If you’re tired of cleaning out your chimney and tidying up wood, bark, and sap every spring, a gas fireplace insert could simplify your cleaning chores while still providing plenty of heat throughout the colder months. Gas fireplace inserts burn natural gas or propane instead of wood and are much more efficient than wood-burning fireplaces.
There are two types of gas fireplace inserts, each differing in how they obtain fresh air and what happens to the exhaust fumes. Some inserts use a direct-vent system, which is more expensive to install but safer and provides better air quality. These inserts require a supply pipe for outside air and also vent outside your home instead of into the room.
Ventless fireplace inserts are easier to install because venting is not considered. These inserts burn very hot and return the exhaust fumes back into the room, which is normally safe but can be risky if the insert malfunctions.Consider using carbon monoxide sensors in your home for additional safety.
Heat output is measured in British thermal units (BTU), with most providing between 8,000 BTU (enough to heat a bedroom or living room) and 40,000 BTU (enough to heat a large open concept space or tiny home).
With that in mind, we researched both direct-vent and ventless gas fireplace inserts from manufacturers like Duluth, Napoleon, Procom, and Ashley Hearth, evaluating each for aesthetics, vent and fuel types, heat output, and safety features to find the best options to replace any wood-burning fireplace.
Our Top Picks
Best Budget:
Best with Blower:
Ashley Hearth Vent-Free Fireplace Insert at Wayfair ($1,586)
Best with Mantle:
Duluth Forge Dual Fuel Ventless Gas Fireplace System with Mantle at Amazon ($1,234)
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What We Like
Durable cast iron construction
Lots of custom options
Lifetime warranty on parts
What We Don't Like
Vent kit sold separately
The Napoleon B46NTR is our favorite gas fireplace insert because it provides an experience remarkably similar to a wood-burning fireplace, plenty of customization options, and durable cast iron construction backed up by a lifetime warranty.
This direct-vented insert provides incredibly realistic flames with a 50 percent flame and heat adjustment that lets you stoke the fire or have it die down on command, with a pan-style burner that creates a varied flame pattern that looks more like a wood-burning fireplace than other gas models. Ignition is provided by a piezo lighter, and it also includes a remote for making adjustments from the comfort of your sofa or recliner.
Unlike the ventless fireplace inserts that make up most of our recommendations, this direct-vented insert creates circulation from outside air, which is pulled into the firebox through a pipe. The result is that the flames look more realistic and produce more heat. Two vent kits are sold separately (rear and top mount), so you may want to consider consulting with an installer to see which one you need.
This insert also offers several other options to customize your experience, including a blower to improve heat circulation, a wall-mounted digital thermostat, and two remote variants (both add on/off functionality, and one also includes a built-in thermostat). For further customization, Napoleon offers several optional media kits that you can swap out for different combinations of faux wood and rocks in the fireplace.
Vent Type: Direct | Ignition Type: Electronic | Heat Output: 24,000 BTU | Front Width: 29.6 inches
Best Ventless
Duluth Forge Ventless Gas Fireplace Insert
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What We Like
Remote control included
Can operate on natural gas or propane
Automatic shut-off
What We Don't Like
Smaller front dimensions
The Duluth Forge FDF300R Ventless Gas Fireplace Insert is our favorite ventless insert because it features an attractive rustic look, puts out a lot of heat, and includes an automatic shut-off for added safety. With its 26,000 BTU heat output, this fireplace insert can easily heat up to 1,300 square feet. It’s also a dual-fuel model, so you have the option of using propane if your home isn't already connected to natural gas.
We love the remote control that comes with this insert because you can easily turn on the flames and set a desired temperature from anywhere in the room. This insert also has an oxygen depletion sensor that helps offset the major drawback of ventless inserts, which is a vital safety feature that we look for in every ventless model that we recommend. When the sensor detects a lack of oxygen, it automatically shuts the fireplace off to prevent the dangerous accumulation of carbon monoxide in the room.
We wish this insert was slightly larger, but its compact front dimensions make it better for smaller homes and room layouts. The small size also gives you a lot of freedom in decorating since this is a zero-clearance model. If this unit is smaller than your fireplace, you can close the gaps with an attractive decorative mantel.
Vent Type: Ventless | Ignition Type: Battery-assisted piezo ignition | Heat Output: 26,000 BTU | Front Width: 29.1 inches
What is a piezo ignition?
A piezo ignition creates a spark by striking a crystal and lighting the gas fuel. "A button usually needs to be pushed and held while repeatedly striking the piezo igniter to create a spark," says Murphy. "Piezo ignitions are generally safe, as the spark is only produced when you intentionally press the button to start the fireplace." This type of ignition is opposed to electric ignition, which uses an electronically generated spark to light the gas.
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What We Like
Approved for use with any ventless log set
Zero-clearance firebox
Large front opening
What We Don't Like
Mesh draw screen can become hot
Log set not included
The ProCom Universal Ventless Firebox is a high-quality insert with a large front opening that costs significantly less than other options because it doesn't include a gas log set. That means it requires an additional purchase before you can use it, but you're free to splurge for a premium gas log set like the Duluth Forge DLS-18R-1 with realistic split red oak or keep your costs down with a less expensive option.
While this insert doesn't include a log set, it is equipped with gas line hookups, which simplifies the process of adding a log set of your choice. You can also purchase an optional blower for this insert for better heat dispersion if you find that you require more airflow to spread heat around your room.
This is a ventless insert, so it doesn't need a vent pipe. It technically doesn't even need a fireplace, since it’s also a zero-clearance model, but installation is simplified if you do have an appropriately sized fireplace to slide this insert into.
While this insert is basic in design, it has a large 42-inch front face that looks great when paired with an existing fireplace or custom-built mantle. We love the rustic aesthetic of the mesh draw screen, but we do worry about how warm this feature may get when the gas logs are ignited. You can always purchase an additional structured fireplace screen to prevent pets and children from getting too close to the flames.
Vent Type: Ventless | Ignition Type: Not applicable | Heat Output: Not applicable | Front Width: 42.5 inches
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What We Like
Zero clearance
Uses modern fireglass media
Attractive and weatherproof design
What We Don't Like
Configured for natural gas operation
If you're looking for an outdoor fireplace that you can use in your outdoor living room or patio, you need to choose a model that's capable of standing up to the elements year after year and putting out plenty of heat. We like this insert from Duluth Forge for outdoor use because it's made from 304-grade stainless steel that's both attractive and capable of standing up to the elements.
The stainless steel construction of this insert works well with the reflective fire glass media that are also capable of withstanding the elements year after year. The fire glass creates an attractive sparkling effect when the fire is active, and the flames also reflect off the stainless steel walls of the insert for an especially mesmerizing display at night.
This fireplace insert is also zero-clearance and ventless, so you can install it anywhere in your outdoor entertaining area without needing additional ventilation or clearance.It's configured for natural gas operation, but it includes a propane conversion kit that will come in handy if you don't have access to natural gas. The 24,000 BTU heat output is also more than sufficient for a screened porch or cozy outdoor living room, breathing new life into your three-season space.
Vent Type: Ventless | Ignition Type: Not listed | Heat Output: 24,000 BTU | Front Width: 31.6 inches
Best with Blower
Ashley Hearth Vent-Free Fireplace Insert
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What We Like
High heat output
Zero clearance
Durable steel construction
What We Don't Like
Industrial aesthetic
This vent-free fireplace insert from Ashley Hearth Products is ideal for large rooms, with a powerful blower and high heat output to match. It’s rated to heat up to 1,200 square feet, but the 34,000 BTU output and blower can provide warmth to a larger space in areas where the winters aren't too harsh. With that output, it’s well suited for use in a large living room, open concept space, or even a small home. The blower helps circulate air and spread heat, so this insert works well even if you have a chimney where heat might otherwise escape. It’s vent-free though, so you don’t need a chimney or vent pipe.
We aren’t in love with this insert's matte black industrial aesthetic, but you’re free to leave it exposed if you like it or cover it up if you don’t. It’s designed for use in zero-clearance fireplaces, so you don’t need to worry about installing it with a wood mantel or other flammable materials nearby. It includes an attractive log set and gas hookup hose, but you’ll need to supply your own standard millivolt thermostat.
Vent Type: Ventless | Ignition Type: Electronic spark | Heat Output: 34,000 BTU | Front Width: 38 inches
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What We Like
Thermostat and remote
Several wood finishes available
Automatic shutoff
What We Don't Like
Blower sold separately
This complete package includes a dual fuel fireplace insert from Duluth and an attractive wood mantle in an apple spice finish. The insert is similar to the Duluth Forge FDF300R (our best overall pick), but with a different grate and a higher output. It includes the same great oxygen sensor for protection against carbon monoxide, a remote control, and a thermostat with five heat settings. It’s also dual fuel, so you have the option to run this insert on either propane or natural gas.
This is a zero-clearance insert that’s designed to be slid into a fireplace, with the included mantle completing the installation for a seamless look. The fireplace features six hand-painted logs made from durable ceramic fiber, surrounded by a sprayed brick liner that looks very realistic. The surrounding mantle features light distressing for a lived-in look, with a number of finishes available. We like the warmth of the apple spice finish, but the nutmeg version is great, too, if you’re looking for something a bit darker.
Vent Type: Ventless | Ignition Type: Battery-assisted Piezo | Heat Output: 32,000 BTU | Front Width: 29.1 inches
Final Verdict
The Napoleon B46NTR is our pick for the best overall gas fireplace insert. This direct-vent insert produces incredibly realistic flames, comes with a remote control, and provides a lot of customization options. We also like the Duluth Forge FDF300R Ventless Gas Fireplace Insert (our best ventless pick). It runs on both propane and natural gas, comes with a remote, and has an oxygen depletion sensor and auto-shutoff feature for safety
What to Look for in a Gas Fireplace Insert
Fuel Type
When you're looking for a gas fireplace insert, it's important to consider what fuel you want to use. Some of the best inserts have a dual-fuel design, but others require a conversion kit or only work with one fuel.
Here are the fuel types used by gas fireplace inserts:
- Natural gas: This fuel is available in most areas, but it requires a gas line. If your house isn't already connected to natural gas, then you'll need to have a natural gas line installed. Natural gas is less expensive than propane, but having your home connected to natural gas can cost $2,000 or more, depending on your location.
- Propane: This fuel is available everywhere, but it needs to be stored in a tank at your location. Depending on the amount you use, you may want to opt for regular deliveries or to refill smaller portable tanks yourself. It's more expensive than natural gas, so it costs more over time to run a gas fireplace insert using propane.
"Propane is an excellent option for homes in areas without natural gas pipelines, as it is stored in tanks," says Ashley Murphy, fire and pool merchant at The Home Depot. "The flexibility to move or replace propane tanks as needed makes it a convenient option for some homeowners." The Duluth Forge FDF300R (our best ventless pick) is a dual fuel model, so you can use it with either natural gas or propane.
Vent Type
Gas fireplace inserts are available in ventless and direct-vent configurations. Selecting the right type for your gas fireplace insert will depend on the regulations in your area and whether you already have a vent system in place.
Vent-free inserts don't need to be vented because they burn hot enough to eliminate most harmful emissions. Exhaust fumes are vented directly into your home, so look for an insert that includes a low-oxygen shutoff. That's why these inserts need to include safety features like the automatic shutoff used by our best ventless pick, the Duluth Forge FDF300R.
Direct-vent fireplace inserts are more complicated to install, because they need to draw air from the exterior of your home and vent exhaust fumes outside as well. The Napoleon B46NTR (our best overall pick) uses this venting method, which results in higher indoor air quality and less chance for carbon monoxide to build up inside your home.
Natural venting is a third method, but nobody makes new systems that use it, so we don't recommend any naturally vented fireplace inserts. This method uses your chimney as a vent, which reduces the likelihood of carbon monoxide and other harmful substances building up in your home, but also has an increased risk of cold air entering through the chimney.
Size
Fireplace inserts are designed to slide into an existing fireplace, so it's important to make sure that an insert will actually fit before you buy it. The most common measurement to look at is the front width of the fireplace insert, which should be no wider than the opening of your fireplace.
For the best fit possible, measure the height, width, and depth of your fireplace and compare those measurements to the insert you're interested in. Fireplaces are angled, with the back being narrower than the opening, but fireplace inserts are designed with that in mind.
Expert Tip
It can be difficult to achieve accurate firebox or fireplace measurements with a standard tape measure. "Using a laser distance tape measuring tool allows you to determine your fireplace’s dimension with greater accuracy without the need to reach into the firebox," says Murphy. "The RYOBI 65 Ft. Laser Distance Measurer offers the versatility of five different units of measurement viewing options, all with simple one-button operation."
Heating Efficiency and Output
Gas fireplace inserts are significantly more efficient than wood-burning stoves, which release much of their heat directly up the chimney. Direct-vent and ventless gas fireplace inserts are both very efficient, with 90 percent or more of the heat they generate actually heating up your room. Keeping your gas fireplace clean will also ensure it operates at peak performance.
The heat output of gas fireplace inserts is measured in BTUs, so you can tell whether an insert will be able to produce enough heat for your room by looking at that number. "The ideal BTU requirement for effective room heating depends on the room's square footage," explains Murphy, "which is determined by multiplying the area of the room by 20, which produces the minimum BTU output necessary for heating."
As an example, a room that is 500 square feet would need a fireplace insert that can produce at least 10,000 BTUs. Other factors can also come into play, like the height of your ceilings and the quality of insulation in your home, but this is a useful place to start.
Our best with blower pick, the Ashley Hearth Products AGVF340N, has a heat output of 34,000 BTU. That's enough to heat a space up to 1,700 square feet according to Murphy's formula, but the manufacturer uses a more modest estimate of 1,200 square feet. For the sake of comfort, it's a good idea to opt for a slightly more powerful insert than you expect to need, and use a thermostat to keep it from getting too hot.
Why Trust The Spruce?
Jeremy Laukkonen is an updates writer for The Spruce with over a decade of experience writing about heaters, fireplaces, and other appliances. He's lucky enough to live in a climate where there's no need for fireplaces of any kind, but he has used electric fire place inserts in his own home previously. For this list, he researched ventless and direct-vent gas fireplace inserts from all the top manufacturers to find the best options for every situation.
Our Experts:
- Ashley Murphy, fire and pool merchant at The Home Depot
- Emma Phelps, an associate editor for The Spruce
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