Best Gas Fireplace Inserts of 2021 – A Comprehensive Guide

There’s no denying that the fireplace is the centerpiece of many homes and the traditional open fireplace can look stunning, yet they have a fundamental flaw – they aren’t as efficient as gas fireplace inserts.

These relatively modern heating innovations offer a simple solution to improve your home heating instantly and affordably.

After putting in 50 hours of research, comparing more than 100 gas fireplace inserts and testing seven of the best models, we believe our recommendations are worth taking into account.

After all, selecting the right model for you and your home can be a difficult decision to reach with so much jargon and choice on offer.

If you have any questions regarding the information on this page or any of the gas fireplaces we discuss, then feel free to share them in the comments section and we’ll try to answer you as best as we can.

Quick Picks: Best Gas Fireplace Insert Reviews

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What is a Gas Fireplace Insert?

A gas fireplace insert consists of a normal gas fireplace enclosed within a metallic firebox that is surrounded by a steel case, which is designed to fit into a masonry fireplace. The main purpose of a gas insert is to make your masonry fireplace more efficient, which, by comparison,  are inefficient and polluting.

They do this by utilizing the heat produced in a more conservative way. They achieve this by containing the majority heat produced from the gas within the metallic insert casing, which is then gradually radiated into your living space instead of being quickly lost up your chimney and into the surrounding masonry.

Air from your living space will also flow into space between your firebox and steel case to be heated, increasing its efficiency further.

Frequently, the heat is also recirculated into your home with a stove blower. This gradual dispersal of heat prevents it from being lost up your chimney and the blower prevents heat being isolated to a single “heat spot” in your living area. Since heat rises, the heat spot will generally be just beneath your ceiling.

The best gas fireplace inserts are exceptionally efficient, commonly producing between 25,000 to 40,000 BTUs, which is ample to comfortably heat a medium-size room. While their energy efficiency ratings range from 70 percent to 80 percent.

There are many types of gas fireplace inserts, but the best ones are usually equipped with a selection of innovative features that provide ease of use and optimum heating performance.

These include remote controlled models where the thermostat can be easily adjusted with the click of a few buttons, additionally, there are specialized models that can be fitted into an electric fireplace and natural gas fireplace inserts that remain popular.

Will Your Existing Fireplace Be Compatible With A Gas Fireplace Insert?

Today the vast majority of inserts have been designed so that they can easily fit with most fireplaces, however, the majority doesn’t mean all.

Therefore, prior to choosing an insert, you need to measure the dimensions of your fire to ensure it will be a snug fit. The opening of your fireplace is an important measurement is to determine the size of your fireplace opening as this will let you know what size surround you will require in order to install your insert.

Most inserts come in the usual sizes – small, medium, and large. Therefore you need to measure all of the dimensions of your fireplace, not only to make sure the insert will fit but to see which ones available match your taste and dimensional requirements.

Therefore the measurements you ought to take note of include the width of the back and the front, and the depth from the front to the back. A common measurement people overlook is the distance from the firebox to the mantel, this is essential to ensure you get an insert that functions effectively.

Once you’ve determined the dimensions of your fireplace you can proceed with searching for your preferred model. Thanks to the popularity of inserts more manufacturers than ever are producing different designs that can meet the style demands of the modern consumer.

Types Of Gas Fireplaces Vs. Inserts

1. Log Sets

These are the most inexpensive variety of gas fireplaces and as the name suggests are simply composed of artificial logs made from materials such as ceramic. They are the easiest to install, typically requiring a simple connection to the main gas supply.

In order to operate one safely, you will need to have an operational flue in your chimney structure to ventilate your home and remove toxic fumes such as carbon monoxide.

Although easy to install and affordable, they don’t tend to be opted for by those who are serious about heating. They are typically used for decorative purposes and by those who reside in warmer climates and thus require less heating throughout the year.

2. Gas Fireplace Inserts

As the name suggests, gas fireplace inserts are conveniently inserted into a pre-existing fireplace hearth or wall cavity. In order for a fireplace insert to be installed, the fireplace has to conform to local regulations and codes.

In essence, an insert is very similar to a log set, in that it still produces heat in the same way, but it is surrounded by a metal casing. The casing the gas burning unit sits within contains a cavity, similar to the principle of a cavity wall. This cavity contains air that is warmed by the fire and gradually circulated into the living space evenly.

Although more expensive than log sets, they are certainly more efficient and offer a more practical solution for those wanting to produce a good amount of heat. Unlike a log set, the heat isn’t lost to the environment so easily either, instead, it is trapped within the cavity and slowly dispersed.

3. Zero Clearance Fireplaces

A Zero Clearance Gas Fireplace is a firebox unit used when constructing a new fireplace. Also referred to as “factory built fireplaces”, since they are pre-built in a factory and installed later, as opposed to being constructed on location like traditional fireplaces.

These are popular choices due to them often not requiring a functioning chimney – although there are vent options, as well as the vent-free variety. These work in a similar way to inserts and often contain metal casing and a blower to circulate warm air.

Although, popular due to their easy installation, they aren’t as clean looking as inserts, since they are often built against a wall as opposed to inserted within a wall cavity.

What Should You Look For In A Gas Fireplace Insert?

When choosing an insert for your gas fire you want to look for the best features that are designed to optimize and improve the function of your insert, the most popular innovations offered by modern manufacturers include:

Circulation systems the majority of models offered come accompanied with some form of circulation systems that serves to circulate the heat uniformly throughout your home. It’s pretty important that you and your family feel the heat, so always look for a good quality insert that features a stove blower or a stove fan.

Flame control certain models allow you to adjust the size of the flames you can see in the viewing window and although this isn’t essential it can certainly be aesthetically pleasing.

Thermostat control the best inserts come with thermostat control, this is incredibly useful as it allows you to easily adjust and control the temperature range and have the reassurance that your insert will turn on when your home gets cold.

Electronic ignition In addition to providing convenience, it also removes the need for a pilot light, saving up to $10 a month in fuel.

What Type Of Venting Can You Install With An Insert?

There are two major types of fireplace inserts – vented and vent-free. The kind of venting you are able to install in your fireplace is usually the deciding factor to what insert you choose. Although a gas fireplace doesn’t emit smoke or odors, it does produce pollutants including carbon monoxide and nitrogen.

Vented will feed these emissions to the exterior, while vent-free options will direct them into your living space. This venting also applies to other gas appliances such as gas water heaters.

Direct-Vent Inserts

As you may be aware, most fireplaces are installed within a central chimney or on the exterior walls of your home. Direct-vent gas fireplace insert models feature vent inserts which are placed up the chimney, you will require one vent tube for clean air coming inwards and one for exhaust fumes. This is the safest, most efficient venting method also known as a two-pipe system.

You will typically need a collar plate and cap on the chimney as well as a chimney liner. If you have an electrical fireplace then you won’t need any venting at all, this is because there is no fire and therefore no exhaust fumes. An electrical insert is the easiest option if you don’t have a functioning chimney or venting.

Vent-Free Inserts

Ventless gas fireplace inserts enable you to use the insert without the need of a chimney or ventilation. This is ideal if you have a home without a functioning chimney, additionally, heat won’t be lost via a vent with a vent-free option so it’s definitely worth considering for those without the funds to install venting.

However, it is worth noting, that many observers in the industry feel that vent-free inserts aren’t safe. As although modern models do feature helpful technology such as oxygen depletion sensors and catalytic converters.

Many have expressed that the potential risks outweigh the advantages. Besides, it’s not difficult to install a chase and cut a hole in an exterior wall for a direct-vent model. Ultimately, this is a decision for you to make.

A chimney liner kit is often an affordable way to install ventilation for a gas fireplace. However, if you still want to use gas but you have a limited budget, then you may want to consider a propane heater, these economical and often portable heating systems are also ideal for heating outdoor patio spaces and poorly insulated outbuildings such as sheds and garages.

Top Picks: Best Gas Fireplace Insert Reviews

Appearance and Design 

Founded in 1976 by Wolfgang Schroeter, Napoleon fireplaces is a world leader in the heating sector, with a five-star reputation to match.

The GVF36-2N by Napoleon is a large ventless gas fireplace insert that is ideal if you want to increase the efficiency of your natural gas fireplace.

The fire’s design brings both the traditional charm of the natural wood burning logs with dynamic dancing flames as well as a contemporary touch thanks to the outer metal casing and black louver kit, perfect for people who want the benefits of both form and function.

The great thing about Napoleon is that they provide the ability to customize your fireplace in multiple ways, which is great if you are looking to match your fireplace to a specific interior design décor.

This includes additional trims and surrounds that can be purchased for the fireplace, as well as various trivets and louvers, ideal for those looking for the ability to make a basic fireplace look extra special.

Heat Output & Efficiency

With this vent-free gas fireplace insert, you can achieve a heat output as high as 30,000 BTUs, which is ideal for small to medium-sized homes. This model allows you to easily adjust the heat output by controlling the flame by up to 50% for maximum heat adjustment, maximum comfort, and maximum efficiency.

This control will be especially welcome during winter when the temperature starts to drop. The best part is you can adjust it and turn it off from the comfort of your seat thanks to the digital remote control.

The black fireplace louver kit is also included with the GVF36-2N, which increases the air circulation inside your fireplace and adds a crisp visual element.

Safety Features

Overall, gas is a very clean fuel, with very few pollutants and toxic emissions when compared to other fuel sources. However, carbon monoxide gas that is odorless is a real danger to gas fuel users, which is why its good to know that this model by Napoleon comes fitted with an oxygen depletion sensor.

This shuts the pilot off before oxygen drops below a safe level. This safety feature is a wise investment and must-have feature for the modern gas fireplace user.

This model also comes with a handy safety screen that can be easily detached, which is designed to act as a barrier, keeping your family safe from contact with the intense heat of the open flame.

Although this is not heat proof itself, so caution must still be exercised, especially when concerning animals and children. Still, it is certainly a welcome level of extra protection.

Perhaps one of the downsides of this model is the absence of a ceramic glass window, which in our view would increase safety.

However, you can easily make use of the safety screen that’s included and if you have a young family or pets, then a safety gate is always advised in any case. Having said that many people prefer having no window panel as they enjoy viewing the naked dancing flames, so this is largely down to personal preference.



Duleth Stove and Fireplace was founded back in 1992 by Matt Boo and Jason May, who were both residents of Duleth and had years of experience in the hearth industry prior to deciding to design and manufacturer their own products.

Today Duleth holds a fantastic reputation and 5-star customer reviews are standard for their collection of hearth and fireplace products.

Appearance & Design

The Duluth gas fireplace insert is available as a standard insert that includes a burner, logs, and thermostat remote control. There’s also the option of paying a little more and purchasing it with various wooden surrounds, including the wood colors oak, tobacco, and cherry, ideal for those without an existing stone masonry fireplace.

Since this fireplace is vent free, it can be installed without a chimney, however, please check local codes as some states, such as California do not permit ventless fireplaces.

Heat Output & Efficiency

The fireplace itself is designed to look like a traditional log fire, which it pulls off quite well when in operation. You can add a surround to this fireplace quite easily, however, bear in mind that it does require a fireplace clearance of at least 1/2 inches.

The fireplace also comes packed with an array of tech to increase its efficiency and ease of use, including a remote control, electronic ignition to the pilot and a blower to circulate the warm air evenly throughout your home.

The heat output of the fireplace is an incredible 32,000 BTU’s, which is superb for the price point and ideal for heating small to medium sized spaces of around 1,500 square feet. The instructions also state that this fireplace can be used with liquid propane (LP) in which case the installer needs to leave the blue plug inserted into the rear of the gas valve.

The blue insert depresses the valve’s internal plunger which allows the LP to flow through the valve and without that piece inserted the valve does not open. This is a straightforward process and you are provided with everything you require, which is great for the price.



Founded by Michael Mulberry – Sure Heat has a long history and a wide-ranging amount of different hearth, barbecue and patio products on offer.

They were one of the pioneers of modern wood log sets and first began experimenting with their development back in the 1980’s. Today, they are a leader in the field and a highly trusted brand in the US and across the globe.

Appearance & Design

The Burnt River Oak insert offers a great solution for homeowners interested in converting an inefficient traditional wood burning fireplace into a more efficient gas fireplace without the need for a costly remodel. 

This unit will help to transform the appearance of a traditional fireplace as it realistically creates the look of a mature wood burning fire. These logs are extremely high quality and have attention to detail in mind, which unfortunately can’t be said about many other log sets on the market.

They are made from ceramic, an extremely heat-resistant material and have been hand painted in great detail to give the impression of genuine wood logs. The detail and size of these logs are great for the price point.

Selection Of Sizes

This gas log set is available in two sizes – 18 and 24 inches. The set itself has been designed to fit fireplaces with dimensions of at least 36-inch front width; 15-inch depth; and 25-inch back width, so make sure to measure your fireplace before ordering.

Safety Features

This log set is Canadian Standards Association (CSA) approved and has an efficiency rating of 99%, so is ideal for those looking for an efficient log set insert. The ceramic logs and the metallic stand itself will help reduce heat loss since the heat will be retained for longer and radiated into the living space as opposed to being lost up a chimney.



This is another charming log set offered by Sure Heat, except this time it’s vented, so if you have a functioning chimney or venting system this is your best choice on a budget. The log set itself features 6 hand painted ceramic logs that glow when heated, for a truly authentic log fire effect.

This set includes the connection hardware, a u-shaped dual burner, pan, grate, and shale. However, be aware that this log set log set does not include the gas valve, so it will need to be purchased separately.

Selection Of Sizes

The 18-inch set is designed with small fireplaces in mind and so fits those with minimum dimensions of 28″ front width; 15″ Depth and 21″ back width. It is a nice looking set, ideal for those looking for a smaller, yet good looking log set.

Other size options include a larger 24-inch set made to fit all fireplaces with minimum dimensions of 32″ front width; 15″ Depth and 24″ back width. Therefore, it goes without saying that you need to measure your fireplace dimensions before making your order!

Heat Output & Efficiency

Although it doesn’t come with casing or a surround, this log set definitely does the job of adding both style and efficiency to any gas fireplace. The fact is that many individuals prefer the look of a gas log set and that is fine, but you should not expect the same efficiency and financial savings you would gain from a fireplace insert.

Oh and don’t forget that this set requires an open and working flue! If you are looking for a vent free gas log set, then check out the other Sure Heat set above.



Final Thoughts

Ultimately, the gas fireplace insert you choose to keep you and your home warm is both a personal and practical decision that will be based on numerous factors, ranging from aesthetic appeal to the precise heating demands of your property.

Whichever type of gas insert you choose, it’s important to consider whether a vent-free or direct-vent option is best for you and your family. While vent-free models offer convenience and a hassle-free installation, many still feel they aren’t as safe as they ought to be, whatever option you go for, bear in mind that brand reputation and user reviews should not be overlooked.

If you live in a property without a gas supply, then you may also want to consider an electric fireplace, or if you live in a rural location a pellet stove or wood stove may be more appropriate.

Finally, ensure you are choosing a model that offers the latest innovative features, including electric ignition and a fan system to circulate the heat evenly throughout your home. You are sure to find gas fireplace inserts with a low price tag, but this may be a false economy in the long term.

About the Author

Dave Miller is a HVAC technician with over 10 years in the industry. Dave created HeatTalk with the ambition for it to become a resource for individuals looking for answers, whether they be a layman, student or a professional.

17 thoughts on “Best Gas Fireplace Inserts of 2021 – A Comprehensive Guide”

  1. Thanks for this website — I’m learning a lot !
    My new-to-me (older) house has a wood-burning fireplace, bricked in and chimney-vented.
    But I’m not wanting to burn wood.
    Is there some way to install a gas fireplace insert – when there is no natural gas supply lines in my neighborhood — at least none that I know of? I’m in an all-electric neighborhood in Dallas.

  2. I curently have a wood fireplace insert. Can one of the reviewed units be useed inside my insert?

  3. Do you have any recommendations for a direct vent gas fireplace insert to covert an older wood burning fireplace?

  4. Dave,
    Good write up.
    I was hoping to find longevity report as well. We had a gas fireplace installed with new construction . The fire wall or something like that cracked and
    Flame isn’t working properly. Service people said we need a new fire box $1700 to repair and hoping we can still get parts. We had no idea these things have a life span. Crapped out about 10 years with very light use. Big unit 40000 + BTU We thought serving would be only thing we would incurre. Disappointed. 🙁

  5. I have an existing conventional fireplace with a gas starter, I would like to put a insert that will use Ceramic logs and retain some heat in home and vent poisonous gases

  6. Hi Dave
    I’m building a home with two gas fireplaces & one real wood burning fireplace

    My question is: I want a modern rectangle shaped gas with my main room. I want something that will be efficient and put out great heat.
    Do I have to have glass doors or can it be open flame?

  7. Dave, exploring gas fireplace insert to replace a wood burning stove. I’m looking into a Lopi 34 DVL (40,000 BTU MAX) output. Are you familiar with manufacturer and model?

    Is it oversized for 3 heating 3. adjacent rooms (living room, dining room and kitchen) on the main level of a split-level home? Also, at the opposite the fireplace, is a staircase (22 feet away) that leads to the second (bedroom level).

    Also considering Kozy Heat, Chaka 34 IPI (34,000 BTU) model for the same area.

    I’d welcome your thoughts before making the purchase. In either case, it will be installed by the dealer. I can be reached by e-mail (below)

  8. Hi Merry! I wouldn’t think so, but I would advise you speak to a local HVAC for a better answer as they will know far more than me! Being in Dallas though, I’d expect a heat pump to be a more economical option!

  9. Hi Claude! I can’t give you a proper answer without knowing more about your set-up sorry. For instance, is it attached to chimney or pipe? In any case, it’s best to consult a local HVAC who will be able to take a look.

  10. Sorry to hear that Kris! The longevity reports are estimations, but I hear you and will certainly take it into account.

  11. Hi Betsy! Great question. It really all depends what your main priorities are. For instance, if your new home is going to be well-insulated and you live in a moderate climate, then you won’t really feel the difference.

  12. Hi Andy! I can’t really comment on these models, but I would personally opt for the one at 40,000 BTUS as you can always turn it down and control with a thermostat. You may also want to consider a heat exchanger system if you don’t have one installed already.

    In conclusion, it shouldn’t have any issues heating adjacent rooms.

  13. Hi Dave,
    I’ve just started looking for a replacement gas fireplace insert. 2.5 years ago, I bought a 1940’s Craftsman house that we had extensively remodeled so we could age in place. The home already had a gas fireplace with the world’s ugliest surround, but I was afraid to use it because I could smell the gas and I get massive migraines around any Carbon monoxide. Well — the problem of repairing the insert was taken care of last spring, in the dead of night, when I heard a horrific crash — and yes, the #@*! fire insert fell from its moorings and crashed to the fireplace’s cerment floor!
    So, I am assuming with my migraine issues, I would be better off with a vented insert. This may be a truly stupid question, but the house is on a single floor and below is a crawl space. Is it possible to vent down instead of through the attic to the roof?

  14. Dave, I presently have a Hearth NG insert in my brick fireplace. It is model Grand XT, which is approximately, 11 years old. do you know of a newer efficient replacement. Do I have to replace it?? It vents up a chimney pipe. I have a steel insert box, and feel the heat is going out the top of the box. Is the another type of insert box. Thanks in advance

  15. Dave, are you familiar with the Regency brand? They seem to have good features, and reasonable price.
    I am exploring the option of a direct vent, gas insert.. Thanks!

  16. We also are looking into replacing/retrofitting our existing wood burning fire place with an insert. Currently we are looking at a Radiant Heat (Valor) and a Napoleon infrared unit with blower. My question is Which one is more efficient for heat distribution effectiveness and speed? Radiant vs Infrared with a blower, It will be an insert with direct venting. Both sales outlet are coming out for a review of our need and pricing/quotation. Which one/style is more efficient?

  17. I’m trying to discern the best direct vent insert between a Heat n Glow and a Fireplace xtrodinaire brand. Do you have any thoughts or recommendation between these two bands as to safety, reliability and the stability of the manufacturing company along with availability of repair parts. (I’ve been stung by Lennox stopping production of fireplace inserts and not continuing to make available repair parts and requiring me to tear out the Lennox and rebuild the whole wall and cavity.)

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