We independently research, test, review, and recommend the best products—learn more about our process. If you buy something through our links, we may earn a commission.
A gas fireplace insert provides heat and flames without producing the smoke, soot, and ashes associated with a wood-burning fireplace. We spent hours researching dozens of fireplace inserts to find the best buys, assessing ease of installation, use, and maintenance.
Our top pick, the Duluth Forge Dual Fuel Ventless Gas Fireplace Insert, has an oxygen depletion sensor and remote control and can heat a large room.
Enjoy heat and flames on demand with one of these top gas fireplace inserts.
Best Overall: Duluth Forge FDF300R Vent Less Gas Fireplace Insert
Venting Type: Ventless | Fuel Type: Dual Fuel | Front Product Width: 29.1 inches | Material: Ceramic | Heat Output: 26,000 BTU/hour
Includes remote control
Heats up to 1,350 square feet
Oxygen depletion sensor
Lacks a thermostat
Heat your room in a hurry with the help of the 26,000 BTU per hour Duluth Forge Vent Less Gas Fireplace Insert. This model is sized for heating spaces up to 1,350 square feet and requires no external venting. As a safety precaution, an oxygen depletion sensor (ODS) monitors air quality and will sound an alarm if oxygen levels become low.
You can slide the Duluth Forge Vent Less Gas Fireplace into your existing masonry fireplace (with appropriate ductwork) or build a fireplace to suit this insert exactly. Its remote control makes starting a fire as simple as pushing a button: Unlike a wood-burning fireplace, there are no matches or fire starters needed.
Best High-End: Kingsman Fireplaces IDV33 Direct Vent Fireplace Insert
Venting Type: Direct Vent | Fuel Type: Natural Gas | Front Product Width: 34.5 inches | Material: Metal | Heat Output: 31,000 BTU/hour
Blower with variable speed settings
Option for louvered or solid surround
Equipped with safety screen barrier
Lacks dual fuel flexibility
More heat loss to flue than ventless models
Choose the features and options that matter the most to you with this high-end gas fireplace insert from Kingsman Fireplaces. With both natural gas and propane fuel options, you'll also get to decide whether to upgrade to IPI (immediate ignition) or standard millivolt ignition, which takes up to 30 seconds to light. As a direct vent model, this insert sends exhaust up your existing chimney with a chimney insert or horizontally through an exterior wall with special ductwork.
While many gas fireplace inserts have a uniform appearance with a black metal surround and rustic-looking logs inside, this splurge-worthy option offers more choices. You can choose between a louvered or solid surround, a traditional log set, or contemporary crushed glass interior, and either black, pewter, or copper exterior finish. No matter which style you choose, the functional features of this gas fireplace insert make it a smart buy—a heat-activated blower with variable speed control distributes warm air into the room, a safety screen provides added protection, and a remote gives you quick control from anywhere in the room.
Best Budget: Pleasant Hearth PHZC32F Vent Free Gas Firebox
Venting Type: Ventless | Fuel Type: Natural gas or propane | Front Product Width: 32.19 inches | Material: Metal | Heat Output: Not applicable
Zero clearance insert
Includes draw screen for safety
Must buy a set of gas logs
Decorative brick panel insert sold separately
Many gas fireplace inserts are sold as a complete package, including a log set with a burner or other filler material. However, another option to save money or customize the look of your gas fireplace is to purchase a gas firebox without logs. You can add the log set of your choice or other filler material (like crushed glass) and a burner.
For an affordable gas fireplace insert, choose the Pleasant Hearth Vent Free Gas Firebox, which is priced several hundred dollars cheaper than many other popular models. It offers zero-clearance installation options, a fire screen for safety, and it can be used with either natural gas or propane log sets. While you still need to purchase the log set to make this gas fireplace insert functional, you’ll be able to choose components that fit your style and budget.
Best Direct-Vented: Empire Tahoe Deluxe Direct Vent Fireplace
Venting Type: Direct Vent | Fuel Type: Natural Gas | Front Product Width: 37 inches | Material: Metal | Heat Output: 20,000 BTU/hour
Only 16 inches deep
Includes brick liner and logs
Not equipped for dual fuel
Barrier screen or door set sold separately
A direct-vented gas fireplace insert creates more versatile installation options since it can be vented horizontally or vertically. It also offers the advantage of using the outdoor air for combustion, rather than drawing in warm air from the room you'd like to heat.
The Empire Tahoe Deluxe NG Millivolt Fireplace provides up to 20,000 BTU of heat using a natural gas supply. It features a brick liner and six ceramic logs for an authentic fireplace look. The glass front provides a sealed chamber for combustion, but take note that the glass can become very hot to the touch. You’ll need to buy a barrier screen or door set for protection against touching the hot glass. This fireplace insert measures 37 inches wide but only 16 inches deep, allowing it to fit into shallow fireplace openings.
Best Natural-Vented: Empire Comfort Systems Deluxe Keystone Series B-Vent Fireplace
Venting Type: Natural vent | Fuel Type: Natural gas | Front Product Width: 37 inches
Material: Metal | Heat Output: 21,000 BTU/hour
4-inch exhaust vent
Log set included
Blower is a separate accessory
Natural-vented gas fireplaces vent vertically, like the chimney on a standard fireplace. Also sometimes referred to as a B-vent fireplace, this type of gas fireplace insert pulls air from inside the room while exhausting it up and out of a chimney outfitted with the proper ductwork. The result brings large, bright flames that more closely resemble a wood-burning fire than direct vent or vent-free models of fireplace inserts.
The Empire Keystone Deluxe B-Vent Fireplace measures 37 inches wide, while the B-vent is just four inches in diameter. This fireplace includes a brick-look liner and a set of logs for a cozy ambiance all year long. It has an output of 21,000 BTU using a natural gas supply. Generally speaking, natural-vented gas fireplace inserts are ideal for heating smaller rooms. They provide warmth while exhausting fumes but won’t overpower a room with too much heat like some direct vent models.
Best Log Set: Duluth Forge Ventless Dual Fuel Log Set-24 in 33,000 BTU
Venting Type: Ventless | Fuel Type: Natural Gas or propane | Front Product Width: 18, 24, or 30 inches | Material: Refractory ceramics | Heat Output: 33,000 BTU/hour
Realistic shape and texture
Battery-assisted Piezo ignition
A gas log set can be used along with a fireplace insert or inside an existing wood-burning fireplace. The Duluth Forge Ventless Dual Fuel Log Set can use natural gas or liquid propane, offers eight realistic, hand-painted logs cast from refractory cement, and can warm a room up to 1,300 feet. Gas log sets come in vent-free and vented varieties; this set is a ventless option that does not require a chimney or duct to dispel exhaust.
This set is available in 18-, 24-, and 30-inch widths, so be sure to pick the set of gas logs that fits your firebox or fireplace. All sizes feature a battery-assisted Piezo ignition with a built-in pilot oxygen depletion sensor (ODS), so it will immediately turn off if it detects carbon monoxide or lack of oxygen.
The Duluth Forge FDF300R Vent Less Gas Fireplace Insert (view at Amazon) is a practical choice for most homeowners. This ventless model puts out plenty of heat with up to 32,000 BTU and offers dual fuel options. However, if you are looking for a natural-vented option that exhausts through an existing chimney, then consider the Empire Keystone Deluxe B-Vent Fireplace (view at Amazon). This option only outputs up to 21,000 BTU, but natural-vented gas inserts tend to produce more realistic-looking flames.
What to Look for in a Fireplace Insert
One of the most important things to know when buying a gas fireplace insert is the type of vent configuration you need. There are three primary venting types: natural-vented, direct-vented, and ventless. In short, natural-vented gas fireplace inserts require vertical ductwork terminating at the roofline, direct vent models can use vertical ductwork terminating at the roof or horizontal ductwork through an exterior wall, and ventless models require no ductwork for exhaust.
Gas fireplace inserts require either a natural gas line or a propane tank for fuel. Natural gas units often produce more heat (measured in BTU per hour), but they need to have a gas line installed. Propane tanks avoid the need for gas line installation, but they require regular replenishment.
Gas fireplace inserts have varying percentages of heating efficiency, largely dependent on the unit’s venting type. Natural-vented fireplace inserts have the lowest heating efficiency since heat is lost through the open damper or flue. Direct vent fireplace inserts have better heating efficiency because they draw in outside air and use smaller ductwork for exhaust. Ventless gas fireplace inserts have the best heating efficiency since they have no ductwork. Most units operate with 99 percent efficiency and produce a minimal amount of carbon monoxide. However, it is important to monitor oxygen levels in a room with a ventless gas fireplace. In most cases, these types of inserts come equipped with an oxygen depletion sensor.
Can you install a gas fireplace yourself?
In most cases, the installation of a gas fireplace is best done by a professional. Some parts of the project, such as the carpentry work to install the firebox and trim might be within DIY capabilities, but other work—like installing exhaust vents, running a gas line, or installing a new electrical circuit—will often require the help of a professional.
How much heat does a gas fireplace provide?
The amount of heat produced by a gas fireplace insert is measured in BTU, short for British Thermal Units. Heat output varies by model and fuel type, but most gas fireplace inserts produce between 20,000 and 40,000 BTU (some have much higher or lower outputs).
Keep in mind that heating efficiency is an important factor to consider since this percentage will determine how much of the heat reaches the room and how much is lost to the venting process.
How often should you clean a gas fireplace?
Generally speaking, you should clean your gas fireplace monthly. While it’s true that gas fireplaces are much less messy than the soot and ashes that come from a wood-burning fireplace, there are still by-products from the combustion process that require cleaning. In addition, cleaning your gas fireplace insert gives you an opportunity to inspect components for any damage that may affect the operability or safety of the unit.
How do you remove a gas fireplace insert?
While actually removing the gas fireplace insert isn’t overly complicated, properly disconnecting and capping the gas line is critical. For this reason, most people hire a professional to handle the work on the gas line or take care of the entire process to remove the gas fireplace insert.
However, here is a basic overview of the process to remove a gas fireplace insert: First, shut off the gas supply. Next, remove the trim pieces around the insert. At this point, you can unscrew the gas supply line from the insert. Gently free the insert from the wall or masonry—this step will often require a second set of helping hands. Finally, cap the gas line and test it to ensure there are no leaks.
Why Trust The Spruce?
With more than five years of researching the best products for indoor and outdoor living, Erica Puisis is familiar with the features and benefits that matter the most to homeowners. Her areas of expertise have included home heating and cooling systems and appliances. To find the best options for gas fireplace inserts, she compared the venting type, maximum BTU output, and fuel type of each model considered. All of the options considered provide at least 20,000 BTU of heat, and most are available for natural gas or propane connections.