The basic steps to relight a pilot light

To relight a gas pilot light, first locate the control knob on your appliance—usually on the front of a water heater, furnace, or stove. Turn the knob to the "Off" position and wait five minutes to let any gas dissipate. Then turn the knob to "Pilot" and hold it down while you ignite the pilot opening with a long lighter or match. 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." If it goes out, wait five minutes and try again.

The exact location of the pilot opening and the shape of the control knob vary by appliance and manufacturer. Before you start, check the label on your appliance or look inside the access panel—most have a diagram showing where the pilot is and which direction to turn the knob. Some appliances have a small red button instead of a knob; press and hold that button instead of turning a knob.

Key Takeaways

  • Turn the control knob to "Off" and wait five minutes before attempting to relight the pilot.
  • Switch the knob to "Pilot," hold it down, and use a long lighter or match to ignite the pilot opening.
  • Keep the knob pressed for 30 to 60 seconds after the flame appears so the thermocouple can heat up and sense the flame.
  • If the pilot light goes out again after you release the knob, the thermocouple may be faulty and you should call a technician.

Why the pilot light goes out

A pilot light usually goes out because of a draft, a clogged pilot opening, or a failing thermocouple. A draft from an open window or door can blow out the small flame. A thermocouple is a heat-sensing device that sits near the pilot flame; if it is dirty or worn, it stops sensing the flame and shuts off the gas supply as a safety measure.

If you relight the pilot and it stays on, you are done. If it goes out within a few minutes or hours, the thermocouple is likely the problem. A thermocouple costs between $15 and $30 as a part, but replacing it requires opening the appliance and removing the old one—this is a job for a technician unless you are experienced with gas appliances.

Safety steps before you start

Never attempt to relight a pilot light if you smell gas. Leave the area, open windows and doors, and call your gas company's emergency line or 911. Do not use a lighter, match, or any ignition source if you suspect a gas leak.

Make sure the appliance has been off for at least five minutes before you try to relight the pilot. This gives any gas that may have accumulated time to clear. If you have tried to relight the pilot more than three times in a row without success, stop and call a technician—repeated attempts can allow gas to build up inside the appliance.

Finding the pilot light and control knob

On a water heater, the pilot light is usually at the bottom of the tank, visible through a small window or opening. On a furnace, it is typically inside the combustion chamber, which you access by opening a panel on the front or side of the unit. On a stove, the pilot light is usually under the cooktop or inside the oven, depending on the model.

The control knob is almost always on the outside of the appliance where you can reach it without opening anything. It will have three positions: "Off," "Pilot," and "On." Some older appliances use a red button instead. If you cannot find the control knob or the pilot opening, check the manufacturer's manual or look for a label on the appliance itself—most have a diagram printed on the back or inside the access panel.

Lighting the pilot with a long lighter or match

A long lighter (the kind used for candles or grills) is safer and easier than a match because it keeps your hand farther from the flame. Hold the lighter or match near the pilot opening while you press and hold the control knob in the "Pilot" position. The pilot should ignite within a few seconds.

Once the pilot flame appears, keep the knob pressed down for 30 to 60 seconds. This allows the thermocouple to heat up and sense the flame, which tells the appliance that the pilot is burning and it is safe to keep the gas flowing. If you release the knob too soon, the thermocouple may not have warmed up enough, and the flame will go out.

What to do if the pilot light will not stay lit

If the pilot light goes out as soon as you release the knob, wait five minutes and try again. Sometimes the thermocouple needs a second or third attempt to heat up properly. If it goes out again, the thermocouple is probably faulty and needs to be replaced.

If the pilot light stays on for a few hours or a day and then goes out, the problem is usually a draft or a dirty pilot opening. Check for open windows or doors near the appliance and close them. If that does not help, the pilot opening may be clogged with dust or debris. Cleaning it requires opening the appliance, which is best left to a technician.

When to call a professional

Call a technician if the pilot light will not stay lit after two or three attempts, if you smell gas at any point, or if the appliance is making unusual noises or smells. Do not try to force the issue—gas appliances are safety-critical, and a faulty pilot light system can be dangerous.

A technician can test the thermocouple, clean the pilot opening, check the gas line for leaks, and replace any worn parts. The cost varies by region and appliance type, but a service call usually runs between $100 and $200. If the thermocouple needs replacement, add another $50 to $100 for the part and labor.

Frequently Asked Questions

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

Hold the knob in the "Pilot" position for 30 to 60 seconds after the flame appears. This gives the thermocouple time to heat up and sense the flame. If you release it too soon, the flame may go out because the thermocouple has not warmed up enough to signal the appliance to keep the gas flowing.

What if I cannot see the pilot opening?

Check the manufacturer's manual or look for a diagram on the appliance itself. If the pilot opening is inside a closed chamber, you may need to open an access panel to see it. Some appliances have a small window you can look through. If you still cannot locate it, a technician can show you where it is and how to access it safely.

Is it safe to relight the pilot myself?

Yes, relighting a pilot light is a safe task if you follow the steps carefully and stop if you smell gas. The pilot light is designed to be relit by homeowners. However, if the pilot will not stay lit or you suspect a gas leak, call a technician instead of trying again.

Can I use a regular match instead of a long lighter?

Yes, but a long lighter is safer because it keeps your hand farther from the flame and the pilot opening. If you use a match, light it first and then hold it near the pilot opening while you press the knob. Be careful not to burn your fingers.

Why does the pilot light keep going out?

The most common cause is a faulty thermocouple, which stops sensing the flame and shuts off the gas supply. A draft from an open window or door can also blow out the pilot. If relighting it does not solve the problem, the thermocouple likely needs replacement by a technician.