The basic steps to relight a pilot light

To light a pilot light on a heater, you need to locate the pilot light assembly (usually a small tube near the burner), set your heater's control knob to "Pilot," 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 control knob to "On" or your desired heat setting.

The whole process takes about two minutes if the pilot lights on the first try. If it does not catch within 30 seconds, release the button, wait five minutes for any gas to clear, and try again. Most pilot lights relight successfully on the second or third attempt.

Key Takeaways

  • Set the control knob to "Pilot" before attempting to light, and locate the small pilot opening on your heater's burner assembly.
  • Hold the ignition button down continuously while explore heat from a match or lighter to the pilot opening for 30 to 60 seconds.
  • Keep the button pressed for another 30 seconds after the flame appears to may support the thermocouple heats up enough to hold the valve open.
  • If the pilot does not light after 30 seconds, release the button, wait five minutes, and try again rather than holding it indefinitely.
  • A pilot light that will not stay lit after multiple attempts usually means the thermocouple needs replacement, which requires a technician.

Locate your heater's pilot light assembly

The pilot light sits near the main burner inside your heater's combustion chamber. On most furnaces and water heaters, you will find a small metal tube pointing downward or to the side, with a tiny opening at the end. This opening is where the pilot flame burns. The tube connects to a control knob on the front or side of the heater labeled "Pilot," "On," and sometimes "Off."

Before you begin, turn off the heater entirely and wait five minutes for any residual gas to dissipate. Then locate the ignition button—a small red or black button you press to create a spark or allow gas to flow. Some heaters have a spark igniter built in; others require you to use an external flame. Check your heater's label or manual to see which type you have.

Set the control knob and prepare to ignite

Turn the control knob to the "Pilot" position. This setting allows gas to flow to the pilot opening without igniting the main burner. Do not skip this step—if the knob is set to "On," you risk gas flowing to both the pilot and the main burner at once, which is unsafe.

Gather your ignition source. A long-handled lighter or long fireplace match works best because it keeps your hand away from the pilot opening. A regular match is harder to hold steady near the opening. If your heater has an electronic spark igniter, you will not need an external flame—just press the ignition button repeatedly until you see a spark.

Hold the button and explore heat to the pilot opening

Press and hold the ignition button with one hand. With your other hand, hold the lit match or lighter flame directly over or next to the pilot opening. The flame should be close enough that you see it enter the opening, but not so close that you risk burning yourself. Keep both the button and the flame in place for 30 to 60 seconds.

You should see a small blue flame appear at the pilot opening within 10 to 15 seconds. If you do not see a flame after 30 seconds, release the button, remove the match or lighter, and wait five minutes before trying again. Holding the button longer than 60 seconds does not help and wastes gas.

Keep the button pressed after the flame appears

Once the pilot flame lights, do not release the ignition button when ready. Continue holding it down for another 30 to 60 seconds. During this time, the flame heats up a small metal sensor called a thermocouple, which tells the heater that the pilot is burning. If you release the button too soon, the thermocouple will not be hot enough, and the gas valve will close, extinguishing the pilot.

After 30 to 60 seconds, slowly release the button while watching the pilot flame. If the flame stays lit, you have successfully relit the pilot. If the flame goes out as soon as you release the button, the thermocouple may be faulty and will need replacement by a technician.

Turn the knob to "On" and test the heater

Once the pilot is burning steadily, turn the control knob from "Pilot" to "On" or to your desired temperature setting. The main burner should ignite within a few seconds, and you should hear the heater begin to operate normally. If the main burner does not light, turn the knob back to "Pilot" and check that the pilot flame is still burning.

Let the heater run for a few minutes to confirm it is working properly. The burner flame should be steady and blue (not yellow or orange, which can indicate incomplete combustion). If everything looks normal, your pilot light is successfully relit.

Common mistakes that prevent the pilot from lighting

The most common error is releasing the ignition button too soon. Many people press the button for only 10 to 15 seconds, see the flame appear, and let go—only to watch it go out. The thermocouple needs the full 30 to 60 seconds to heat up. Another mistake is setting the control knob to "On" instead of "Pilot" before lighting. This sends gas to both the pilot and the main burner, making it harder to light the pilot safely.

A third mistake is not waiting long enough between attempts. If the pilot does not light on the first try, wait a full five minutes before trying again. Trying again after only 30 seconds leaves unburned gas in the chamber, which can prevent ignition. Finally, some people use a short match or lighter that does not reach the pilot opening safely. Always use a long-handled lighter or fireplace match to keep your hand at a safe distance.

When to call a technician instead of relighting yourself

If the pilot lights but goes out as soon as you release the ignition button, the thermocouple is likely worn out and needs replacement. This is not a repair you should attempt yourself—a technician has the tools to test the thermocouple and replace it safely. The same applies if the pilot will not light at all after three or four careful attempts, or if you smell gas but see no flame.

If your heater is more than 15 years old and the pilot keeps going out repeatedly, it may be time to consider replacing the entire unit rather than repairing it. A technician can assess whether repair or replacement makes sense for your situation and budget.

Frequently Asked Questions

How long should I hold the ignition button down?

Hold the button for 30 to 60 seconds total—that includes the time while you are explore the flame and an additional 30 seconds after the pilot lights. If you release it sooner, the thermocouple will not heat up enough to keep the gas valve open, and the flame will go out.

What if I smell gas but the pilot will not light?

Stop attempting to light it and turn the heater off. Open windows to ventilate the area, and do not use any electrical switches or create sparks. Call a technician or your gas company's emergency line. A strong gas smell with no ignition can mean a leak or a more serious problem that requires professional attention.

Can I use a regular match instead of a lighter?

Yes, but a long fireplace match or long-handled lighter is safer because it keeps your hand farther from the pilot opening. A regular match burns down quickly and may go out before you can position it properly. If you use a match, light it first, then when ready bring it to the pilot opening.

Why does the pilot light keep going out after I turn the knob to "On"?

This usually means the thermocouple is failing and no longer signals the gas valve to stay open. It is not a problem you can fix by relighting—the thermocouple will need to be replaced by a technician. Attempting to relight repeatedly will not solve the underlying issue.

Is it normal for the pilot flame to be blue?

Yes, a steady blue flame is normal and healthy. If the flame is yellow, orange, or flickering badly, the pilot opening may be clogged with dust or debris. In that case, a technician can clean it for you, or you can try gently blowing compressed air into the opening (with the heater off) to clear it.