The basic steps to relight a pilot light

To relight a pilot light on a gas heater, you need to locate the pilot light assembly (usually a small tube near the burner), turn the gas 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 gas control knob back to "On" or "Heat."

The exact location and appearance of your pilot light varies by heater model. Check your heater's manual or look for a small metal tube with a tiny opening where the flame should appear. Some heaters have an electronic ignition button; others require you to manually light the pilot with a match or lighter.

If the pilot light will not stay lit after you release the button, or if you smell gas, stop and do not attempt to relight it. Gas smell means a leak or a problem with the gas valve, both of which need professional repair.

Key Takeaways

  • Turn the gas control knob to "Pilot" before attempting to light the pilot, so gas flows only to the pilot opening and not the main burner.
  • Hold the ignition button down for 30 to 60 seconds after the flame appears, because the thermocouple needs time to heat up and signal the gas valve to stay open.
  • If you smell gas at any point, stop when ready, do not light anything, and call your gas company or a licensed technician.
  • A pilot light that goes out repeatedly usually means a faulty thermocouple, a draft problem, or a clogged pilot opening — all of which require professional service.

What you need before you start

Gather a long lighter or long matches before you approach the heater. A standard match or lighter may not reach the pilot opening safely, and your fingers could get too close to the flame or the hot heater surface. A long-reach lighter designed for candles or grills works well.

Locate your heater's manual or look for a label on the heater itself that shows where the gas control knob is and what each setting means. The knob usually has three positions: "Off," "Pilot," and "On" or "Heat." If you cannot find the manual, the manufacturer's website often has a PDF version you can read by model number.

Make sure the area around the heater is clear of clutter and that you have good lighting so you can see the pilot opening. If the heater is in a dark corner, use a flashlight or phone light to see what you are doing.

Locating the pilot light assembly on your heater

The pilot light assembly is usually mounted near the main burner, often on the side or bottom of the heater's combustion chamber. It looks like a small metal tube, usually brass or steel, with a tiny opening at the end. Some heaters have a removable access panel that you must open first to see the pilot assembly.

If your heater has a glass or metal viewing window, you may be able to see the pilot opening through it. The pilot flame, when lit, is a small blue flame about the size of a match head. If you cannot locate the pilot assembly after checking the manual, do not guess — call a technician rather than risk damaging the heater or creating a safety hazard.

The step-by-step lighting process

First, turn the gas control knob to the "Pilot" position. This setting allows gas to flow only to the pilot opening, not to the main burner. Wait a few seconds for gas to reach the pilot assembly.

Second, hold a lit match or lighter near the pilot opening. The flame should ignite when ready or within a few seconds. If nothing happens after 10 seconds, remove the lighter, wait 30 seconds, and try again. Repeated failed attempts mean gas is not reaching the pilot, which requires professional inspection.

Third, once the pilot flame appears, keep holding the ignition button (if your heater has one) or keep the lighter near the flame for 30 to 60 seconds. This time allows the thermocouple — a heat-sensing device near the pilot — to warm up. The thermocouple tells the gas valve to stay open and keep gas flowing to the pilot.

Fourth, slowly release the button or remove the lighter. If the pilot flame stays lit, turn the gas control knob to "On" or "Heat" to restore normal operation. If the flame goes out as soon as you release the button, the thermocouple may be faulty and the heater will need service.

Why your pilot light keeps going out

A pilot light that relights easily but then goes out within minutes usually has one of three problems: a weak or failing thermocouple, a draft blowing out the flame, or a clogged pilot opening.

A thermocouple is a small metal rod that sits in the pilot flame and generates a tiny electrical signal when heated. If this signal weakens, the gas valve closes and the pilot goes out. Thermocouples wear out over time and cannot be repaired — they must be replaced by a technician.

Drafts from open windows, doors, or vents can blow out a pilot flame, especially in older heaters with weaker pilots. If you notice the pilot goes out only when a window is open or when the furnace fan runs, draft is likely the cause. Closing the draft source usually solves the problem.

A clogged pilot opening happens when dust or debris blocks the tiny hole where gas flows. Cleaning the opening requires removing the pilot assembly, which is a job for a technician unless your manual explicitly allows it.

When to call a professional instead

Do not attempt to relight the pilot if you smell gas anywhere near the heater. Gas smell indicates a leak in the gas line, the control valve, or the pilot assembly itself. Turn off the heater, leave the area, and call your gas company's emergency line or a licensed HVAC technician.

If the pilot light will not stay lit even after you hold the button for the full 60 seconds, or if it goes out repeatedly within hours, the thermocouple or gas valve likely needs replacement. These parts require special tools and knowledge to replace safely, and attempting a DIY repair can damage the heater or create a safety hazard.

If you cannot locate the pilot assembly, cannot see the pilot opening clearly, or are uncomfortable working near the heater, call a technician. A service call costs less than the cost of a damaged heater or a gas leak.

Frequently Asked Questions

How long should I hold the ignition button after the pilot lights?

Hold the button for 30 to 60 seconds after the 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. If you hold it longer, that is fine — it does not hurt anything.

What if the pilot light ignites but goes out when I turn the knob to "On"?

This usually means the thermocouple is not generating enough signal to keep the main gas valve open. The thermocouple may be dirty, misaligned, or failing. A technician can clean or replace it. Do not keep relighting the pilot if this happens repeatedly.

Can I use any kind of lighter to light the pilot?

A long-reach lighter or long matches work best because they keep your hand away from the flame and the hot heater. Standard lighters and short matches can work but are harder to control and put your fingers closer to heat and flame. Avoid using a stove burner or any method that requires you to reach into the heater.

Is it normal for the pilot light to go out during a power outage?

No. A pilot light burns continuously on gas alone and does not depend on electricity. If the pilot goes out during a power outage, it was probably blown out by air movement or went out for another reason unrelated to the outage. Relight it once power is restored.

How often do pilot lights need to be relit?

A healthy pilot light should stay lit indefinitely. If you are relighting it more than once or twice a year, something is wrong — usually a thermocouple, a draft problem, or a clogged opening. Have a technician inspect the heater to find the cause.