The basic steps to relight a pilot light

To relight your gas water heater pilot light, you will 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 gas control knob back to "On" or the desired temperature setting.

The whole process usually takes less than five minutes. If the pilot does not stay lit after you release the button, wait five minutes for the gas to clear, then try again. Most pilot lights relight on the first or second attempt.

Key Takeaways

  • Turn the gas control knob to "Pilot" before attempting to light the pilot, or you risk gas buildup in the combustion chamber.
  • Hold the ignition button down for 30 to 60 seconds after the flame appears so the thermocouple heats up enough to keep the gas valve open.
  • If the pilot will not stay lit after three attempts, wait 10 minutes and check that the gas supply valve (the one on the gas line itself) is fully open.
  • If the pilot still will not light, the thermocouple or igniter may be faulty and you will need to call a technician.

Locate the pilot light assembly and gas control knob

Open the access panel on the front or side of your water heater. You will see a small burner opening near the bottom of the tank — this is where the pilot light burns. Just above or beside it is the gas control knob, which usually has three positions: "Pilot," "On," and sometimes a temperature setting or "Off."

Before you do anything, look at the gas supply valve on the gas line coming into the heater. It should be parallel to the pipe (pointing in the same direction as the gas flow). If it is perpendicular to the pipe, the gas supply is shut off — turn it parallel first, then wait two minutes before proceeding.

Set the knob to Pilot and prepare to ignite

Turn the gas control knob to the "Pilot" position. This setting allows gas to flow only to the pilot burner, not to the main burner, so you will not accidentally fill the combustion chamber with gas while you are lighting.

Gather a long lighter or long matches — you need the flame to reach into the pilot opening without your hand getting close to the heat. A barbecue lighter or long fireplace match works well. Do not use a short match or regular lighter; you risk burning your hand or not reaching the opening.

Light the pilot and hold the ignition button

Press and hold the ignition button (usually red or black, located on the control knob itself or nearby). While holding it down, bring the lit match or lighter flame to the pilot burner opening. You should see a small blue flame ignite within a few seconds.

Keep holding the ignition button down for 30 to 60 seconds after the flame appears. This allows the thermocouple — a heat-sensing device next to the pilot flame — to warm up enough to signal the gas valve to stay open. If you release the button too soon, the pilot will go out.

After 30 to 60 seconds, slowly release the button while watching the pilot flame. If it stays lit, you have succeeded. If it goes out when ready, wait five minutes for any residual gas to clear, then repeat the process.

Turn the knob back to On and check the main burner

Once the pilot is burning steadily, turn the gas control knob from "Pilot" to "On" or to your desired temperature setting (usually marked in degrees Fahrenheit). The main burner should ignite within a few seconds, producing a larger blue flame below the pilot.

Listen for the ignition click and watch for the main flame. If the main burner does not light, turn the knob back to "Off," wait a minute, and try again. If it still does not light after two attempts, the thermocouple may not be making good contact with the pilot flame — see the troubleshooting section below.

What to do if the pilot will not stay lit

If the pilot light goes out as soon as you release the ignition button, the thermocouple is not getting hot enough. This usually means you did not hold the button long enough. Try again, but this time hold the button for a full 60 seconds before releasing it slowly.

If the pilot still will not stay lit after three attempts, check that the gas supply valve on the gas line is fully open (handle parallel to the pipe). If it is open and the pilot still will not light, the thermocouple may be dirty or faulty. At this point, call a licensed technician — replacing a thermocouple requires disconnecting gas lines and should not be attempted without proper training.

If you smell gas at any point during this process, stop when ready, turn the gas control knob to "Off," open windows to ventilate, and leave the house. Do not use electrical switches or create sparks. Call your gas company's emergency line from outside.

When to call a professional

If the pilot light will not ignite at all after you have held a flame to the opening for 10 seconds, the igniter or gas supply to the pilot may be blocked. If the pilot lights but the main burner will not ignite, the thermocouple is likely faulty. If you smell rotten eggs (the smell added to natural gas), there is a gas leak — leave the house and call your gas company when ready.

A technician can clean or replace the thermocouple, clear a blocked pilot opening, or diagnose a faulty igniter in about an hour. This is not a repair you should attempt yourself, as it involves disconnecting gas lines and handling components that can be damaged by improper handling.

Frequently Asked Questions

How long should I hold the ignition button down?

Hold it for 30 to 60 seconds after the pilot flame appears. The longer you hold it, the hotter the thermocouple gets, and the more reliably the gas valve will stay open. If you release too soon, the pilot will go out as soon as you let go of the button.

What if I smell gas while trying to light the pilot?

Turn the gas control knob to "Off" when ready. Open windows and doors to ventilate the room. Do not use electrical switches, lighters, or anything that could create a spark. Leave the house and call your gas company's emergency line from outside. Do not re-enter until they have checked for a leak.

Can I use a regular match instead of a long lighter?

A regular match will work if you can reach the pilot opening safely, but a long lighter or long fireplace match is safer because it keeps your hand farther from the heat. The pilot flame can be hot enough to burn you if your hand gets too close.

How many times should I try before calling a technician?

Try three times, waiting five minutes between attempts to let gas clear. If the pilot will not stay lit after three attempts, or if it will not light at all after 10 seconds of flame exposure, the thermocouple or igniter is likely faulty and needs professional service.

Should the pilot flame be blue or orange?

A healthy pilot flame is mostly blue with a small yellow tip. If the flame is mostly yellow or orange, the pilot opening may be dirty. A technician can clean it, but do not attempt this yourself — the opening is small and easily damaged.