The basic steps to relight a pilot light

To relight your boiler pilot light, first locate the pilot light assembly—usually a small burner near the main burner inside the boiler. Turn the gas control knob to the "Off" position and wait five minutes to let any gas clear. Then turn the knob to "Pilot" and hold it down while you ignite the pilot with a long lighter or match held near the pilot opening. Keep the knob pressed for 30 to 60 seconds after the flame appears, then release it slowly. If the flame stays lit, turn the knob to "On" to restore normal operation.

The exact location of your pilot light and the labeling on your gas control knob vary by boiler model, so check your owner's manual first—it will show you the exact sequence for your unit. If you cannot find the manual, search online for your boiler's brand and model number, which is usually on a label inside the boiler door or on the side of the unit.

Key Takeaways

  • Turn the gas control knob to "Off" and wait five minutes before attempting to relight the pilot.
  • Hold the knob on "Pilot" while igniting the flame with a long lighter, then keep it pressed for 30 to 60 seconds after ignition.
  • Your boiler's manual shows the exact steps and knob positions for your specific model, so consult it before you start.
  • If the pilot light will not stay lit after three attempts, or if you smell gas, stop and call a heating technician.

Safety checks before you begin

Before you touch anything, check for gas smell. If you detect gas, do not attempt to light the pilot. Leave the building, call your gas company's emergency line from outside, and wait for them to inspect the system. A gas smell near the boiler usually means a leak, and lighting a flame could be dangerous.

Make sure the area around the boiler is clear of clutter and that you have good light. You will need to see the pilot opening clearly and hold a lighter or match steady near it. If your boiler is in a dark corner, bring a flashlight or work lamp so you can see what you are doing.

Finding the pilot light on your boiler

The pilot light assembly is typically a small metal tube or opening located near the main burner inside the boiler's combustion chamber. On most residential boilers, you will find it by opening the boiler door and looking at the bottom or side of the interior. The gas control knob is usually mounted on the outside of the boiler, near the door, and is labeled with settings like "Off," "Pilot," and "On."

Some boilers have the pilot assembly tucked behind a removable panel or access cover. If you cannot see it when ready, check whether any covers need to be removed—your manual will show you. Do not force anything open; if a panel is stuck, stop and call a technician rather than risk damaging the boiler.

What to do if the pilot light will not stay lit

If the pilot flame goes out as soon as you release the gas control knob, the thermocouple (a safety sensor that detects the pilot flame) may be dirty or faulty. Try relighting the pilot two more times, holding the knob down for the full 60 seconds each time. If it still will not stay lit after three attempts, stop trying.

A pilot that repeatedly goes out usually needs a professional repair. The thermocouple may need cleaning, the pilot opening may be clogged with debris, or the thermocouple itself may have failed. Calling a heating technician at this point is the right move—they can diagnose the problem and fix it safely without risking damage to the boiler or your safety.

When to call a heating technician instead

Do not attempt to relight the pilot if you smell gas, if the boiler is making unusual noises, or if you see visible damage to the boiler or gas lines. Also stop if you are uncomfortable working near the boiler or if you have never done this before and feel uncertain about the steps. A technician can handle the job quickly and will spot any problems you might miss.

If the pilot light goes out frequently—more than once a month—that is also a sign to call a professional. Frequent outages point to a worn thermocouple, a draft problem, or a gas pressure issue that needs diagnosis and repair. Trying to relight it repeatedly will not fix the underlying cause and may waste your time.

Tools and materials you will need

You need a long lighter (the kind used for candles or grills) or a long wooden match. A regular lighter or short match will not reach the pilot opening safely. A flashlight or work lamp is helpful if the boiler is in a dim space. That is all—you do not need any special tools or materials.

Keep a notepad nearby so you can write down the exact steps from your boiler's manual before you start. This way you can refer to it without having to hold the manual while you are working. If your manual is not available, take a photo of the gas control knob and its settings with your phone so you can see the labels clearly while you work.

Frequently Asked Questions

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

Hold it down for 30 to 60 seconds after the flame appears. This gives the thermocouple time to heat up and signal the boiler that the pilot is burning. If you release it too quickly, the flame will go out. Your manual may specify an exact time for your model, so check that first.

What does it mean if I smell gas but do not see a flame?

Stop when ready and do not try again. Gas smell without a flame means gas is being released but not igniting, which is a safety hazard. Leave the area, go outside, and call your gas company's emergency line. They will send someone to check for leaks and make sure the system is safe.

Can I relight the pilot if the boiler is still warm?

Yes, but wait at least five minutes after turning the knob to "Off" before you try to relight it. This allows any gas in the chamber to clear and cools the area enough that you can work safely. If the boiler is very hot, wait longer—there is no harm in waiting 10 or 15 minutes.

Should the pilot flame be blue or yellow?

A healthy pilot flame is mostly blue with a small yellow tip. If the flame is mostly yellow or orange, the pilot opening may be clogged with debris or the gas mixture may be off. This is not an emergency, but it is worth having a technician check during your next service visit.

What if I cannot find the gas control knob?

Check your boiler's manual or search online for your model number. The knob should be on the outside of the boiler, usually near the door or on the front panel. If you still cannot locate it, or if the knob is broken or stuck, call a technician—do not force anything or try to work around a missing control.