Home & Garden

Here's how to maintain your home's gas fireplace

Get cozy—but get it clean first

How to use and clean a gas fireplace Credit: Getty Images / Aschen

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Since vacations are inadvisable this year, lots of people are investing in bringing their vacation to their back porch with previously-seen-as over-the-top additions like bar stations, couch hangouts, and gas fireplaces.

Whether you're the new owner of such a gas fireplace, or if you're just planning to install one inside your home before the upcoming winter unleashes polar vortexes and heavy snowfall, it's important you do your research on how to use, maintain and clean a gas fireplace.

As with any home fixture that harnesses fire, there's a lot that can go wrong if you haven't done the required reading first. Or, if you want the Spark Notes version, you can just read through this summary to cover your bases.

How does a gas fireplace work?

One of the more important steps to properly using a device is having a general understanding of how it works. This allows you to recognize many of the hazards before they become dangerous. You can also find out how to fix them quickly and safely.

While there are many different kinds of gas fireplace, they all typically operate in the same way, by drawing in and then igniting natural gas from your local utility. Sounds simple, right? Well, the basics are easy to understand, but this is where the "many different kinds" part comes into play.

Your gas fireplace might come with a control panel, a key valve, or a wall switch, all of which have different steps to actually light the fire (we'll go over these in a bit). You'll also need to decide whether you want a full installation, a ventless model, or an insert.

Full-installation gas fireplaces

These are by far the most common and probably what you think of when you picture a fireplace. The discreet installation is typically built into a wall and consists of a main hearth area surrounded by a buffer to keep the rest of your house from catching fire, typically with a mantle on top.

These models feature complex circulation technology to help keep more of the heat in your home instead of simply venting it outside with the exhaust.

When it comes to venting, there's three major types: direct, natural, or power.

Direct vents draw in outside air to aid combustion and funnels all emissions through an exhaust hose. This sealed system is efficient, maintains your indoor air quality, and safely expels some of the more problematic byproducts.

Natural vents (or B-vents) draw in air from the room to aid combustion, then exhaust through a pipe. The biggest difference here is natural vents aren't a sealed system, which has a few implications but basically boils down to being a bit less efficient than a direct vent.

gas fireplace
Credit: Getty Images / Bob Steiner

Gas fireplaces are often a clean, inexpensive way to heat your home.


The third style, power, uses an electric fan to force exhaust out, instead of relying on the natural pressure differential created by the fire's heat. This vent system allows you to be a bit more flexible on where you can install the fireplace, as the fan allows the ventilation tube to have multiple bends or even vent underneath the fireplace.

Ventless gas fireplaces

Since natural gas burns relatively cleanly, some gas fireplaces don't bother with the vents at all, simply expelling the carbon dioxide and water vapor into the room around them.

These ventless fireplaces, while much easier to install and capable of harnessing all of the heat produced, also aren't the safest—there's a good chance they might be outright illegal in your area. Laws vary from city to city, but you're definitely out of luck if you live anywhere in Canada, California, or Massachusetts.

Assuming they are legal where you live, we'd still recommend operating one in a well-ventilated area, not only to avoid carbon dioxide build-up, but to help disperse some of the humidity—for every gallon of gas your fireplace consumes, it will exhaust about a gallon of moisture.

Gas fireplace inserts

The final option for gas fireplaces is the insert. These modules are typically meant to be installed into an existing, wood-burning fireplace. Since they utilize the existing masonry, they're typically a cheaper option—on their face at least. Unfortunately, you're going to run up against several potential problems with this style of fireplace.

As we mentioned, gas mostly burns into carbon dioxide and water vapor—but that water vapor can pose several problems. For starters, the water vapor is slightly acidic, which can gradually eat away at the brick and mortar inside your chimney. Also, if you're venting out a chimney, chances are there's not enough heat getting vented to prevent the water from condensing, which can lead to water dripping back down and into the fireplace. Before installing this kind of gas fireplace, it's best to consult with a professional and possibly get some insulated liner installed.

How to light a gas fireplace

Before you begin

Before you start applying fire to flammable gasses willy-nilly, you'll need to make sure you're familiar with the particular unit you have. Each unit requires different tools to keep things safe.

If you need to manually start the fire, like most systems that use fireplace keys, you'll need long matches or a lighter with enough of a barrel to keep your hand at a safe distance. You'll also want to remove any decorative flourishes that may be on or around the fireplace. Many fireplaces come with decorative screens or covers that should be removed before use.

You'll also want to get in the general habit of sniffing around for gas smells, particularly near the ground as natural gas is heavier than air. You don't want to start lighting fires if there's lingering gas present. Smelling gas when you shouldn't could be an early warning that there's some kind of leak—if that happens, shut off the gas at the source and call for a professional to check your system's integrity.

Using a wall switch to turn on your gas fireplace

As you may have guessed, this is generally the most straightforward procedure, often just requiring the flick of a switch to get the fire started. Once everything is lit up, there may be a dial or knob you can use to adjust the size and strength of the flames. If the switch doesn't ignite the fire, this can mean something is wrong, either with the fireplace or with your electrical system. Check the instruction manual and call a professional if you can't figure what's wrong.

maintenance
Credit: Getty Images / sturti

If you notice a problem with your gas fireplace, it's often best to contact a professional rather than trying to fix it yourself.

Lighting a gas fireplace via control panel

Every control panel is different, but most typically have a pilot knob, igniter button, and a dial to adjust the flame's strength.

First, you'll want to locate the pilot knob. These can have multiple settings, but to start, turn it from the "off" position to "pilot." If the pilot knob wasn't set to the "off" position to start, then you'll want to turn it off and wait a few minutes for any lingering gas to clear out. Once you've set the dial to "pilot," you can typically push in the pilot knob to manually feed gas into the system.

This preps your fireplace for the next step—pushing the igniter button—which you'll want to do once per second until it lights. This may take several attempts before the pilot properly lights. After it lights, you'll want to keep the pilot button held down for a bit—maybe 30 seconds or so—just to ensure everything is warmed up and the flame is able to stay lit.

At this point you can turn the knob from the "pilot" setting to "on." This starts the flow of natural gas, which should ignite on the pilot light, bringing your fireplace roaring to life. Adjust the flame as you'd like with whatever other settings the control panel offers.

Lighting a gas fireplace with a key valve

If you have an older fireplace or simply like rustic fixtures in your home, you probably have a key valve system. This one is typically the most manual operation of the bunch.

To start, you'll need your key, be it a hex key or something more old-time to match the rest of the aesthetic.

Next you'll want to locate the slot, typically to the immediate left or right of the fireplace, but sometimes it can be on the floor.

Have your fire starter ready—a long match stick or a lighter. You'll want to hold your flame near the burner, then slowly turn the key to open up the gas valve. You may need a friend to help you out with this step. If the gas valve happens to be far away from the fireplace, you may not be able to hold both the match in place and turn the key.

It should light immediately, at which point you can use the key to adjust the height of the flames.

Turning off your gas fireplace

No matter the location of your gas fireplace—porch, patio, or living room—it's likely that it will go unused for months or a full season at a time. In this case, turn off your pilot light to help reduce your gas bill and generally make your home a bit safer.

To shut off the pilot light, turn all control knobs to the "off" position and close the emergency gas valve. If your system uses a key, make sure to turn the key until the valve fully closes.

How do you clean a gas fireplace?

cleaning
Credit: Getty Images / Bill Oxford

Routinely cleaning your gas fireplace is an important bit of maintenance that can keep need for more significant repairs at a minimum.

After some use, you might notice your fireplace isn't looking quite as clean and fresh any more. Fortunately, cleaning your fireplace is pretty simple once you know what to do. Turn off the gas and ensure that the fireplace's interior is cool to the touch. You'll also want to review the manufacturer's guidelines for any special instructions (or to ensure you aren't voiding your warranty).

When you're ready, remove the glass in front of the fireplace proper. This can be tricky, as it's heavy, awkward to move around, and delicate. It's good to have a few towels laid out beforehand so you have a thick, soft landing pad you can gently place the glass onto once it's removed.

Clean the glass with undiluted vinegar, as that can eat through cloudiness and won't leave behind any residue you wouldn't want around flames.

If that's not cutting it, there are fireplace-specific cleaners. Again, avoid general-purpose cleaners, as they weren't designed with fire in mind. When time comes to replace the glass, make sure it's completely dry. If it's not, there's a chance you could run into issues with breakage or cloudiness once you apply heat again.

As for the fireplace itself, you'll want to start by removing any grating from above or below the main cavity. You'll probably see a bunch of dust and cobwebs, nothing a vacuum with a narrow attachment can't handle.

Inside the main cavity, you'll want to remove the faux logs and any mineral wool insulation, making sure to take a picture first so you remember how they were arranged. As you remove the mineral wool, be sure to shake off any debris that may be stuck to it.

Once everything is out, you can clean up any soot along the burners with a cloth or soft-bristle brush. Again, we'd recommend sticking with vinegar or fireplace cleaner.

If you're seeing more soot than usual, that could be due to a clog in your gas line producing areas where the flame is burning hotter and dirtier than it should. Check that the lines are clear and call a professional if necessary.

Once everything looks clean as a whistle, you can put everything back together, making sure to reposition the mineral wool and logs in whatever configuration they started. Replace the grates, and gently slot the glass back into place.

Outdoor gas fireplace maintenance

If you decided to go for an outdoor gas fireplace, there are a few other considerations you'll have to make when it comes to routine maintenance. While outdoor fireplaces are pretty weatherproof by design, that doesn't mean they're completely impervious to everything mother nature can throw at it. In addition to keeping it covered when it's not in use, it's a good idea to routinely check for signs of settling, cracking, or crumbling.

Even though most outdoor gas fireplaces will be installed on a porch or patio, settling can still occur over time, especially in places that have repeated thaws and freezes throughout the winter months. The cycle of thawing and melting can get water deep underground and potentially making the area less stable over time. A quick check with a basic leveling tool should be enough to keep an eye on this problem.

Cracking and crumbling can occur when your outdoor fireplace is exposed to extreme heat and sun or particularly wet and cold conditions. In the former case, some of the materials may dry out and become more brittle or porous, which can cause them to chip easily; in the latter case, materials can become saturated in water, causing breakage when it freezes or allowing plant or fungal growth in perpetually soggy nooks and crannies. If you see this happening, it means you'll probably have to keep it under a tarp more frequently than you currently are, or that there's some problem with your fireplace's sealant. Fixing this might require buying some sealant of your own and giving the affected areas a fresh coat.

Now all that's left is to sit back, relax, and enjoy the unique coziness that only a fireplace can bring.


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