A pilot light should stay on in most gas appliances, but the answer depends on the type of appliance and the season
For most gas furnaces, water heaters, and stoves, the pilot light is designed to burn continuously. It sits there waiting to ignite the main burner when you need heat or flame. Turning it off and on repeatedly can wear out the ignition system faster than leaving it lit, and it defeats the purpose of having a pilot light in the first place — which is to be ready when ready when you call for it.
That said, some appliances have pilot lights you can safely turn off during seasons you don't use them. Gas fireplaces are the most common example. If you live somewhere with mild winters or you straightforward don't use your fireplace in summer, turning off the pilot light during those months saves gas and is perfectly safe. The same applies to some gas grills and outdoor heaters.
The key difference is whether the appliance needs to respond on demand. A furnace or water heater needs its pilot light ready 24/7 because you might need heat at any time. A fireplace you control manually can have its pilot light off when you're not using it.
Key Takeaways
- Furnaces, water heaters, and gas stoves should have their pilot lights on continuously, because turning them on and off wears the ignition system and defeats the when ready-ignition purpose.
- Gas fireplaces, grills, and outdoor heaters can have their pilot lights turned off during seasons you don't use them without any risk to the appliance.
- A pilot light that goes out on its own signals a problem — usually a draft, a dirty thermocouple, or a gas supply issue — and should be relit or inspected.
- Relighting a pilot light yourself is safe if you follow the appliance manual's exact steps, but if it won't stay lit after two attempts, call a technician.
Why furnaces and water heaters need the pilot light on year-round
Your furnace's pilot light is always ready to ignite the main burner the moment your thermostat calls for heat. If you turned it off in spring and back on in fall, you'd be cycling the ignition system through unnecessary stress. Modern ignition systems are built to handle this, but they wear faster with repeated on-off cycles than they do running continuously at a low flame.
Water heaters work the same way. The pilot light stays on so the appliance can heat water whenever you turn on a hot tap or run a shower. Turning it off and on seasonally doesn't save enough gas to justify the wear on the ignition system or the inconvenience of waiting for it to relight.
The gas cost of a continuously burning pilot light is small — typically a few dollars per month — compared to the cost of replacing an ignition system or dealing with a no-heat emergency because the pilot won't relight.
When you can safely turn off a pilot light
Gas fireplaces are designed for manual control. You light the pilot when you want to use the fireplace and can turn it off when you don't. Many people turn off the pilot in late spring and relight it in fall, which is perfectly safe and does save gas over several months.
Gas grills, patio heaters, and some space heaters follow the same logic. These are appliances you use on demand, not appliances that need to be ready at all times. Turning off the pilot during off-season is a reasonable choice if you want to save gas.
Always check your appliance manual before turning off a pilot light. Some fireplaces have safety interlocks or specific instructions about seasonal shutdown. Following the manual protects both the appliance and your safety.
What to do if your pilot light goes out on its own
A pilot light that extinguishes without you turning it off is not normal and usually signals one of three problems: a draft blowing out the flame, a dirty or misaligned thermocouple (the sensor that tells the gas valve the pilot is lit), or a gas supply issue.
If your pilot light goes out, the first step is to check for drafts near the appliance. Close windows and doors in the room, and look for any obvious air leaks around the furnace or water heater. If you find a draft, seal it and try relighting the pilot according to your manual.
If the pilot won't stay lit after two attempts, or if it goes out repeatedly, stop trying and call a technician. A thermocouple can be cleaned or replaced, and a gas supply problem needs professional diagnosis. Repeatedly relighting a pilot that won't hold is frustrating and wastes time.
How to relight a pilot light safely
Relighting a pilot light yourself is safe if you follow your appliance manual exactly. The basic steps are the same across most furnaces and water heaters: locate the pilot light access panel, find the ignition button or knob, and follow the manual's instructions for your specific model.
Most manuals tell you to turn the gas control knob to "Pilot," hold down the ignition button for 30 to 60 seconds while holding a lit match or lighter near the pilot opening, then release the button and turn the knob to "On." Some newer appliances have electronic ignition and don't require a match.
Never force anything. If the knob is stuck, if you smell gas, or if the pilot won't light after following the manual's steps, stop and call a technician. A gas leak or mechanical problem is not something to troubleshoot on your own.
Pilot light safety and gas consumption
A continuously burning pilot light is safe. It's a small, controlled flame designed to burn indefinitely. The gas it uses is minimal — typically equivalent to a small burner on your stove running for a few minutes each day.
The real safety concern is a pilot light that won't stay lit or a furnace that won't ignite when you need it. These are signs of a problem that needs attention, not signs that the pilot light itself is unsafe.
If you smell gas near your furnace, water heater, or any gas appliance, do not attempt to relight the pilot. Leave the area, open windows, and call your gas company or a technician when ready. A gas smell means a leak, not a straightforward pilot light issue.
Pilot lights on older versus newer appliances
Older furnaces and water heaters almost always have standing pilot lights that burn continuously. Newer models often have electronic ignition systems that light the burner only when needed, with no pilot light at all. If your appliance has no pilot light, it's using electronic ignition and you don't need to worry about this question.
If your appliance does have a pilot light, the principle remains the same: leave it on for furnaces and water heaters, and turn it off seasonally for fireplaces and grills if you choose to.
When you're shopping for a new furnace or water heater, electronic ignition is generally more efficient than a standing pilot light, though the difference is small. Either type is reliable and safe when properly maintained.
Frequently Asked Questions
Does leaving a pilot light on all the time waste a lot of gas?
No. A pilot light uses roughly the same amount of gas as a single burner on your stove running for a few minutes per day. Over a month, it typically costs a few dollars. The cost of replacing an ignition system or dealing with a no-heat emergency is far higher.
Can I turn off my furnace's pilot light in summer?
You can, but it's not recommended. Turning it off and back on in fall puts unnecessary wear on the ignition system. The gas savings are minimal, and you risk the pilot not relighting when you need heat in fall.
What does it mean if my pilot light keeps going out?
A pilot light that won't stay lit usually has a dirty thermocouple, a draft problem, or a gas supply issue. Try relighting it once following your manual. If it goes out again, call a technician — repeated attempts won't fix the underlying problem.
Is it safe to relight a pilot light myself?
Yes, if you follow your appliance manual exactly. The process is straightforward and safe. If you smell gas, the knob is stuck, or the pilot won't light after one attempt, stop and call a technician instead.
Do new furnaces have pilot lights?
Most new furnaces use electronic ignition instead of a standing pilot light. If your furnace has no pilot light, it's using electronic ignition and you don't need to worry about keeping it on.