Electric fireplace insert, the short answer: an electric fireplace insert is a plug-in firebox that slides into an existing fireplace opening, a mantel surround or a built-in wall recess. To choose one, measure the opening's width, height and depth, pick an insert that is slightly smaller than all three, and check its heat output (most plug-in models top out at 1,500 W, about 5,100 BTU per hour) and flame settings. It plugs into a standard household outlet, needs no venting or gas line, and most install in minutes.
This guide is for homeowners and renters who want the look and warmth of a fire without wood, gas or a chimney sweep. It covers what an electric insert is, how to measure an existing fireplace opening, common electric fireplace insert sizes, heat settings and flame effects, how to install an electric fireplace insert step by step, running costs and safety. For the bigger picture, from TV stands to mantels, start with our electric fireplace guide.
What Is an Electric Fireplace Insert?
An electric fireplace insert is a self-contained electric fireplace built to sit inside an opening rather than stand on its own. It combines an LED flame effect, a fan-forced heater and a glass front in a metal box, and it runs on household power. Because there is no combustion, there are zero emissions, no smoke and no ash, and the unit does not need to be vented.
| Type | Where it goes | Best for |
|---|---|---|
| Electric fireplace insert | Inside an existing fireplace, a mantel surround or a wall recess | Converting a wood burning fireplace, or finishing a mantel or entertainment center |
| Electric log set | On the hearth of an open fireplace, no glass front | Keeping an open-hearth look; usually lower heat |
| Wall mounted electric fireplace | Hung on the wall or recessed into a framed wall | Linear, modern looks; no mantel needed |
| Fireplace TV stand or entertainment center | Freestanding furniture with a built-in firebox | Rooms with no fireplace; adds media storage |
Inserts are the most flexible option. You can put an electric insert in an old masonry fireplace, drop it into a freestanding mantel, or slide it into the firebox cavity of an entertainment center. If you are still deciding between furniture styles, see our electric fireplace TV stand guide and our electric fireplace with mantel guide.
Electric vs Gas or Wood Burning Fireplace Inserts
Traditional fireplaces burn wood, and gas inserts burn natural gas or propane. Both create real flames and real heat, but they need a chimney or vent, professional installation and regular inspection. An electric insert trades the real fire for convenience:
- Installation: plug-in, no gas line, no venting, no construction in most cases.
- Heat: about 5,000 BTUs from a 1,500 W heater, which is supplemental zone heat, not whole-house heat. A gas fireplace typically produces much more.
- Efficiency: electric resistance heat turns nearly all of its electricity into heat in the room, while an open wood burning fireplace loses much of its heat up the chimney.
- Use year round: most electric inserts run the flame without heat, so you can enjoy the ambiance in summer.
- Safety: no sparks, embers or carbon monoxide. The glass front stays cooler than a wood or gas firebox, though it is not always cool to the touch and the heat outlet gets warm.
For renters and homeowners who want a cost effective, low-maintenance fire feature, an electric insert is usually the simplest route. If you want real flames and maximum heat output, gas or wood is the better choice.
Electric Fireplace Insert Sizes
There is no single standard size. Electric fireplace inserts are sold in a range of widths, commonly from about 23 in for compact models up to 30–33 in or more for standard and larger openings, with depths from a slim 6 in to 10 in or more. Every model lists its own body dimensions, so the right size always starts with your opening, not a catalog size.
| Insert class | Typical width | Where it fits |
|---|---|---|
| Compact / 24 inch electric fireplace insert | About 23–24 in | Mantel surrounds, entertainment centers, small masonry openings |
| Standard | About 26–30 in | Many existing masonry fireboxes |
| Large | About 33 in and up | Wide traditional fireplaces; often paired with a trim kit |
Check the model's exact width, height and depth before you buy. Small differences matter: a 24 in insert will not fit a 23.5 in opening, and a deep insert will not fit a shallow surround.
How to Measure Your Fireplace Opening
Measuring is the step that decides whether the insert fits. Use a tape measure and write down every number.
- Width: measure across the front of the fireplace opening. Masonry fireboxes often taper toward the back, so also measure the back wall and use the narrowest point.
- Height: measure from the hearth floor to the top of the opening at the front, and again at the back if the top slopes.
- Depth: measure from the front edge of the opening to the back wall at the shallowest point. Note any damper frame or lintel that hangs down.
- Compare to the insert body: the firebox body has to fit inside the opening. The front face or frame can be slightly larger and cover the edges.
- Plan the gap: a trim kit or surround covers the space between a smaller insert and a larger existing fireplace opening. Check which trim kit sizes the model offers.
- Find power: note where the nearest electrical outlet is and whether the power cord can reach it without strain.
For a new mantel or entertainment center, the firebox cavity size is listed on the product page. Match the insert to those numbers rather than guessing.
Heat Output and Heat Settings
Most plug-in electric fireplace inserts use a 1,500 W heater at most, because that is the practical limit of a standard 120 V household outlet. 1,500 W converts to about 5,100 BTU per hour. Many models also have a low setting around 750 W and an adjustable thermostat that cycles the heater off once the room is warm.
Think of electric fireplace insert heat as zone heat for the room you are in. A common rule of thumb for primary heating is about 10 W per square foot, so a 1,500 W insert takes the chill off a living room or bedroom rather than heating a whole floor. Check the model's rated heating area (sq ft) if the manufacturer lists one, and keep your main heating system for the rest of the house.
Flame Effects and Controls
Modern LED flame technology is what makes today's inserts look convincing. When you compare models, look at:
- Flame colors: classic orange is closest to a real wood fire; many inserts add blue, red and multi-color modes.
- Brightness levels: lower settings look more realistic in a dark room and are easier to watch TV beside.
- Log set or media: a realistic resin log set gives a more authentic appearance than a flat screen of flames.
- Flame without heat: lets you run the fire year round for ambiance.
- Remote, timer and display: a remote control and an auto-off timer are the most useful extras.
No electric flame looks exactly like real flames, but a good insert with a log set and adjustable brightness creates a warm, realistic flame effect in most living rooms.
How to Install an Electric Fireplace Insert
Is it easy to install an electric fireplace insert? In most cases, yes. A plug-in insert is designed for easy installation and usually needs no electrician. The general steps are below; always follow the model's manual, which lists the exact clearances and mounting method.
- Measure and confirm the fit using the steps above.
- Prepare the space. In an existing fireplace, clean out ash and soot. In a new mantel or cabinet, finish assembly first.
- Plan the power path. Route the cord to a wall outlet. Plug the insert directly into the outlet, never into an extension cord or power strip.
- Slide the insert in and center it in the opening.
- Secure it with the brackets or screws supplied, if the manual calls for them.
- Add the trim kit or surround to cover gaps, if needed.
- Test it: run the flame, then the heater on low and high, and check that nothing blocks the heat outlet.
Do you need an electrician? Only if there is no outlet within reach, if you want the outlet hidden inside the fireplace, or if the insert is hardwired. Many manufacturers recommend that a 1,500 W heater not share a circuit with other high-draw appliances, so if your breaker trips, ask an electrician about the circuit.
Putting an Electric Insert in an Existing Fireplace
Can you put an electric fireplace insert in an existing fireplace? Yes, and it is one of the most popular ways to convert a wood burning fireplace you no longer use. A few things to keep in mind:
- Close the damper or block the draft as the insert manufacturer recommends, so warm room air does not escape up the chimney.
- Get the chimney checked if the fireplace was used recently, and make sure there are no live embers or leftover fuel.
- Plan the cord: many existing fireplaces have no outlet inside, so the cord usually runs out the front or side to the nearest wall outlet.
- Use a trim kit to cover the gap between the insert and the masonry for a finished look.
- Keep it reversible: a plug-in insert can come out again if you later want to use the fireplace or sell the house.
If you are planning the whole wall, including where the TV goes, see our living room layout with fireplace and TV guide.
How Much Does It Cost to Run?
Running cost is simple to work out: watts ÷ 1,000 × hours × your electricity rate.
- Heat on high: 1,500 W = 1.5 kWh per hour. At 16 cents per kWh, that is about 24 cents per hour.
- Heat on low: about half that on a 750 W setting.
- Flame only: the LED flame alone uses a small fraction of the heater's power.
Do electric fireplace inserts use a lot of electricity? Not compared with central heating, because you heat only the room you are in. A thermostat setting that cycles the heater off also keeps real costs lower than running on high nonstop.
Safety Tips
- Plug the insert directly into a wall outlet; never use an extension cord or power strip.
- Keep curtains, blankets, furniture and other combustibles away from the front and the heat outlet; follow the clearance distances in the manual.
- Don't block the air intake or the heat outlet.
- Turn the unit off and unplug it before cleaning, and let it cool.
- Supervise children and pets near the glass and the warm air outlet.
- If the insert sits in an entertainment center or mantel, anchor the furniture to the wall as the manual instructs.
Maintenance and Common Problems
Electric inserts need little care, but a few habits keep them working:
- Dust the vents every few months so the heater moves air freely.
- Clean the glass with a soft cloth and a non-abrasive cleaner once the unit is cool.
- Heater shuts off: most inserts have overheat protection; clear the vents and check that nothing blocks the outlet.
- Breaker trips: move to a less loaded circuit or ask an electrician.
- Fan noise or a burning smell at first use: a light smell is common the first few times as dust burns off; if it persists, stop and contact the seller.
Homsee 24-Inch Electric Fireplace Insert and Compatible Surrounds
The Homsee 24-inch Electric Fireplace Insert with 12-Color Flame is a compact electric insert sized for mantel surrounds and entertainment centers.
- Size: 23.6 in W × 23.6 in H × 5.9 in D, or 24.6 in tall including the top mounting bracket; 24.3 lbs. The opening needs to be at least 23.6 in wide, 23.6 in tall and 5.9 in deep.
- Heat: up to 1,500 W on standard 110 V household power, about 5,100 BTU per hour, with high and low heat modes and an adjustable temperature setting.
- Flame: 12 flame colors and 5 brightness levels over a resin log set; the flame runs with or without heat.
- Controls: remote control plus top-panel buttons, a digital display and a 0–8 hour timer.
- Build: tempered glass front in a powder-coated steel housing; metal and glass, black finish.
- Setup: ships in one box and takes about 10 minutes to set up in a compatible surround; 2-year warranty.
Which Homsee surrounds does it fit?
- Relievo Grand Carved Fireplace Mantel: the mantel surround only, with a 24 in wide × 24 in tall × 6 in deep firebox opening sized for this insert. The mantel measures 44.5 in H × 55.1 in W × 11.8 in D.
- Relievo Grand Mantel Fireplace: the same carved mantel sold together with the insert, ready to use.
- White Entertainment Center with Built-In Electric Fireplace and 5-Tier Bookcases and the Traditional Entertainment Center with Built-In Electric Fireplace and Bookshelves: both ship with this insert included, so it doubles as a replacement insert for them.
Browse all fireplaces and mantels, or compare fireplace entertainment centers in our fireplace entertainment center guide.
Electric Fireplace Insert Buying Checklist
- Measure the opening's width, height and depth at the narrowest points.
- Choose an insert body smaller than all three, and a trim kit if there is a gap.
- Confirm a wall outlet within reach of the cord.
- Check heat output (watts/BTU) and heat settings for the room size.
- Compare flame colors, brightness and the log set for realism.
- Look for a remote, timer and thermostat.
- Read the manual's clearance and installation steps before you buy.
Frequently Asked Questions
Are electric fireplace inserts worth it?
For most homes, yes. An electric fireplace insert gives you a realistic flame and supplemental heat with no venting, gas line or chimney cleaning, installs in minutes and costs little to run. If you need strong primary heat or want real flames, gas or wood is the better choice.
Can you put an electric fireplace insert in an existing fireplace?
Yes. Measure the existing fireplace opening, choose an insert that fits inside it, close the damper or block the draft as the manufacturer recommends, route the cord to a wall outlet and finish the gap with a trim kit.
What is the standard size of an electric fireplace insert?
There isn't one standard size. Compact inserts are about 23–24 in wide, standard models about 26–30 in, and large models 33 in and up. Depth ranges from about 6 in to 10 in or more. Always match the insert to your opening's measurements.
How do you measure for a replacement electric fireplace insert?
Measure the opening's width, height and depth at the narrowest and shallowest points, then compare them to the insert body dimensions, not the front frame. If you are replacing an insert in a mantel or entertainment center, check the firebox cavity size listed for that piece.
Do electric fireplace inserts need to be vented?
No. Electric inserts burn no fuel and produce no smoke or fumes, so they need no chimney, flue or vent. You do need to keep the unit's own air intake and heat outlet clear.
Do you need an electrician to install an electric fireplace insert?
Usually not. A plug-in insert only needs a nearby standard outlet. Call an electrician if you want a hidden outlet inside the fireplace, if the model is hardwired, or if the circuit keeps tripping.
Can I plug an electric fireplace into a regular outlet?
Yes. Most plug-in inserts run on a standard 110–120 V household outlet. Plug directly into the wall, not an extension cord or power strip, and avoid sharing the circuit with other high-draw appliances.
Do electric fireplace inserts use a lot of electricity?
On high heat a 1,500 W insert uses 1.5 kWh per hour, about 24 cents per hour at 16 cents per kWh. The low setting uses about half, and the flame alone uses very little.
An electric fireplace insert is the quickest way to add a fire feature to an old fireplace, a new mantel or an entertainment center. For more ways to bring a fireplace into your living room, read our complete electric fireplace guide.