The basic steps to relight your pilot
To light the pilot on a gas water heater, turn the gas control knob to the Pilot position, hold down the ignition button while holding a lit match or lighter to the pilot burner opening, and keep the button pressed for 30 to 60 seconds after the flame appears. Once the pilot stays lit on its own, turn the knob back to On or your desired temperature setting.
The pilot burner is a small opening near the bottom of the water heater, usually inside a metal tube or chamber. You will see it clearly once you remove the access panel at the front of the tank. The whole process takes less than five minutes if the gas is flowing and the ignition works.
If the pilot will not stay lit after you release the button, or if you smell gas but see no flame, stop and read the troubleshooting section below. A pilot that will not hold is usually a sign the thermocouple (a safety sensor) needs replacement, which is a job for a licensed technician.
Key Takeaways
- Turn the gas control knob to Pilot, press the ignition button, and hold a flame to the pilot opening for 30 to 60 seconds.
- The pilot burner is a small opening at the bottom of the tank, visible once you open the front access panel.
- If the pilot lights but will not stay on after you release the button, the thermocouple likely needs replacement by a professional.
- If you smell gas but see no flame, turn the knob to Off, wait five minutes for gas to clear, and try again—if it still fails, call a technician.
- Never force the ignition button or hold it down longer than 60 seconds, as this can flood the burner chamber with gas.
Locating the pilot burner and access panel
Open the front access panel of your water heater by unlatching or unscrewing the metal cover at the base of the tank. Behind it you will see the burner chamber, and the pilot opening is a small hole or tube pointing downward into that chamber. The gas control knob is mounted on the outside of the tank, usually near the bottom, and will have three or four positions marked: Off, Pilot, On, and sometimes a temperature dial.
Before you touch anything, make sure the area is well-ventilated and that you have a working lighter or long matches on hand. A standard kitchen lighter works better than short matches because it keeps your hand farther from the flame. If you cannot see the pilot opening clearly, use a flashlight to look into the chamber—do not lean your face directly over the opening.
What to do if the pilot will not light
If you hold a flame to the pilot opening and nothing ignites, the most common cause is that gas is not reaching the burner. Turn the knob to Off, wait five minutes for any gas in the chamber to clear, and try again. If the pilot still does not light, check that the gas supply valve on the line leading into the water heater is fully open—it should be parallel to the pipe, not perpendicular to it.
If gas is flowing but the pilot still will not ignite, the pilot opening may be clogged with dust or debris. Turn the knob to Off and use a straightened paper clip or thin wire to gently clear the opening. Do not use excessive force, as the opening is small and easily damaged. Try lighting again after clearing.
If you smell gas strongly but still see no flame after two or three attempts, turn the knob to Off and do not try again. Open windows and doors to ventilate, leave the house, and call a licensed technician or your gas company's emergency line. A gas leak or failed ignition system requires professional diagnosis.
Why the pilot goes out and will not relight
The most common reason a pilot lights but then goes out when you release the ignition button is a faulty thermocouple—a thin metal rod that sits in the pilot flame and tells the gas valve to stay open. When the thermocouple fails, the valve closes automatically as a safety measure, shutting off gas to the pilot. This is not something you can fix yourself; a technician will need to replace the thermocouple, which is an inexpensive part but requires removing it from inside the burner chamber.
A second reason is that the pilot flame is too weak to heat the thermocouple properly. This can happen if the pilot opening is partially blocked or if the gas pressure is low. Clearing the opening (as described above) may solve it. If the flame looks normal in size but still will not hold, the thermocouple is the likely culprit.
Drafts from nearby doors or windows can also blow out a weak pilot flame. If your water heater is in a garage or basement with frequent air movement, try lighting the pilot again on a calmer day, or ask a technician to check whether the pilot opening needs adjustment.
Safety steps to follow every time
Never hold the ignition button down for longer than 60 seconds. Holding it longer floods the burner chamber with gas, which can create a hazard when the flame finally ignites. If the pilot has not lit within 60 seconds, release the button, turn the knob to Off, wait five minutes, and try again.
Always make sure the area around the water heater is clear of flammable materials—paper, cardboard, cleaning supplies, and cloth should be at least three feet away. Gas water heaters produce heat and flame, and the space around them needs to stay clear for safety and proper ventilation.
If you smell gas at any point and are unsure whether it is coming from the water heater, leave the house and call your gas company's emergency line. Natural gas has a distinctive rotten-egg smell added to it for safety, and any strong smell warrants professional attention. Do not try to locate the source yourself or light matches to test for gas.
When to call a professional instead
Call a licensed technician if the pilot lights but will not stay on after you release the ignition button, even after you have tried the process two or three times. This almost always means the thermocouple needs replacement, which requires opening the burner assembly and is not a homeowner task.
Also call a professional if you smell gas but cannot get the pilot to light, if the ignition button does not click or feel like it is working, or if you see water pooling around the base of the tank. These are signs of a gas leak, a failed ignition system, or a tank problem that requires diagnosis by someone trained on your specific model.
If your water heater is still under warranty, check the manual before attempting to light the pilot yourself—some warranties require a technician to perform this work. Most water heater warranties last five to ten years from the date of installation.
Frequently Asked Questions
How long should I hold the ignition button down?
Hold it for 30 to 60 seconds after the pilot flame appears. You are giving the thermocouple time to heat up and signal the gas valve to stay open. Once you see a steady flame, keep the button pressed for another 30 seconds, then release it slowly. If the flame goes out when ready, the thermocouple is likely faulty.
Can I use any kind of lighter to light the pilot?
A long-reach lighter or long matches work best because they keep your hand away from the flame and the hot burner chamber. A standard kitchen lighter works fine. Avoid short matches that force your hand close to the opening. Never use a candle or anything that could drip wax into the chamber.
What does it mean if the pilot flame is very small or blue instead of yellow?
A small blue flame is usually normal and means the gas is burning cleanly. A yellow or orange flame can mean the opening is partially blocked or the air-to-gas ratio is off, but it is not always a sign of danger. If the flame is so small you can barely see it, the pilot opening may be clogged and should be cleared with a thin wire.
Is it safe to light the pilot myself, or should I always call a technician?
Lighting the pilot yourself is safe if you follow the steps carefully and stop when ready if you smell gas or the pilot will not light. It is a routine maintenance task that most homeowners can do. However, if the pilot will not stay lit, or if you are uncomfortable working with gas appliances, calling a technician is the right choice.
How often do I need to relight the pilot?
Under normal conditions, the pilot should stay lit continuously and you should never need to relight it. If the pilot goes out regularly, something is wrong—usually a faulty thermocouple, a gas supply issue, or a draft problem. A pilot that goes out more than once a year is a sign to call a technician for diagnosis.