The quickest way to check your pilot light
The fastest way to check your pilot light is to look at it directly. Most pilot lights sit inside the burner compartment of your furnace, water heater, or gas stove, and you can see the small blue flame if it is lit. Open the access panel or door to the appliance, look into the chamber where the burner sits, and look for a steady blue flame about the size of your pinky fingernail. If you see that flame, your pilot light is on. If you see nothing, or only darkness, the pilot light is out.
The location varies by appliance. On a gas water heater, the pilot light is usually visible through a small window or opening near the bottom of the tank. On a furnace, you may need to open the front panel to see into the combustion chamber. On a gas stove, the pilot light is often at the back of the stovetop or inside the oven. Check your appliance's manual or look for a small opening with a view into the burner area.
Key Takeaways
- A lit pilot light shows as a small, steady blue flame visible through the appliance's access opening or window.
- If you see no flame or only darkness when you look into the burner chamber, the pilot light is out.
- The location of the pilot light differs by appliance—check your manual or look for a small viewing window near the burner.
- A yellow or orange flame instead of blue means incomplete combustion and signals a need to call a technician.
- If the pilot light is out, you can attempt to relight it yourself on most appliances, but call a professional if it will not stay lit.
What a healthy pilot light looks like
A working pilot light burns with a steady, bright blue flame. The flame should be about half an inch to an inch tall and should not flicker or dance around. It should stay in one place and burn continuously without going out on its own. The blue color tells you the gas is burning cleanly and completely.
If the flame is yellow, orange, or has a yellow tip, that is a sign of incomplete combustion—usually caused by dust in the burner or a problem with the gas mixture. This is not an emergency, but you should call a technician to clean the burner or adjust the gas flow. Do not try to fix this yourself.
Why your pilot light might be out
The most common reason a pilot light goes out is a draft or air movement blowing it out. This happens more often in basements, attics, or rooms with open windows or doors near the appliance. A sudden gust when you open a door, or even steady air from a ceiling fan or return vent, can extinguish the flame.
Other reasons include a clogged pilot tube (the small opening where gas flows to the pilot), a faulty thermocouple (a safety device that shuts off gas if the pilot goes out), or low gas pressure. If your pilot light goes out once and you relight it successfully, it was probably a draft. If it goes out repeatedly, the thermocouple or gas line may need professional attention.
How to safely relight a pilot light
Before you attempt to relight a pilot light, turn off the gas supply to the appliance. Most appliances have a control knob or valve near the burner—turn it to the "Off" position. Wait at least five minutes for any gas to clear from the chamber. This step is important for your safety.
Next, locate the ignition button or spark igniter. On many appliances, this is a red or black button near the pilot opening. Press and hold this button while holding a long lighter or match near the pilot opening. You should see the blue flame ignite. Keep holding the button for 30 to 60 seconds after the flame appears—this allows the thermocouple to heat up and signal that the pilot is lit. Then release the button and turn the control knob back to "On" or "Pilot," depending on your appliance.
If the pilot light will not stay lit after you release the button, or if it goes out again within a few minutes, do not keep trying. This usually means the thermocouple is failing or there is a gas flow problem. Call a technician at this point—repeated attempts can waste gas and create a safety hazard.
When to call a professional instead
Call a technician if your pilot light will not relight after one or two attempts, if it goes out repeatedly after you relight it, or if you smell gas around the appliance. You should also call if you are uncomfortable opening the appliance or using a lighter near the burner, or if you cannot locate the pilot light or ignition button.
If your appliance is very old or you are not sure how it works, a professional visit is the safer choice. Technicians can test the thermocouple, check gas pressure, clean the burner, and make sure everything is working safely. The cost of a service call is usually between $100 and $200, depending on your area and the appliance.
Preventing pilot light problems
Keep the area around your appliance clear of clutter and drafts. Do not place fans, open windows, or return air vents directly near a furnace or water heater. If your pilot light goes out often in winter, check for drafts from doors or windows and seal them if possible.
Have your furnace or water heater serviced once a year by a technician. During a service call, they will clean the burner and pilot tube, test the thermocouple, and make sure the gas pressure is correct. This routine maintenance prevents most pilot light problems and keeps your appliance running safely and efficiently.
Frequently Asked Questions
Can I check the pilot light without opening the appliance?
On some appliances, yes—if there is a viewing window or glass panel, you can see the pilot light without opening anything. On others, you will need to open an access panel or door. Check your manual first to see if your appliance has a window. If it does not, you will need to open it safely to look inside.
What should I do if I smell gas when I check the pilot light?
Stop when ready and leave the area. Do not light a match or use any ignition source. Open windows and doors to ventilate the space, then call your gas company's emergency line or a technician. A gas smell usually means a leak, and you should not attempt to relight the pilot yourself.
Is it normal for the pilot light to go out once in a while?
Going out once or twice a year is usually not a concern—it is often caused by a draft or wind. If it goes out more than once a month, or if it goes out and will not relight, something is wrong with the thermocouple, gas line, or burner. Have a technician inspect it.
How long does it take to relight a pilot light?
The whole process usually takes five to ten minutes—waiting for gas to clear, locating the ignition button, lighting the pilot, and holding the button while the thermocouple heats up. If it takes longer than that or the pilot will not stay lit, stop and call a professional.
Can a pilot light cause a fire?
A working pilot light is safe—it is designed to burn continuously and is enclosed inside the appliance. A problem pilot light (one that will not light, or one that is yellow instead of blue) is not a fire risk, but it means the appliance is not working correctly and should be serviced.