Lighting the Pilot Light: The Basic Steps

To turn on a pilot light on a gas heater, you will locate the control knob (usually on the front or side of the heater), set it to the "Pilot" position, press and hold the knob inward, and hold a lit match or lighter to the pilot opening until the small flame ignites. Once lit, keep holding the knob for 30 to 60 seconds after the flame appears, then release it and turn the knob to "On" or "Heat".

The pilot light is a small, continuous flame that ignites the main burner when your heater calls for heat. If it has gone out—from a draft, a broken thermocouple, or straightforward age—you can relight it yourself in most cases. The whole process takes about five minutes and requires only a match or lighter.

Key Takeaways

  • The control knob has three positions: "Pilot," "On," and usually "Off"—always start at "Pilot" to avoid gas buildup.
  • You must press and hold the knob inward while lighting; this opens the gas valve to the pilot burner.
  • Hold a flame to the pilot opening (a small metal tube near the control knob) until you see a blue flame appear.
  • Keep the knob pressed for 30 to 60 seconds after ignition so the thermocouple heats up and keeps the valve open.
  • If the pilot will not stay lit after three attempts, the thermocouple or gas valve may need replacement by a technician.

Locate the Control Knob and Pilot Opening

Open the access panel or door on the front of your heater. You will see a control knob, usually labeled with positions for "Off," "Pilot," and "On" (or sometimes "Heat"). The knob is typically brass or metal and sits on the gas valve itself. Next to or below the knob, you will see a small metal tube or opening—this is the pilot burner opening where the flame comes out.

If you cannot find the pilot opening, check your heater's manual or look for a small brass fitting with a tiny hole. Some heaters have the pilot opening recessed slightly into the burner assembly. You may need a flashlight to see it clearly, especially if the heater is in a dark corner or basement.

Set the Knob to Pilot and Press Inward

Turn the control knob clockwise or counterclockwise (depending on your model) until it points to "Pilot." This position allows gas to flow only to the small pilot burner, not the main burner. Once the knob is set to "Pilot," press it inward firmly and hold it down. You should feel resistance—this is normal and means the valve is opening.

Do not release the knob yet. Keeping it pressed is essential because it holds the gas valve open so fuel can reach the pilot burner. If you let go before the pilot is lit, the gas will stop flowing and you will have to start over.

Light the Pilot Burner with a Match or Lighter

While holding the knob inward, bring a lit match or lighter to the pilot opening. You may need to angle the flame slightly into the opening to reach the gas. Hold the flame there for a few seconds. You should see a small blue flame ignite at the pilot opening—this is the pilot light.

If the flame does not appear after five seconds, remove the match and wait a few seconds for any gas to clear. Then try again. Do not hold the flame in place for more than 10 seconds on each attempt, as this wastes fuel and can be unsafe. If you are using a long lighter (the kind for grills or candles), it is easier to reach the opening than with a short match.

Hold the Knob Down to Let the Thermocouple Heat Up

Once the pilot flame is lit, continue holding the knob inward for another 30 to 60 seconds. During this time, the thermocouple—a heat-sensing device near the pilot flame—is warming up. The thermocouple tells the gas valve to stay open even after you release the knob. If you let go too soon, the valve will close and the pilot will go out.

Watch the pilot flame while you hold the knob. It should be steady and blue. If it flickers or goes out while you are still holding the knob, the gas may not be flowing properly, or there may be a draft. Wait a moment and try lighting it again.

Release the Knob and Turn It to On

After 30 to 60 seconds, slowly release the knob. The pilot flame should stay lit. If it goes out when ready, press the knob back in and hold it for another 30 seconds—the thermocouple may not have heated enough. Once the pilot stays lit after you release the knob, turn the control knob to "On" or "Heat." The main burner should ignite within a few seconds, and you will hear a whoosh as the larger flame comes to life.

If the main burner does not ignite, turn the knob back to "Pilot" and wait a minute. Then try turning it to "On" again. Sometimes the thermocouple needs a bit more time to fully warm up.

What to Do If the Pilot Will Not Stay Lit

If the pilot light goes out as soon as you release the knob, or if it will not light at all after three careful attempts, the problem is usually the thermocouple or the gas valve. The thermocouple may be bent, dirty, or worn out and no longer sensing the heat from the pilot flame. A dirty thermocouple can sometimes be cleaned gently with fine sandpaper or a soft cloth, but replacement is more reliable.

If you smell gas while trying to light the pilot, stop when ready, turn the knob to "Off," open windows or doors to ventilate, and leave the heater alone for at least five minutes. Do not attempt to light it again. Call a may have access to technician or your gas company's emergency line. A persistent gas smell means the valve is not closing properly, which is a safety issue.

Frequently Asked Questions

How long should I hold the knob down after the pilot lights?

Hold it for 30 to 60 seconds. This gives the thermocouple time to heat up and signal the gas valve to stay open. If you are unsure, 45 seconds is a safe middle ground. Holding it longer does not hurt, but shorter than 30 seconds often results in the pilot going out.

What if I smell gas but do not see a flame?

Turn the knob to "Off" when ready and do not try again. Open windows and doors to let gas escape. Wait at least five minutes before approaching the heater again. A gas smell without a flame means fuel is leaking into the heater box, which is unsafe. Contact a technician or your gas company.

Can I use a lighter instead of a match?

Yes. A long-reach lighter (like a grill lighter) is actually easier to use than a match because you can hold it at a safer distance from the heater. A regular short lighter works too, but you have to get your hand closer to the pilot opening. Avoid lighters with very thin flames, as they can be hard to see in the heater's dim interior.

Why does the pilot light keep going out?

The most common cause is a worn or dirty thermocouple that is no longer holding the gas valve open. A draft blowing across the pilot opening can also extinguish it. If your heater is in a drafty basement or near a door, try closing the door or blocking the draft. If the pilot still will not stay lit, the thermocouple or valve needs replacement by a technician.

Do I need to turn off the heater before relighting the pilot?

No, but it is safer to do so. If the heater is currently running, turn the control knob to "Off" first, wait a minute for any residual gas to clear, then proceed with lighting the pilot. This prevents gas from building up in the heater box while you are working.