Lighting the pilot light yourself

You can turn on your boiler's pilot light in about five minutes if you follow the right sequence. The process is the same on most modern boilers: you'll find the control knob near the burner chamber, turn it to the "Pilot" position, hold down the ignition button while holding a lit match or lighter to the pilot opening, and wait for the flame to catch. Once it stays lit for 30 seconds, you turn the knob back to "On" and the main burner should ignite within a minute.

The most common reason pilots go out is a draft—wind through a window, a door opening, or air from a nearby exhaust fan can blow out the small flame. If your pilot keeps going out after you light it, the problem is usually draft, not the boiler itself. A blocked pilot opening (from dust or debris) is the second most common cause, and you can clean it with a straightened paperclip or a thin needle.

Key Takeaways

  • Turn the control knob to "Pilot," press the ignition button, and hold a lit match to the pilot opening until the flame catches and stays lit for 30 seconds.
  • If the pilot won't stay lit, check for drafts near windows, doors, or exhaust fans that might be blowing it out.
  • A blocked pilot opening can prevent ignition—clean it gently with a straightened paperclip if you see debris.
  • If the pilot lights but the main burner doesn't ignite within a minute, or if it won't light at all after three attempts, call a technician rather than trying again repeatedly.

Locating the control knob and pilot opening

Open the boiler's access panel or door—usually a metal cover held by one or two screws or a latch. Inside, you'll see the burner chamber, a metal box where the flame burns. On the side or front of this chamber, you'll find a brass or steel control knob labeled with positions like "Pilot," "On," and sometimes "Off." The pilot opening is a small hole or tube near the knob, usually about the size of a pencil tip.

If you can't find the control knob, check the manufacturer's manual for your boiler model—the location varies slightly between brands. Most manuals are available online by searching "[your boiler brand] [model number] manual." Write down the model number from the label on the boiler before you search; it's usually on a sticker near the top or side of the unit.

The step-by-step lighting process

Turn the control knob all the way to the "Pilot" position. You should hear a faint hissing sound as gas flows to the pilot. Hold the knob in this position—some boilers require you to press it down slightly while you light the pilot, so check your manual if the knob has a push-down feature.

While holding the knob in the "Pilot" position, use a long lighter or a lit match to reach the pilot opening. You want the flame to be right at the opening, not inches away. Hold it there for 10 to 15 seconds. You should see a small blue flame appear at the pilot opening. Once it's lit, keep holding the knob down for another 15 to 30 seconds—this heats up a safety sensor called a thermocouple, which tells the boiler the pilot is burning and it's safe to deliver gas to the main burner.

Release the knob and turn it to the "On" position. Within 30 seconds to a minute, you should hear a click and the main burner should ignite with a larger flame. If nothing happens after a minute, turn the knob back to "Off," wait five minutes for any gas to clear, and try again. Do not attempt to light it more than three times in a row—if it won't light after three tries, stop and call a technician.

Why the pilot won't stay lit

The most common culprit is air movement. A boiler room door left open, a nearby exhaust fan running, or even wind coming through a crack in a window can blow out a pilot flame. The flame is small and delicate, and even gentle air currents can extinguish it. If your pilot keeps going out shortly after you light it, close all doors and windows in the boiler room and try again. If it stays lit this time, you've found your problem—improve ventilation or block the draft.

A dirty or blocked pilot opening is the second most common cause. Dust, rust, or debris can clog the tiny hole where gas flows to the pilot. If you see visible dirt or buildup around the opening, turn the knob to "Off," wait a few minutes, and then use a straightened paperclip or a thin sewing needle to gently clear the opening. Do not use anything thicker or force it—you can damage the opening. Blow away any debris with your mouth or a small brush.

A faulty thermocouple—the sensor that detects the pilot flame—can also cause the pilot to go out. If you've ruled out draft and the opening is clean, but the pilot still won't stay lit, the thermocouple likely needs replacement. This is a job for a technician, as it involves disconnecting and reconnecting gas lines.

When to call a professional instead

If you smell gas at any point during this process, stop when ready, turn the control knob to "Off," open windows and doors to ventilate the room, and leave the house. Call your gas company's emergency line from outside—do not use your phone indoors. A gas leak is a safety hazard and requires professional attention.

If the pilot lights but the main burner doesn't ignite within a minute, turn the knob to "Off" and wait five minutes before trying again. If this happens more than once, or if the pilot won't light at all after three careful attempts, call a heating technician. Repeated failed ignition attempts can waste gas and create a safety risk. A technician can diagnose whether the problem is a faulty ignition switch, a gas valve issue, or something else that requires parts replacement.

If your boiler is more than 15 years old and the pilot keeps going out even after you've cleaned the opening and ruled out drafts, the thermocouple is probably wearing out. Replacement is inexpensive and straightforward for a technician, but not a DIY job.

Preventing the pilot from going out

Keep the boiler room door closed during windy weather and when other appliances that exhaust air (like a clothes dryer or bathroom fan) are running. These appliances can create negative pressure in the room, pulling air down the boiler's vent and blowing out the pilot. If you have a high-efficiency boiler with a sealed combustion chamber, this is less of an issue, but older boilers are vulnerable.

Check the pilot opening once a year for dust or debris, especially if your boiler room is dusty or if you've had construction work nearby. A quick visual inspection takes 30 seconds and can prevent a no-heat emergency in winter. If you see buildup, clean it as described above.

If your boiler is in a damp basement, consider running a dehumidifier during humid months. Moisture can corrode the thermocouple and other components, shortening their lifespan. Keeping humidity below 50 percent helps.

Frequently Asked Questions

Can I light the pilot with a regular lighter instead of a match?

Yes. A long lighter (the kind used for candles or grills) works better than a short one because it keeps your hand farther from the burner chamber. Matches work fine too, but you need to light one quickly and get it to the pilot opening before it burns down. A long lighter gives you more time and control.

What if I smell gas but the pilot is lit?

Turn the control knob to "Off" when ready. A gas smell with a lit pilot usually means gas is leaking somewhere else in the system—not from the pilot itself. Open windows and doors, leave the house, and call your gas company's emergency line from outside. Do not use your phone indoors or turn electrical switches on or off.

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

Hold it for 15 to 30 seconds after the flame appears. This gives the thermocouple time to heat up and signal the boiler that the pilot is burning safely. If you release it too soon, the pilot may go out because the thermocouple hasn't warmed up yet.

Is it normal for the pilot to go out once or twice a year?

Once a year is not unusual, especially if you live in a windy area or if your boiler room has air movement from other appliances. More than once or twice a year suggests a draft problem, a dirty pilot opening, or a failing thermocouple. If it's happening regularly, have a technician inspect it.

What's the difference between a pilot light and the main burner flame?

The pilot is a small, steady flame that burns continuously (or on demand, depending on your boiler type). The main burner is a larger flame that heats water for your home. The pilot's job is to ignite the main burner when heat is needed. If the pilot goes out, the main burner can't light, so you lose heat.