The basic steps to relight your pilot

To light a hot water heater pilot light, you need to locate the pilot assembly at the bottom of the tank, turn the gas control knob to the "Pilot" position, hold down the ignition button while holding a lit match or lighter to the pilot opening, and keep the button pressed for 30 to 60 seconds after the flame catches. Once the pilot stays lit on its own, turn the gas control knob back to "On" or the desired temperature setting.

The exact location and appearance of these controls varies by manufacturer and model year. Some heaters have a piezo igniter button (a spark-producing button you press) instead of requiring an external flame. Others have an electronic ignition system that lights automatically when you turn the knob. Check your heater's label or manual to confirm which type you have before you start.

Key Takeaways

  • The pilot light assembly is always at the bottom of the tank, behind a small access panel or door that you may need to remove.
  • The gas control knob has three positions: "Pilot," "On," and usually a temperature setting, and you must turn it to "Pilot" before attempting to light.
  • You need either a match, lighter, or a working piezo igniter button depending on your heater model.
  • After the pilot flame catches, hold the ignition button down for 30 to 60 seconds so the thermocouple heats up and keeps the gas valve open.
  • If the pilot will not stay lit after three attempts, the thermocouple may be faulty and need replacement by a technician.

Finding the pilot light assembly on your tank

The pilot assembly sits at the very bottom of your water heater, usually inside a small chamber or behind a removable panel. On gas heaters, you will see a metal tube running down from the main burner area — this is the pilot tube. At the bottom of this tube is a small opening where the pilot flame burns.

Look for a metal box or shroud at the base of the tank. Some models have a hinged door you swing open; others have a removable cover held by one or two screws. If you cannot see the pilot opening clearly, use a flashlight. The opening itself is tiny — roughly the size of a pencil tip — and you may see a small electrode or spark rod next to it if your heater has electronic ignition.

Understanding the gas control knob positions

The gas control knob is a dial or lever mounted on the side of the heater's control box, usually near the bottom. It has at least three positions: "Pilot," "On," and a temperature or heat setting (often marked with numbers or "High," "Medium," "Low").

Turn the knob all the way to "Pilot" — this position allows gas to flow only to the pilot burner, not the main burner. If you skip this step and turn the knob directly to "On," you risk flooding the combustion chamber with gas and creating a safety hazard. Always start at "Pilot."

Lighting the pilot with a match or lighter

Once the knob is set to "Pilot," hold down the ignition button (usually a red or black button on the control box) and bring a lit match or lighter to the pilot opening. You may need to angle the flame slightly to reach the opening. Keep the button pressed down continuously — do not release it yet.

You should see a small blue flame appear at the pilot opening within a few seconds. If the flame does not appear after 10 seconds, release the button, wait a minute for any gas to clear, and try again. Do not hold the button down for more than 30 seconds on the first attempt, as this can flood the chamber with unburned gas.

Once the pilot flame is burning steadily, keep the ignition button pressed for another 30 to 60 seconds. This allows the thermocouple (a heat-sensing device next to the flame) to warm up. The thermocouple tells the gas valve to stay open and keep supplying gas to the pilot. If you release the button too soon, the pilot will go out when ready.

Using a piezo igniter instead of a match

Some water heaters have a piezo igniter button built into the control box. This button creates a spark when you press it, eliminating the need for a match or lighter. To use it, turn the gas control knob to "Pilot," then press and hold the piezo button while watching the pilot opening.

You should see a spark and hear a clicking sound. The pilot flame should ignite within a few seconds. Keep holding the button for 30 to 60 seconds after the flame appears, just as you would with a match. If the spark is weak or produces no flame after three attempts, the piezo element may be worn out and the heater may need service.

What to do if the pilot will not stay lit

If the pilot lights but goes out as soon as you release the ignition button, the thermocouple is likely faulty. The thermocouple is a thin metal rod that sits in the pilot flame and generates a small electrical signal when heated. If it is not working, the gas valve closes automatically for safety reasons.

Try lighting the pilot two more times to rule out user error. If it fails all three times, the thermocouple needs replacement. This is a job for a licensed technician — the part itself costs $15 to $30, but labor and service calls typically run $150 to $300 depending on your location and the heater model.

Other reasons the pilot may not stay lit include a clogged pilot opening (debris or corrosion blocking the gas flow) or a faulty gas control valve. A technician can clean the opening or test the valve to determine which is the problem.

Turning the heater back to normal operation

Once the pilot flame is burning steadily and you have held the ignition button for the full 30 to 60 seconds, release the button. The pilot should continue burning on its own. Now turn the gas control knob from "Pilot" to "On" or to your desired temperature setting (usually marked with numbers or heat levels).

You should hear a soft whoosh as the main burner ignites. The burner flame is much larger than the pilot flame and burns blue with perhaps a small yellow tip. If the main burner does not light within 10 seconds, turn the knob back to "Off," wait a minute, and try the pilot lighting process again.

Safety reminders before you start

Never attempt to light a pilot if you smell gas in the room. Leave the area when ready, open windows and doors, and call your gas company's emergency line. Do not use any electrical switches, lighters, or matches — a spark could ignite the gas.

If you have recently had work done on your heater or if the pilot has been out for more than a few hours, let any accumulated gas clear before lighting. Turn the knob to "Off" and wait five minutes with the area ventilated. Keep children and pets away from the heater while you are working on it, and never leave the access panel off the heater unattended.

Frequently Asked Questions

How long should I hold the ignition button down?

Hold it for 30 to 60 seconds after the pilot flame appears. This gives the thermocouple time to heat up and signal the gas valve to stay open. If you release too soon, the pilot will go out. If you hold it longer, no harm is done — just release once you are confident the flame is steady.

What if I cannot reach the pilot opening with a match?

Use a long lighter or a fireplace match instead of a short match. You can also light a piece of rolled paper or a thin stick and use that to reach the opening. Some people use a grill lighter with a long nozzle. The goal is straightforward to get a flame to the pilot opening while you hold the ignition button.

Can I light the pilot if the power is out?

Yes, if your heater has a piezo igniter or if you use a match. Electronic ignition systems require power and will not work during an outage. If your heater has electronic ignition only, you will need to wait for power to be restored or call a technician who can light it manually.

How often do pilot lights go out?

A healthy pilot light should stay lit indefinitely. If your pilot goes out once a month or more often, the thermocouple is likely failing, or there is a draft blowing the flame out. Have a technician inspect the heater to find the cause.

Is it normal for the pilot flame to be blue?

Yes. A blue pilot flame means the gas is burning cleanly with enough oxygen. A yellow or orange flame suggests incomplete combustion and may indicate a problem with the burner or air intake. If the flame is not blue, have the heater serviced.