How to Light a Pilot Light
A pilot light is a small, continuous flame that ignites the main burner when your appliance needs heat. If your pilot light has gone out, you can relight it yourself in most cases—it takes about five minutes and requires no tools. The process is nearly identical whether you have a water heater, furnace, or gas stove, though the exact location of controls varies by model.
Before you start, locate your appliance's instruction manual or look for a label on the unit itself. The label usually shows a diagram of the control knob positions and the lighting steps. If you cannot find either, the steps below cover the standard method used by most manufacturers.
Key Takeaways
- Turn the control knob to "Off" and wait five minutes to let any gas clear before attempting to light the pilot.
- Switch the knob to "Pilot," hold down the ignition button, and hold a lit match or lighter to the pilot opening until the flame catches.
- Keep the ignition button pressed for 30 to 60 seconds after the flame appears so the thermocouple can heat up and sense the flame.
- Once the pilot stays lit on its own, turn the knob to "On" to restore normal operation.
- If the pilot will not stay lit after three attempts, the thermocouple may need replacement and a technician should inspect the unit.
Locate the Pilot Light Opening and Control Knob
Open the access panel or door to your appliance. On a water heater, this is usually a small metal door at the base. On a furnace, you may need to remove a cover panel. Inside, you will see a small metal tube (the pilot opening) and a control knob labeled with settings like "Off," "Pilot," and "On."
The pilot opening is typically a small brass or steel nozzle. It may have a thin tube running to it from the control valve. Look for any existing flame—if the pilot is already lit, you do not need to relight it. If there is no flame, proceed to the next step.
Turn Off the Gas and Wait
Turn the control knob all the way to "Off." This stops gas flow to both the pilot and the main burner. Wait at least five minutes. This pause allows any residual gas inside the appliance to disperse, which reduces the risk of a small explosion when you introduce a flame.
Do not skip this step, even if you are in a hurry. Five minutes is a standard safety measure used by all appliance manufacturers.
Switch to Pilot Mode and Prepare to Ignite
Turn the control knob to the "Pilot" position. You should hear a faint hissing sound—this is gas flowing to the pilot opening. Now locate the ignition button, which is usually a red or black button on the control valve itself. You will need to press and hold this button while you light the pilot.
Have your ignition source ready before you press the button. A long-reach lighter or a long match works best because it keeps your hand away from the pilot opening. A standard match is harder to control but will work if you are careful. Do not use a cigarette lighter held at an angle—the flame can be unpredictable.
Light the Pilot and Hold the Button
Press and hold the ignition button with one hand. Bring your lit match or lighter to the pilot opening with your other hand. You should see a small blue flame ignite at the opening. The moment the flame appears, keep it steady and continue holding the ignition button.
Hold the button down for 30 to 60 seconds after the flame appears. This is critical: the thermocouple (a heat-sensing device near the pilot flame) needs time to warm up and signal to the control valve that a flame is present. If you release the button too soon, the pilot will go out as soon as you remove your ignition source.
If the pilot does not light on the first try, release the button, wait 30 seconds, and try again. Repeat up to three times. If it still will not light, stop and move to the troubleshooting section below.
Turn the Knob to On and Check for Steady Flame
Once the pilot flame is steady and you have held the button for the full 30 to 60 seconds, slowly release the ignition button. The pilot should stay lit. If it goes out when ready, the thermocouple may not be working—see the troubleshooting section.
If the pilot stays lit, turn the control knob from "Pilot" to "On." You may hear a click or a soft whoosh as the main burner ignites. The main flame should be blue and steady. If it is yellow or orange, or if it flickers, turn the knob back to "Off" and wait five minutes before trying again.
Your appliance should now operate normally. The pilot will remain lit continuously, and the main burner will turn on and off as your thermostat or timer calls for heat.
What to Do If the Pilot Will Not Stay Lit
If you have tried lighting the pilot three times and it goes out each time you release the ignition button, the thermocouple is likely faulty. The thermocouple is a safety device that detects the pilot flame; if it is not working, the control valve will not stay open. A faulty thermocouple cannot be repaired at home and must be replaced by a technician.
Do not attempt to hold the ignition button down indefinitely or to bypass the safety system. These devices exist to prevent gas from flowing when there is no flame to ignite it. If the pilot will not light after three attempts, or if it lights but will not stay lit, contact a licensed HVAC technician or plumber to inspect the unit. Continuing to try may waste gas and create a safety hazard.
Common Mistakes to Avoid
Do not skip the five-minute wait after turning the knob to "Off." Residual gas can create a small pop or flash when you introduce a flame, which is startling and potentially dangerous. The wait is not optional.
Do not release the ignition button too soon. Many people light the pilot, see the flame, and when ready let go of the button. The flame will go out because the thermocouple has not warmed up yet. Hold the button for the full 30 to 60 seconds even though the flame is already visible.
Do not use a regular lighter held at an awkward angle. The flame will be hard to control and may not reach the pilot opening. A long-reach lighter or a long match gives you better aim and keeps your hand farther from the heat.
Do not assume the pilot is out just because you cannot see it from the access door. Some pilot openings are recessed or angled. Look carefully, and if you are unsure, proceed with the lighting steps—if the pilot is already lit, nothing will happen.
Frequently Asked Questions
How long should the pilot flame be?
The pilot flame should be about one-half to one inch tall and blue in color. If it is very small (less than one-quarter inch) or yellow or orange, the pilot may not be burning cleanly. A yellow flame suggests the burner opening is dirty. Turn off the appliance and contact a technician to have the pilot cleaned.
Can I light the pilot with just a match if I do not have a lighter?
Yes, but a long match is safer than a short one. Strike the match, hold it steady, and bring it to the pilot opening while you press the ignition button. A standard match will work, though your hand will be closer to the heat. Never use a wooden match that is already half-burned—it will be too short to control safely.
What does it mean if the pilot lights but goes out when I release the button?
This almost always means the thermocouple is not sensing the flame. The thermocouple needs 30 to 60 seconds of heat to set up the control valve. If you held the button long enough and the pilot still goes out, the thermocouple is likely faulty and needs replacement by a technician.
Is it normal for the pilot to make a hissing sound?
Yes. A soft hissing is the sound of gas flowing to the pilot opening. A loud hiss or a roaring sound suggests too much gas is flowing, which is not normal. Turn the knob to "Off" and contact a technician to check the gas pressure and pilot adjustment.
How often do pilot lights go out?
A pilot light should stay lit indefinitely once it is properly lit. If your pilot goes out frequently (more than once a month), the thermocouple may be wearing out, the pilot opening may be clogged with debris, or there may be a draft blowing out the flame. Have a technician inspect the unit to find the cause.