The Basic Steps to Relight Your Pilot Light

To relight a pilot light, you need to locate the control knob (usually labeled "Pilot," "On," and "Off"), turn it to the "Pilot" position, hold down the ignition button while holding a lit match or lighter to the pilot opening for 30 to 60 seconds, then release the button and turn the knob back to "On." The whole process takes about two minutes if the gas is flowing and your igniter works.

Most pilot lights stay lit on their own once you've held the flame there long enough for the thermocouple—a heat-sensing device—to warm up and signal the gas valve to stay open. If the pilot won't stay lit after you release the button, the thermocouple is likely faulty and needs replacement by a technician.

Before you start, make sure you can see what you're doing. Use a flashlight to look into the combustion chamber where the pilot flame sits. If you smell gas but see no flame, do not attempt to relight it yourself—turn off the gas, open windows, and call your service provider or a technician.

Key Takeaways

  • Turn the control knob to "Pilot," press the ignition button, and hold a flame to the pilot opening for 30 to 60 seconds until the pilot stays lit on its own.
  • If the pilot light goes out again within a few minutes of release, the thermocouple has likely failed and requires professional replacement.
  • Never attempt to relight a pilot if you smell gas but see no flame—shut off the gas and call a technician instead.
  • Most water heaters and furnaces have the control knob and pilot opening on the front or bottom of the unit, visible without removing panels.
  • A working pilot light should produce a steady blue flame about the size of your pinky fingernail; a yellow or flickering flame means the burner needs cleaning.

Locating the Pilot Light and Control Knob

On a water heater, the control knob is usually mounted on the front of the tank near the bottom, and the pilot opening is directly below or beside it. On a furnace, the knob is typically on the front of the burner assembly, and you may need to open the furnace door or access panel to see the pilot opening clearly. Some units have a small window so you can see the flame without opening anything.

Before you touch anything, read the label on your unit—most manufacturers print the relighting steps right on the tank or door. The steps are nearly always the same, but the label tells you the exact position of your knob and whether your unit has an electronic igniter button or requires a match.

Preparing to Light the Pilot

Turn the control knob all the way to "Off" and wait five minutes. This clears any gas that may have accumulated in the chamber. If you smell gas strongly after waiting, do not proceed—open windows, leave the area, and call your service provider.

Gather a long lighter or long matches before you start. A regular match works, but a long lighter or fireplace match keeps your hand farther from the flame. Have your flashlight ready so you can see the pilot opening clearly. If your unit has an electronic ignition button, make sure the batteries are fresh—a weak battery is the most common reason a pilot won't light.

Turning the Knob and Pressing the Ignition Button

Turn the control knob to the "Pilot" position. This position allows gas to flow to the pilot burner but not to the main burner. Press and hold the ignition button (or the knob itself if there is no separate button) while you light the pilot. You should hear a clicking sound if the igniter is working; this is normal.

If there is no clicking and no electronic igniter, you will use a match or lighter instead. Either way, hold the flame to the pilot opening—the small hole where the pilot burner sits—and keep it there for 30 to 60 seconds. The pilot flame should catch within 10 to 15 seconds; if it doesn't, wait a few more seconds before trying again.

Keep holding the ignition button down for another 20 to 30 seconds after the pilot lights. This gives the thermocouple time to heat up and signal the gas valve to stay open. If you release too early, the pilot will go out when ready.

Releasing the Button and Switching to "On"

After 30 to 60 seconds of holding the button, slowly release it while watching the pilot flame. If the flame stays lit and burns steady blue, you've succeeded. Now turn the control knob from "Pilot" to "On." The main burner should ignite within a few seconds (on a furnace) or the unit should begin heating normally (on a water heater).

If the pilot goes out the moment you release the button, wait a minute and try again. Sometimes the thermocouple needs a longer warm-up. If it goes out a second time, the thermocouple is faulty and will not hold the gas valve open—this requires a technician to replace.

What to Do If the Pilot Won't Stay Lit

A pilot that lights but won't stay lit almost always means the thermocouple is worn out or positioned incorrectly. A thermocouple is a thin metal rod that sits in the pilot flame; when it gets hot, it generates a tiny electrical signal that tells the gas valve to stay open. If it's not touching the flame or if it's damaged, the valve closes when ready when you release the button.

If the pilot lights and stays lit for a few minutes before going out, the problem may be a draft blowing the flame out, a clogged pilot opening, or a failing thermocouple. A technician can diagnose which one by checking the thermocouple voltage and inspecting the pilot burner for debris. Do not attempt to clean the pilot opening yourself—the parts are delicate and easily damaged.

If the pilot won't light at all after three attempts, stop trying. The problem is likely a gas supply issue, a faulty igniter, or a blocked pilot line. Call a technician rather than continuing to attempt ignition.

Common Mistakes That Prevent Relighting

The most common mistake is releasing the ignition button too soon. Many people hold it for only 10 to 15 seconds, which is not long enough for the thermocouple to heat up. Hold it for the full 30 to 60 seconds even if the pilot lights right away.

Another mistake is not holding the flame directly in the pilot opening. If you hold the match or lighter too far away or at an angle, the pilot won't catch. The flame needs to touch the pilot burner itself. A third mistake is turning the knob to "On" before the pilot is burning steadily—if you do this and the pilot is weak, it may go out when the main burner tries to ignite.

Finally, many people assume a yellow or flickering pilot flame means the pilot is working fine. A healthy pilot should burn steady blue. A yellow flame or one that flickers means the burner is dirty or the air shutter needs adjustment—this is a job for a technician, not something to ignore.

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 early, the pilot will go out the moment you let go of the button.

What if I smell gas but don't see a flame?

Stop when ready and do not attempt to relight. Turn off the gas at the control knob, open windows and doors to ventilate, and call your service provider or a technician. Gas may be leaking into the chamber, and attempting to ignite it could be dangerous.

Can I relight the pilot if the power is out?

Yes, if your unit has a manual ignition (match or lighter). If it has an electronic igniter button, it won't work without power. In a power outage, use a long match or lighter to light the pilot manually by holding the flame to the pilot opening while the knob is on "Pilot."

Why does my pilot light keep going out after I turn it to "On"?

This usually means the thermocouple is faulty or not positioned correctly in the pilot flame. It can also happen if a draft is blowing the pilot out or if the pilot opening is clogged with debris. A technician can inspect and repair the thermocouple or clean the burner.

Is it safe to relight the pilot myself, or should I call a technician?

Relighting a pilot is safe if you follow the steps on your unit's label and smell no gas. If the pilot won't stay lit after two attempts, if you smell gas, or if you're unsure about any step, call a technician instead of continuing to try.