Help your old fireplace get its spark back
Gas fireplace inserts are a popular supplemental heating option, largely because they’re more energy efficient than traditional gas fireplaces and cleaner than wood-burning models. If you’re thinking about adding one of these fireplaces to your house, you may be tempted to tackle the installation yourself. While you can handle some of it on your own, you need to recruit a professional for most parts of the job. Ready to get started? Let’s walk through how to install a gas fireplace insert in your home.
Safety note: Working with gas appliances is dangerous. A small mistake could significantly increase the risk of a fire, explosion, or gas leak, all of which can be deadly. We strongly recommend calling a pro to handle all the work for this job.
It’s important to take certain precautions to ensure you’re installing your gas fireplace insert safely and legally. Start by researching your local laws and building codes in regard to working with natural gas and installing fireplaces. You’ll need permits for this type of project, so secure those before beginning your gas fireplace installation.
Since you’ll be using your chimney to vent your new fireplace insert, it must be clean and in good working condition. If it’s not, it could lead to a house fire or fumes entering your home. To prevent this, schedule a professional chimney inspection and cleaning before installing the insert.
Once you’ve received your permits, you can begin installation. Here’s how.
Fireplaces—and fireplace inserts—come in a range of shapes and sizes. To determine the correct size insert for your fireplace, use a tape measure to measure the height, width, and depth of the fireplace opening.
You should also figure out how much heating output you need from your fireplace insert. Start by multiplying your room’s length and width to get its square footage. For a 12-by-10 room, that would be 200 square feet.
Depending on your climate zone, you’ll then multiply the square footage by between 30 and 60 to get the number of British Thermal Units (BTUs) required to heat your space. So, for a 200-square-foot room in a mild climate (like Texas), you’d need a fireplace with a rating of at least 6,000 BTUs.
However, colder climates and homes with less efficient insulation will need more BTUs. For example, if you live in an older house in Minnesota, you’d multiply the square footage by 60 (instead of 30). Based on these calculations, you can buy an insert that fits within your fireplace opening and provides adequate heating for your space.
Lay down a drop cloth in front of the fireplace opening, then put on your gloves and safety goggles. Your chimney sweep should have cleaned the fireplace during the pre-installation inspection, but if there’s any remaining debris or soot, be sure to remove it.
Now is the time to bring in professional help. You’ll likely need a couple of pros, including a natural gas plumber to connect the gas line and an electrician to run the wiring to your fireplace insert.
Before they leave, ask them to show you how to connect the gas line and wiring to the insert once it’s installed in the fireplace opening.
Follow your manufacturer's instructions on how to install the venting system. (Heads up: You’ll need a friend to help with this step—or better yet, a professional.)
While the specific steps vary by manufacturer, installing the venting system often starts with climbing onto your roof. If you’re afraid of heights, this might not be the right DIY job for you. If you choose to proceed, remember to follow proper ladder safety precautions.
From there, remove the chimney cap, drop the flue liner down the chimney, secure the exhaust and fresh air intake pipes to the insert, and install insulation around the pipes. You may also need to use tin snips to trim the extra material at the top of the liner and apply high-temperature sealant to secure the chimney cap.
Back inside, have your friend help you slide the insert into the fireplace opening. Your user manual should have specific instructions about how to position and level the insert within the opening, as well as information about minimum clearance requirements between the insert and its surroundings.
Connect the gas line and electrical components, then finish assembling the insert as outlined in your installation manual. Depending on your fireplace model, this could include things like attaching the gas fireplace surround, setting up the logs, or connecting the remote control.
Check for gas leaks by spraying the gas leak detector solution along the gas connection. If you see any bubbles, you have a leak. Don’t try to fix it yourself. Instead, call a professional who installs gas fireplaces.
This is also a good opportunity to test—or install—your smoke and carbon monoxide detectors and check the expiration dates on your fire extinguishers. If anything needs to be replaced, take care of it before lighting your gas fireplace for the first time.
After you finish installing the insert, book a professional fireplace inspection. Because you’ve modified your fireplace and chimney, you’ll likely need a Level 2 inspection, which is more expensive and labor-intensive than a basic inspection. On average, this type of chimney inspection costs $200 to $1,000.
The cost of installing a gas fireplace insert may be high, but it’s definitely worth it to ensure the safety of you and your loved ones. There are a couple of reasons why this isn’t a suitable DIY project.
For one, installing a fireplace insert requires you to work with gas lines, climb onto your roof, and move heavy equipment. All of these tasks are dangerous and potentially deadly. On top of that, you’re already hiring professionals for certain aspects of the job—namely, running the gas line and electrical wiring—so it makes sense to have a local gas fireplace company handle the entire installation.
When compared to wood-burning fireplaces, one disadvantage of gas fireplaces is their lack of ambiance. Specifically, they don’t offer the crackling sound and campfire smell that some people prefer. Gas fireplaces also require a gas line, which will increase your installation costs if you don’t already have one near your fireplace.
Based on the current national fuel prices, running a gas fireplace costs about $0.35 per hour if it uses natural gas or $0.62 per hour if it runs on propane. However, these figures depend on fuel prices in your area. For one heating season, it costs an average of $400 to $640 to run a gas fireplace, depending on your location and how often you use your fireplace.
