Restart your pilot light by turning the gas valve to "Off," waiting five minutes, then switching it to "Pilot" while holding the ignition button
Most pilot lights go out because of a draft, a bent thermocouple, or sediment blocking the gas port. Before you call a technician, you can restart it yourself in about ten minutes. The process is the same whether your pilot light is on a water heater, furnace, or gas fireplace: turn off the gas, wait, then reignite.
If the pilot light won't stay lit after you restart it, or if it goes out repeatedly, the thermocouple or gas valve usually needs replacement. That is when you should call a professional. But a one-time restart is safe and straightforward.
Key Takeaways
- Turn the gas control valve to "Off" and wait five minutes to clear any gas from the line before attempting to restart.
- Switch the valve to "Pilot," press and hold the ignition button, and look for a small blue flame at the pilot burner.
- Once the pilot light is lit, hold the button for 30 to 60 seconds so the thermocouple heats up and keeps the gas flowing.
- If the pilot light goes out within hours or days, the thermocouple is likely worn and needs professional replacement.
- Never force the ignition button or hold it for more than a few minutes — if it does not light, stop and call a technician.
Locate the gas control valve and pilot assembly
On a water heater, the gas control valve is usually a knob or dial on the side of the tank near the bottom. On a furnace, it is mounted on the burner box inside the unit. On a fireplace, it is often behind a removable panel or inside the firebox itself. The valve will have three positions marked: "Off," "Pilot," and "On" (or "Heat").
Next to the valve, you will see a small metal tube running to the pilot burner — this is the gas line. At the end of that tube is a tiny opening where the pilot flame sits. You may also see a button labeled "Ignition" or "Reset" near the valve. This button triggers the spark that lights the pilot.
Turn off the gas and wait
Turn the gas control valve all the way to "Off." Do not force it — it should turn smoothly. Once it is off, wait five minutes. This clears any gas that is still in the line and makes the restart safer.
While you wait, look for the pilot light opening. It is a small hole, usually about the size of a match head, at the end of the gas tube. If you see soot or debris around it, you can gently wipe the area with a dry cloth, but do not poke into the opening itself.
Switch to Pilot and press the ignition button
Turn the gas valve to "Pilot." Now locate the ignition button — it is usually red or black and sits next to the valve. Press and hold it down. You should hear a clicking sound as the spark igniter fires. Keep holding the button while you look at the pilot burner opening.
Within a few seconds, you should see a small blue flame appear at the pilot opening. If you do not see it after five to ten seconds of holding the button, release it, wait ten seconds, and try again. Do not hold the button for more than a minute at a time — if the pilot does not light after three attempts, stop and call a technician.
Hold the button until the thermocouple heats up
Once the pilot flame appears, keep holding the ignition button for 30 to 60 seconds. This gives the thermocouple — a small metal rod in the pilot flame — time to heat up. The thermocouple senses the heat and tells the gas valve to stay open. If you release the button too soon, the gas will shut off and the flame will go out.
Watch the flame while you hold the button. It should be steady and blue. If it flickers or looks orange or yellow, the pilot may not be getting enough gas, but keep holding the button anyway. After 60 seconds, slowly release the button and watch the flame. If it stays lit, the thermocouple is working.
Turn the valve to "On" and test the system
Once the pilot light is burning steadily, turn the gas control valve from "Pilot" to "On" (or "Heat" on a furnace). The main burner should ignite within a few seconds. You will hear a whoosh as the larger flame comes to life. If the main burner does not light, turn the valve back to "Off" and try the pilot restart again.
Let the system run for a few minutes to make sure everything is stable. On a water heater, the burner should stay lit and the tank should begin to warm. On a furnace, the burner should stay on if the thermostat is calling for heat. On a fireplace, the flame should remain steady.
What to do if the pilot light will not stay lit
If the pilot light goes out within a few hours or days of restarting it, the thermocouple is almost certainly worn out. A thermocouple typically lasts 4 to 7 years. When it fails, it no longer senses the pilot flame, so the gas valve closes and the flame dies. Replacement requires removing the old thermocouple and screwing in a new one — a job that takes a technician 15 to 30 minutes.
A bent or misaligned thermocouple can also cause the pilot to go out. If you can see the thermocouple rod in the pilot flame, it should be centered in the flame, not off to the side. If it looks bent, do not try to straighten it yourself — call a technician. A damaged thermocouple is a safety issue and should be replaced, not repaired.
When to call a professional
Call a technician if the pilot light will not light after three attempts, if it goes out repeatedly within hours, if you smell gas, or if the flame is orange or yellow instead of blue. A yellow or orange flame means incomplete combustion, which can produce carbon monoxide — a serious safety hazard.
You should also call if the ignition button does not click or if you cannot locate the pilot assembly. Some older units or certain fireplace models have different layouts, and forcing the wrong component can damage the system. A technician can diagnose the problem and replace the thermocouple, gas valve, or igniter as needed.
Frequently Asked Questions
How long should I hold the ignition button?
Hold it for 30 to 60 seconds after the pilot flame appears. This gives the thermocouple time to heat up and signal the gas valve to stay open. If you release too soon, the flame will go out. If you hold it longer than a minute, you are not gaining anything — release it and watch the flame.
What does it mean if the pilot flame is orange instead of blue?
An orange or yellow flame usually means the pilot is not getting enough air or the burner is dirty. It can also indicate incomplete combustion, which produces carbon monoxide. Turn off the gas and call a technician. Do not use the appliance until it is checked.
Can I restart the pilot light if I smell gas?
No. If you smell gas, turn the gas valve to "Off" when ready, open windows and doors, and leave the building. Call your gas company's emergency line from outside. Do not use any electrical switches or create sparks. A gas leak is a serious safety issue.
How often do pilot lights go out on their own?
A healthy pilot light should stay lit indefinitely. If yours goes out once a year or less, it is probably fine — a draft or a temporary issue. If it goes out every few weeks or months, the thermocouple is likely failing and should be replaced by a technician.
Do I need to bleed air from the line before restarting?
No. The five-minute wait after turning off the gas is enough. You do not need to open any valves or bleed lines yourself. If air is trapped in the line, the pilot may take a few extra seconds to light, but it will light once the gas reaches the burner.