The basic steps to light a pilot light

To light your heater's pilot light, you will need to locate the pilot burner (a small opening near the main burner), set your thermostat to the lowest setting, turn the gas control knob to "Pilot," hold down the ignition button while bringing a long lighter or match to the pilot 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 to "On" and raise your thermostat to your desired temperature.

The exact location of these controls varies by heater model. Check your owner's manual or look for a diagram printed on the heater itself — most units have a label on the access panel that shows where the pilot knob, ignition button, and pilot opening are positioned.

If you cannot find these controls or your heater does not have a manual ignition button, your unit may have an electronic igniter instead. Electronic igniters light the pilot automatically when you turn the gas knob to "Pilot" and do not require a match or lighter.

Key Takeaways

  • Set your thermostat to the lowest setting and turn the gas control knob to "Pilot" before attempting to light the pilot.
  • Hold down the ignition button while using a long lighter or match to reach the pilot opening, then keep the button pressed for 30 to 60 seconds after the flame appears.
  • Once the pilot flame holds steady on its own, turn the gas knob to "On" and adjust your thermostat to your desired temperature.
  • If your heater has an electronic igniter instead of a manual button, the pilot will light automatically when you turn the gas knob to "Pilot."
  • Refer to your owner's manual or the diagram on your heater's access panel to locate the exact controls on your specific model.

Why the pilot light goes out and when to relight it

A pilot light can go out for several reasons: a draft blowing it out, a buildup of dust or debris blocking the flame, a faulty thermocouple (the safety device that detects the pilot flame), or straightforward age and wear. If your pilot light goes out once and relights easily, it was likely a draft. If it goes out repeatedly within hours or days, the thermocouple may be failing or the pilot opening may be clogged.

A thermocouple is a small metal rod positioned in the pilot flame. When it senses heat, it signals the gas valve to stay open. If the thermocouple is worn out, the gas valve closes even when the pilot is burning, causing the flame to die. This is the most common reason for a pilot that will not stay lit.

If relighting the pilot does not solve the problem, or if the pilot flame is very small or yellow instead of blue, contact a heating technician. These signs point to a component that needs replacement rather than a straightforward relight.

Safety steps before you begin

Before lighting a pilot, make sure the area around your heater is clear of flammable materials — keep paper, cloth, and other combustibles at least three feet away. Do not attempt to light the pilot if you smell gas in the room; instead, open windows and doors to ventilate, leave the building, and call your gas company's emergency line from outside.

Wear long sleeves or use a long lighter to keep your hand away from the pilot opening and any hot surfaces. The metal around the pilot can be hot enough to burn skin, especially if the heater has been running recently. If you are uncomfortable working near the heater or unsure about your model's controls, a heating technician can light the pilot for you.

Never force any knobs or buttons. If a control feels stuck or will not turn, stop and consult your manual or call a technician. Forcing a stuck knob can damage the gas valve.

Troubleshooting a pilot that will not stay lit

If the pilot lights but goes out within seconds or minutes, the thermocouple is the most likely culprit. To test it, light the pilot and hold the ignition button down for a full 60 seconds — if the flame dies as soon as you release the button, the thermocouple is not sensing the heat properly and will need to be replaced.

A second common cause is a clogged pilot opening. Dust and debris can block the small hole where gas flows to the pilot burner. If you are comfortable doing so, you can gently clean the opening with a thin wire or needle — turn off the gas first and let the heater cool. Do not use a tool thick enough to enlarge the opening or damage the burner.

If the pilot flame is very small, yellow, or orange instead of blue, the pilot opening or gas line may be partially blocked. This also requires cleaning or professional service. A healthy pilot flame is bright blue and about half an inch tall.

When to call a heating technician instead

If the pilot will not light at all after several attempts, if you smell gas while trying to light it, or if the heater makes unusual sounds when you turn the gas knob, stop and contact a heating technician. These are signs of a gas leak, a faulty valve, or another problem that requires professional diagnosis.

You should also call a technician if the pilot lights but the main burner does not ignite after you turn the thermostat up, or if the heater turns on and off repeatedly without maintaining heat. These problems point to issues beyond the pilot light itself.

A heating technician can inspect the thermocouple, gas valve, and ignition system, clean blocked openings, and replace worn parts. The cost of a service call is usually less than the cost of a new heater, and a professional can identify problems that are not safe to troubleshoot on your own.

Frequently Asked Questions

How long should I hold the ignition button down?

Hold the button 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 the button too soon, the flame will go out.

What if I do not have a long lighter or matches?

A long lighter is safest because it keeps your hand farther from the flame and hot surfaces. If you do not have one, a long wooden match works, or you can hold a regular lighter at arm's length. Do not use rolled paper or other makeshift tools — they can catch fire.

Can I light the pilot if the heater is still warm?

Yes, but be careful. The metal around the pilot opening will be hot and can burn your skin. Wear long sleeves or use a long lighter to keep your hand away. If the heater is very hot, wait 10 to 15 minutes for it to cool slightly.

What does a blue pilot flame mean versus a yellow one?

A blue flame means the pilot is burning cleanly and getting the right mix of gas and air. A yellow or orange flame means the opening is clogged or the gas is not flowing properly. A yellow pilot will not heat the thermocouple reliably and should be cleaned or serviced.

Do I need to do anything special if my heater has not been used in months?

No, the process is the same. The pilot may take a few extra seconds to light if dust has settled in the opening, but follow the standard steps. If it does not light after three or four attempts, stop and let the gas clear for a few minutes before trying again.