The basic steps to relight a pilot light
A pilot light is a small, continuous flame that ignites the main burner when you turn on a gas appliance. If it goes out, you can relight it yourself in most cases—it takes about five minutes and requires no tools. The exact steps depend on whether your appliance has an igniter button, a piezo spark, or matches, but the principle is the same: you introduce a flame to the pilot opening while gas flows to it.
Before you start, locate the pilot light assembly on your appliance. On a water heater, it is usually at the bottom of the tank behind a small access panel. On a furnace, look inside the combustion chamber near the burner. On a stove, the pilot sits beneath the cooktop or inside the oven. If you cannot find it, check the appliance manual or look for a small metal tube with a tiny opening.
Key Takeaways
- Turn the gas control knob to the "Off" position, wait five minutes for gas to clear, then turn it to "Pilot" before attempting to relight.
- Most modern appliances have an igniter button you hold down while holding a flame to the pilot opening; older models require a lit match or lighter instead.
- If the pilot will not stay lit after three or four attempts, the thermocouple (a safety sensor) may be dirty or failing and needs cleaning or replacement.
- Never force the gas control knob or explore excessive pressure—if it feels stuck, stop and call a technician rather than risk damage.
Turning off the gas and waiting for safety
Start by locating the gas control knob on your appliance. It is usually a dial or lever near the pilot light assembly, often labeled with "Off," "Pilot," and "On" positions. Turn it fully to "Off" and wait at least five minutes. This pause allows any residual gas in the line to dissipate, which prevents a dangerous buildup when you relight the pilot.
During this waiting period, open a window or door near the appliance to may support good ventilation. If you smell gas strongly or persistently, do not attempt to relight the pilot—turn off the gas at the meter and call your gas company or a technician. A strong smell suggests a leak, not just a pilot that went out.
Moving the control knob to "Pilot" and preparing to ignite
After five minutes, turn the gas control knob to the "Pilot" position. This setting allows gas to flow to the pilot opening without igniting the main burner. You should hear a faint hissing sound, which means gas is reaching the pilot. If you hear nothing, the gas supply to the appliance may be shut off at the meter or the line may be blocked—check the main gas valve and any isolation valves near the appliance.
Now prepare your ignition source. If your appliance has an igniter button (common on water heaters and furnaces made after 1990), you will use that. If it does not, you will need a long lighter or long fireplace matches. A regular match will work, but your fingers will get close to the flame, so a long lighter is safer. Have your ignition source ready before you proceed to the next step.
Using an igniter button to relight the pilot
If your appliance has an igniter button, hold it down continuously while you watch the pilot opening. You should see a spark or hear a clicking sound. Keep the button pressed for about 10 to 15 seconds while watching for a small blue flame to appear at the pilot opening. The moment you see the flame, release the button.
If no flame appears after 15 seconds, release the button, wait 30 seconds, and try again. Repeat this up to three or four times. If the pilot still will not light, the igniter may be faulty, the gas line may be blocked, or the thermocouple may need cleaning. Stop trying and move to the troubleshooting section below.
Using a lighter or match to relight the pilot
If your appliance does not have an igniter button, you will light the pilot manually. Hold the gas control knob in the "Pilot" position with one hand. With your other hand, hold a lit long lighter or long match near the pilot opening—usually a small hole or tube about the size of a pencil. The flame should be close enough to enter the opening, but not so close that you burn your hand.
Hold the flame there for about 10 seconds while keeping the gas knob pressed in the "Pilot" position. You should see a small blue flame ignite at the pilot opening. Once it does, keep the knob pressed for another 30 seconds to allow the thermocouple (a safety sensor) to heat up and signal that the pilot is lit. Then slowly release the knob. If the pilot flame goes out when ready, the thermocouple is likely dirty and needs cleaning.
Turning the knob to "On" and checking the main burner
Once the pilot light is burning steadily with a blue flame about half an inch tall, turn the gas control knob from "Pilot" to "On." On a water heater, this usually means turning it to the temperature setting you want. On a furnace, it means turning it to "On" or the heating mode. On a stove, it means the pilot is now ready to ignite the main burners when you turn a burner knob.
Wait a minute and observe the pilot flame. It should remain steady and blue. If it flickers or goes out, turn the knob back to "Off," wait five minutes, and try again. If it stays lit, test the main burner by turning on one burner (on a stove) or setting the thermostat (on a furnace or water heater). The main burner should ignite from the pilot flame. If it does not, the pilot may be positioned incorrectly or the ignition system may need service.
Cleaning the thermocouple if the pilot won't stay lit
The thermocouple is a thin metal rod that sits in the pilot flame and detects heat. When it gets dirty or corroded, it stops sending the signal that tells the gas valve to stay open, and the pilot goes out. If your pilot lights but will not stay lit after you release the knob, the thermocouple is likely the problem.
Turn the gas knob to "Off" and let the pilot cool for a minute. Locate the thermocouple—it is a thin rod, usually copper or steel, that sits in or very near the pilot flame. Gently rub it with fine steel wool or a soft cloth to remove any soot or corrosion. Do not bend it or explore force. Then try relighting the pilot using the steps above. If it still will not stay lit after cleaning, the thermocouple has likely failed and needs replacement by a technician.
When to stop and call a technician
If you have tried relighting the pilot three or four times and it will not stay lit, or if you smell gas but cannot find a leak, stop and call a technician. Do not keep trying—repeated attempts can allow gas to build up in the combustion chamber, which is a safety hazard. The same applies if the gas control knob feels stuck or damaged, or if you cannot locate the pilot light on your appliance.
A technician can diagnose whether the thermocouple has failed, the gas line is blocked, the igniter is broken, or another component needs repair. Most pilot light repairs are straightforward and inexpensive, but they require tools and knowledge that go beyond relighting. It is better to call early than to risk a gas leak or appliance damage.
Frequently Asked Questions
How long should I wait after turning the knob to "Off" before trying to relight?
Wait at least five minutes. This allows any gas in the line to clear and prevents a dangerous accumulation when you relight. If you smell gas strongly, wait longer and open windows for ventilation.
What does a healthy pilot flame look like?
A healthy pilot flame is blue, steady, and about half an inch tall. If it is yellow or orange, the burner may need cleaning. If it flickers or dances, the pilot tube may be partially blocked or the thermocouple may be loose.
Can I relight the pilot if I smell gas?
If you smell a faint gas odor only near the appliance, it is usually safe to proceed. If the smell is strong or comes from elsewhere in your home, do not relight the pilot. Turn off the gas at the meter and call your gas company—this suggests a leak, not a dead pilot.
What if the igniter button does not spark?
If you hear no clicking and see no spark, the igniter battery may be dead or the igniter may be faulty. Try using a lighter or match instead. If that works, the igniter needs replacement. If neither works, the gas line may be blocked or the thermocouple may have failed.
How often do pilot lights go out?
A healthy pilot light should stay lit indefinitely. If yours goes out regularly, the thermocouple is likely dirty or failing, the pilot tube may be clogged, or there may be a draft blowing out the flame. A technician can identify the cause and fix it.