above it.
Before you do anything, make sure the area is clear of loose paper, cloth, or anything flammable. Pilot lights burn at a low temperature, but you do not want to risk igniting nearby materials. If you smell gas, close the access panel, turn off the gas valve at the control knob, and wait 5 to 10 minutes for the gas to clear before trying again.
Turn the gas control knob to Pilot and prepare to ignite
Locate the gas control knob on the heater. It will have three positions: "Off," "Pilot," and "On" (or a temperature dial). Turn it clockwise to "Pilot." This setting allows gas to flow to the pilot burner only, not to the main burner, so you can light it safely without heating the tank.
Gather a long lighter or a long wooden match—a regular match or short lighter makes it hard to reach the pilot opening safely. Some water heaters have a built-in ignition button that creates a spark; others require you to use an open flame. Check your heater's label or manual to see which type you have. If you have an ignition button, you will press it while holding the flame near the pilot opening.
Light the pilot and hold the ignition button
Hold the lit match or lighter near the pilot burner opening. At the same time, press and hold the ignition button (or turn the knob if your heater uses a manual spark igniter). You should see a small blue flame appear at the pilot opening within 3 to 5 seconds. If nothing happens after 10 seconds, release the button, wait 30 seconds, and try again.
Once the pilot light is lit, keep holding the ignition button or knob for 30 to 60 seconds. This is the most important step. The thermocouple—a thin metal rod near the flame—needs time to heat up. If you release the button too soon, the thermocouple will not stay warm enough to keep the gas valve open, and the pilot will go out as soon as you let go. Count slowly to 60 to be safe.
Release the button and switch to On
After 60 seconds, slowly release the ignition button or knob. The pilot flame should stay lit. If it goes out when ready, wait a minute and repeat the process, holding the button longer this time—up to 90 seconds. A pilot that dies right away almost always means the thermocouple needs cleaning.
Once the pilot stays lit on its own, turn the gas control knob from "Pilot" to "On" or to your desired temperature setting (usually marked in degrees Fahrenheit). You should hear a soft whoosh as the main burner ignites. The water heater is now running normally. Close the access panel and wait 10 to 15 minutes for the tank to begin heating.
What to do if the pilot light will not stay lit
If the pilot light goes out within seconds of releasing the button, the thermocouple is almost certainly dirty. Turn the gas control knob back to "Off," wait 2 minutes, and then locate the thermocouple—it is a thin rod with a hollow center, positioned just to the side of the pilot flame opening. Use a soft-bristled brush, a clean cloth, or fine sandpaper to gently wipe away any soot or dust from the rod. Do not bend or damage it.
After cleaning, repeat the lighting process. If the pilot still will not hold, the thermocouple may be failing and will need to be replaced. This is a job you can do yourself if you are comfortable working with gas fittings, or you can call a plumber or water heater technician. Replacement thermocouples cost between $15 and $30 and take about 20 minutes to install.
If the pilot light will not light at all—no spark, no flame—check that the gas valve on the supply line is open (turn the handle so it is parallel to the pipe). If the valve is open and the pilot still will not light, the ignition button may be broken, or there may be a blockage in the pilot tube. These issues require professional service.
Common mistakes to avoid
Do not release the ignition button too quickly. The most common reason a pilot light goes out is that the thermocouple has not warmed up enough. Holding the button for at least 30 seconds—and up to 90 seconds on older heaters—is the single most important step.
Do not assume the heater is broken if the pilot goes out once. Drafts, a recent power outage, or a small amount of debris in the burner can cause a one-time failure. Try lighting it again before calling for service. Do not use a propane torch or any high-heat flame near the pilot opening; the intense heat can damage the thermocouple and other components. A regular match or lighter is all you need.
Do not ignore a strong gas smell. If you smell gas and the pilot will not light, or if you smell gas after the pilot is lit, turn off the gas at the control knob, leave the area, and call your gas company or a technician. A gas leak is a safety hazard and must be handled by a professional.
Frequently Asked Questions
How long should I hold the ignition button?
Hold it for at least 30 to 60 seconds after the pilot flame appears. Older heaters sometimes need 90 seconds. The button warms the thermocouple, which keeps the gas valve open. If you release too soon, the pilot will go out when you let go.
What if I do not have an ignition button?
Some older water heaters use a manual spark igniter (a knob you turn) instead of a button. Turn the knob while holding a lit match near the pilot opening. The process is the same—light the flame, hold the knob for 30 to 60 seconds, then release and switch to "On."
Can I light the pilot without a match or lighter?
No. You need an open flame or a spark. If your ignition button does not work, you must use a match or lighter. Do not try to light the pilot with anything else, and do not leave the gas on without a flame—gas will accumulate and become a safety hazard.
Why does my pilot light keep going out?
The thermocouple is almost always the cause. It collects soot and dust over time and loses the ability to sense the flame. Clean it with a soft brush or cloth. If cleaning does not work, the thermocouple is failing and needs replacement.
Is it safe to light the pilot myself?
Yes, lighting a pilot light is a safe, routine task if you follow the steps carefully. Keep the area clear of flammable materials, do not rush, and stop if you smell gas. If you are uncomfortable working with gas appliances, a plumber or technician can do it for you in about 15 minutes.