If you're staring at that tiny blue flame and wondering do you leave the pilot light on a gas fireplace during the warmer months, you aren't alone. It's one of those classic homeowner debates where everyone seems to have a different opinion. Some people swear by keeping it lit 24/7 to keep the spiders out, while others can't stand the idea of wasting a single cent on gas when the sun is already doing plenty of work to heat the house.
The truth is, there isn't a one-size-fits-all answer. Whether you should keep that pilot light burning through the summer or click it off the second you stop needing the extra warmth depends on your specific setup and what you care about most. Let's break down the pros, the cons, and the weird little quirks of fireplace maintenance so you can decide what makes sense for your home.
The Case for Keeping It Lit
It might seem counterintuitive to keep a fire burning when you're cranking the air conditioning, but there are actually some pretty solid reasons to leave the pilot light on.
First off, there's the "spider factor." Believe it or not, spiders are weirdly attracted to the smell of the mercaptan that's added to natural gas. If you turn your pilot light off for six months, it's not uncommon for a small spider to crawl inside the pilot tube and spin a web. Those tiny webs are surprisingly strong and can completely block the gas flow. When you go to start your fireplace back up in October, you might find that the pilot won't light at all, and you'll end up paying a service tech a hundred bucks just to blow a bit of compressed air through a tube. Keeping the flame going keeps the "neighborhood" too hot for spiders to move in.
Another big reason is moisture. Fireplaces are usually made of metal, and they often sit against an exterior wall or connect to a vent that leads outside. During the humid summer months, cool air from your AC can hit the warmer parts of the fireplace and cause condensation. Over time, that moisture can lead to rust or corrosion on the burner and other components. That tiny pilot light generates just enough warmth to keep the internal components dry and stave off the "sweat" that can ruin your fireplace's internals.
Why You Might Want to Turn It Off
On the flip side, there are some very real benefits to shutting it down. The most obvious one is your wallet. Even though a pilot light is small, it's still consuming gas. Depending on local gas rates and the efficiency of your unit, you're probably looking at spending anywhere from $10 to $25 a month just to keep that tiny flame alive. If you multiply that by five or six months of warm weather, you're essentially paying for a nice dinner out just to keep a flame going that you aren't even using.
Then there's the heat issue. A pilot light might look small, but it's still a constant source of BTUs. In a smaller room, that little bit of heat can actually raise the temperature by a degree or two over time. This makes your air conditioner work just a little bit harder than it needs to, which is another sneaky way it adds to your utility bills.
One of the more annoying side effects of leaving the pilot on is the "white film" that develops on the glass. As the gas burns, it releases small amounts of sulfur and minerals. Over months of constant burning without the main fireplace being used, these minerals can bake onto the inside of the glass door, creating a cloudy, milky residue. If you don't clean it off regularly, it can actually etch the glass permanently. Turning the pilot off stops this buildup in its tracks.
What About the Cost of Gas?
Let's talk numbers for a second. If you're asking yourself do you leave the pilot light on a gas fireplace because you're worried about the bill, it's worth doing a quick check of your gas meter. Most pilot lights burn about 600 to 1,500 BTUs per hour. While that's peanuts compared to the 30,000 BTUs your fireplace uses when it's fully on, it adds up because it never stops.
If you live in a place where gas is cheap, you might not even notice the difference on your monthly statement. However, if you're on propane (which is usually way more expensive than natural gas), that pilot light is basically a slow leak in your bank account. In those cases, most people find it's much better to shut it off for the summer and just deal with the five-minute task of relighting it once the first frost hits.
Is It Safe to Leave It On?
Safety is usually the first thing people worry about when they see a flame burning unattended. Modern gas fireplaces are designed with this in mind. They have safety valves and thermocouples (or thermopiles) that are specifically built to handle a constant pilot. If the flame happens to blow out—say, because of a weird gust of wind down the chimney—the safety sensor will cool down and automatically snap the gas valve shut.
So, from a purely mechanical safety standpoint, you don't really have to worry about the house filling with gas if the pilot goes out. It's a very low-risk situation. The "danger," if you can even call it that, is mostly just the wasted energy and the potential for the glass to get hot enough to burn a curious toddler's hand if they happen to touch it.
The Middle Ground: The Summer Shutdown
If you're still torn, a lot of people opt for what's called a "summer shutdown." This usually involves turning the pilot light off sometime in May and then doing a quick maintenance check in September.
When you turn it off, it's a good idea to also close the glass doors (if they aren't already) and maybe even give the glass a good cleaning. This prevents that white film we talked about earlier from getting a foothold. When autumn rolls around, you'll need to relight it. If you've never done it before, it's usually just a matter of turning a knob to "Pilot," pushing it in, and clicking an igniter button. It might take a minute for the air to bleed out of the line, but once it's lit, you're good for another six months.
Actually, relighting it yourself is a good way to get familiar with your fireplace. It forces you to look at the burner, check for dust or debris, and make sure everything is in working order before the heating season really kicks into high gear.
Considering the Environment
If you're someone who tries to keep your carbon footprint as small as possible, the answer to do you leave the pilot light on a gas fireplace is probably a "no." Even though one fireplace doesn't seem like much, millions of pilot lights burning across the country add up to a significant amount of methane and CO2 being released for no functional purpose.
Many newer fireplaces actually come with "Intermittent Pilot Ignition" (IPI) systems. These systems use an electronic spark to light the pilot only when you turn the fireplace on, and then they shut the pilot off completely when you're done. If you have one of these, you don't even have to make a choice—the technology does it for you. But if you have an older "standing pilot" model, manually turning it off is your version of "flipping the switch" for the planet.
Final Verdict: What Should You Do?
So, where does that leave us? To be honest, there isn't a wrong answer here, just a "best for you" answer.
If you live in a very humid area or have a history of spiders clogging your gas lines, leaving the pilot light on might save you the headache and cost of a service call later. The $100 you save on a technician is more than the $60 you might spend on gas over the summer.
However, if you live in a dry climate, you're on a budget, or you just hate the idea of wasting energy, turning the pilot light off is the way to go. Just make sure you know where the instructions are for relighting it come wintertime—usually, they're on a little metal plate tucked under the bottom of the fireplace.
At the end of the day, your fireplace is there to make your life more comfortable. Whether that means keeping the pilot lit for convenience or shutting it down for efficiency is entirely up to you. Just give the glass a quick wipe once in a while, and you'll be ready for those cozy nights no matter what you decide.