The most common question we get about electric fireplaces is also the one with the most hand-waving around it online: will it actually heat the room, or is it just a pretty screen? The honest answer is "yes, a room, not a house," and the reason is arithmetic. An electric fireplace is a space heater with a flame display in front of it, and a space heater on a standard American outlet is capped by the circuit it plugs into. This guide does the math, explains what changes when you hardwire a 240 volt unit, and tells you which models we would pick when heat matters and which we would pick when it does not.
The short answer
A plug-in 120 volt electric fireplace tops out around 1,500 watts, which is about 5,100 BTU per hour: enough to warm a closed room of roughly 400 square feet by several degrees, not enough to replace your heating system. Hardwired 240 volt models from Dimplex, Modern Flames and SimpliFire reach 2,500 to 3,000 watts (about 8,500 to 10,000 BTU) and cover 800 to 1,000 square feet. If you need real heat for a large open space, a direct vent gas fireplace at 17,000 BTU and up is the better tool.
Key takeaways
- Every plug-in electric fireplace is capped at about 1,500 watts (roughly 5,100 BTU) because that is what a 120 volt, 15 amp circuit can carry. There is no premium plug-in with a bigger heater.
- 5,100 BTU warms a closed room of about 400 square feet in a house that already has heat. It will not carry an open loft or replace your boiler.
- Hardwiring a dual-voltage unit to 240 volts roughly doubles the output: 8,530 BTU on the Dimplex Ignite Bold, about 10,000 BTU on Modern Flames and SimpliFire.
- Infrared and fan-forced heaters of the same wattage put the same heat into the room. Pick by how you use the space, not by the marketing.
- Plan a dedicated circuit. A 1,500 watt heater draws 12.5 amps, and the manuals say no extension cords or power strips.
- Need real heat in a large space? A compact direct vent gas fireplace starts around 17,000 BTU, more than three times a plug-in electric.
In this guide
- How many BTU does an electric fireplace produce?
- What does 240 volts change?
- Fan-forced ceramic or infrared quartz: does it matter?
- How does the thermostat actually behave?
- What does it cost per hour to run?
- What circuit does it need?
- How do flame-only mode and zone heating work?
- When is a gas fireplace the better heater?
- Our recommended models
- Which should you choose?
- Frequently asked questions
How many BTU does an electric fireplace produce?
Electric resistance heat is 100 percent efficient at the point of use. Every watt that goes into the heater comes out as heat in the room. One watt equals 3.412 BTU per hour, so the conversion is fixed:
| Heater wattage | Heat output | Typical circuit | Manufacturer coverage claim |
|---|---|---|---|
| 750 W (low setting) | About 2,560 BTU/hr | 120 V, 15 A | Takes the chill off a bedroom |
| 1,500 W (every plug-in unit's max) | About 5,100 BTU/hr | 120 V, 15 A, 12.5 amps drawn | Up to 400 to 450 sq ft (Amantii, Modern Flames); Dimplex claims up to 1,000 sq ft with its Comfort$aver system |
| 2,500 W (Dimplex Ignite Bold at 240 V) | 8,530 BTU/hr | 240 V hardwired, 10.4 amps | Up to 1,000 sq ft |
| 2,930 to 3,000 W (Modern Flames, SimpliFire at 240 V) | About 10,000 BTU/hr | 240 V hardwired, 20 A two-pole breaker | Up to 800 sq ft (Modern Flames) |
Why is every plug-in unit 1,500 watts? Because a 120 volt household circuit is 15 amps, and 1,500 watts draws 12.5 amps, which is right at the practical limit of that circuit. There is no premium 120 volt fireplace with a bigger heater. Dimplex, Amantii, Modern Flames, Napoleon, SimpliFire: all 1,500 watts, give or take 40, on a standard plug.
What does 5,100 BTU feel like? In a closed 12 by 15 foot bedroom with the door shut, it will raise the temperature noticeably within twenty minutes and hold it. In a 600 square foot open living and dining area in a drafty prewar building, you will feel warmth within a few feet of the unit and not much else. The coverage figures in the table are manufacturer numbers for an insulated room with the door closed, and they assume the fireplace is topping up a heated house, not fighting a January night on its own. SimpliFire's own manual puts it plainly: the Inception is "not intended for use as a primary heat source."
What does 240 volts change?
Doubling the voltage lets the same wire carry twice the power. A growing number of built-in units ship with a dual-voltage heater that an electrician hardwires to either a 120 volt or a 240 volt circuit, and the heater output changes accordingly:
- Dimplex IgniteXL Bold: 1,500 W and 5,000 BTU at 120 V; 2,500 W and 8,530 BTU at 240 V. Rated for up to 1,000 sq ft.
- Modern Flames Landscape Pro Multi: 1,465 W and 5,000 BTU at 120 V; 2,930 W and 10,000 BTU at 240 V. Modern Flames lists 400 sq ft and 800 sq ft respectively.
- SimpliFire Inception 36: 1,500 W and 5,000 BTU at 120 V; 3,000 W and 10,000 BTU at 240 V.
- Dimplex Optimyst Linear 66 (a water vapor unit): 1,480 W and 5,050 BTU at 120 V; 2,180 W and 7,438 BTU at 240 V.
Ten thousand BTU is a different experience. It is roughly the output of a small gas log set, and it is enough to carry a 700 to 800 square foot apartment living room through a cold evening without the radiators clanking. The catch is the wiring: a 240 volt run means a two-pole breaker in the panel and a dedicated cable to the fireplace location. In a house that is a half-day job for an electrician. In a co-op with a crowded panel it may be the thing that decides the whole project, so we ask about the panel on the first call.
Fan-forced ceramic or infrared quartz: does it matter?
Two heater designs show up in electric fireplaces, and the marketing around them is louder than the difference.
Fan-forced ceramic is what nearly every built-in and linear unit uses: a PTC ceramic element with a blower that pushes warm air out a vent at the top or bottom of the firebox. It warms the air in the room, so it works best with the door closed and takes a few minutes to be felt. Dimplex's Comfort$aver version modulates both fan speed and wattage against the thermostat rather than cycling fully on and off; Dimplex claims about 11 percent less energy than a quartz heater for the same comfort.
Infrared quartz elements radiate heat to the surfaces and people in front of the unit, the way sun through a window does. You feel it almost instantly if you are sitting in line with the fireplace, and it does not dry the air or depend on the door being shut. It is common in freestanding media consoles and some log set inserts.
Here is the part the marketing skips: both are capped at 1,500 watts on a plug. An infrared heater and a ceramic heater of the same wattage put the same total heat into the room. Infrared feels warmer faster at close range; fan-forced warms the whole room more evenly. Pick by how you use the space, not by the BTU claim, because the BTU claim is the same.
From our install team
Check where the heat vent is before you design the wall. Most linear units blow out the top of the glass, the Dimplex Pro Box vents at the top, and the Revillusion log set vents at the bottom. A top vent blowing up into a mantel or a recessed TV cavity is a common reason a TV above a fireplace runs hot. Keep the required clearance, or choose a bottom-vent unit for a TV wall.
How does the thermostat actually behave?
Nearly every unit we sell has a thermostat, but they do not all behave the way a wall thermostat does, and the details matter if you plan to leave the fireplace on while you sleep.
- SimpliFire Inception: set point range of 43 to 99 degrees F. The heater turns off when the room reaches the set point and back on when it drops below it. The temperature sensor is in the remote, so where you leave the remote is where it measures. The heater also shuts itself off after 3 hours of continuous operation.
- Dimplex Comfort$aver (Ignite Bold, Optimyst Linear, Revillusion): rather than cycling, it ramps fan speed and wattage down as the room approaches the target. On the Optimyst Linear the set point range is 59 to 86 degrees F, Eco mode narrows the wattage range, Heat Boost runs full output for 5, 10 or 15 minutes, and frost protection holds 45 degrees F; the Ignite Bold's boost runs up to 20 minutes.
- Modern Flames: two heat settings (high and low) from the panel or remote; the thermostat lives in the Wi-Fi app and turns the heater on whenever the room falls below the set point. Modern Flames notes the thermostat setting does not save when the unit is turned off, so you set it again each session.
The practical takeaway: an electric fireplace thermostat is a comfort control, not a precision instrument. For a bedroom, set it a couple of degrees above where you want to wake up and let it cycle. For a living room you are sitting in, most people just run it on high for the first half hour and drop to low.
What does it cost per hour to run?
Cost is wattage times hours times your electric rate. A 1,500 watt heater uses 1.5 kilowatt-hours per hour; a 3,000 watt 240 volt heater uses 3. The U.S. Energy Information Administration's 2024 state figures put New York's average retail price near 20 cents per kilowatt-hour across all sectors, New Jersey around 16 cents and Florida around 12.5 cents, and residential bills in the city and on Long Island generally land above the state blend once delivery charges are added. Rather than guess your rate, read it off your bill and use the table:
| Your rate per kWh | Flame only (about 15 to 50 W) | 750 W low heat | 1,500 W high heat | 3,000 W at 240 V |
|---|---|---|---|---|
| 15 cents | Under 1 cent | 11 cents | 23 cents | 45 cents |
| 25 cents | About 1 cent | 19 cents | 38 cents | 75 cents |
| 35 cents | About 2 cents | 26 cents | 53 cents | About a dollar |
Two things jump out. The flame costs essentially nothing: Modern Flames rates the Landscape Pro Multi at 15 watts with the heater off, about the same as an LED bulb. And a thermostat-controlled heater does not run at full wattage all evening; once the room is warm it cycles or throttles, so the real hourly figure for a 1,500 watt unit over a four hour evening is usually well under the high-heat column.
What circuit does it need?
This is where plug-in convenience gets oversold. The manuals are specific, and we follow them:
- A 1,500 watt heater draws 12.5 amps. On a 15 amp circuit that leaves almost nothing for anything else, which is why Dimplex's Optimyst Linear manual says a dedicated, properly fused 15 amp circuit is recommended, SimpliFire says a dedicated circuit is "not required, but is recommended to prevent circuit breaker trips," and Modern Flames flatly requires a dedicated 20 amp or higher breaker.
- For 240 volt operation, Modern Flames and SimpliFire both call for a 20 amp two-pole breaker; SimpliFire specifies 12 AWG copper for 240 V and 14 AWG for 120 V.
- No extension cords and no power strips. Modern Flames: "Never use with an extension cord or relocatable power tap." A 12.5 amp continuous load through a cheap cord is a fire risk, full stop.
- Bathroom installs need a GFCI-protected circuit, and anything built into a wall should be wired by a licensed electrician. In New York City that is also what the Department of Buildings and your co-op board will expect to see.
If the only outlet near your fireplace wall shares a circuit with the TV, the sound system and a lamp, the fireplace will trip the breaker the first cold night. Plan a dedicated run from the panel while the wall is open. It is a modest cost on a built-in job and it is the difference between a fireplace you use and one you stop turning the heat on.
Not sure what fits your space? Tell us the room size, whether the door closes, and what your panel looks like, and we will tell you whether 120 volts will do the job or whether it is worth pulling 240. Book a free design consultation and we will help you narrow it down.
How do flame-only mode and zone heating work?
Every electric fireplace we sell runs the flame with the heater off, and most people use that mode nine months of the year. Dimplex goes a step further and lets the installer hard-disconnect the heater at the wiring stage for a unit that is purely decorative, which is useful in a bedroom in a building with steam heat that already runs hot.
The heater earns its keep in the other three months as a zone heater. The idea is simple: your boiler or furnace heats the whole apartment to 66, and the 1,500 watt fireplace brings the one room you are sitting in up to 71. You are paying to heat 400 square feet instead of 1,400, and if the fireplace lets you turn the central thermostat down a degree or two, the fireplace can cost less to run than it saves. That is the realistic case for electric fireplace heat: a comfort layer on top of your main system, in the room you actually occupy, with the door closed.
It is also the right frame for wall-mounted and linear electric fireplaces in a studio or one-bedroom. A 50 or 60 inch linear on the wall opposite the sofa, on its own circuit, will keep a 350 square foot studio comfortable on all but the coldest nights, and the flame runs on pennies the rest of the year.
When is a gas fireplace the better heater?
If the goal is to heat a large or open space, or a room with high ceilings, or to keep a house warm during a power outage, electric is the wrong tool and we will tell you so. A compact Superior DRT2035 direct vent gas fireplace is rated at 17,000 BTU, more than three times a plug-in electric and well above the best 240 volt unit, and larger direct vent gas fireplaces go considerably higher. Gas also radiates through the glass, with an optional blower, so it is felt across the room, not just at the vent. Electronic ignition models with battery backup keep running when the grid does not.
The trade-offs are what you would expect. Gas needs a gas line, a sealed vent to the outdoors, a licensed plumber and, in New York City, a Department of Buildings filing. Direct vent is the only gas option in the five boroughs: vent-free gas fireplaces are legal in much of the country and we sell them, but they cannot be installed in NYC under the NYC Fuel Gas Code, and no new wood-burning fireplaces have been permitted since Local Law 38 of 2015. So the real decision tree for a city buyer is direct vent gas if the wall can take a vent and the heat matters, electric if it cannot or the heat is secondary.
Our recommended models
We split these by what you are buying the fireplace to do. The first group earns its keep as a heater; the second is for the look, with the heater as a bonus. The last card is gas, because sometimes that is the right answer.
Best for heat
Also in this group: the Dimplex Optimyst Linear 66 pairs a true three-dimensional mist flame with a 240 volt capable heater (7,438 BTU), and our water vapor fireplace buying guide covers the water and maintenance side. Browse more in traditional electric fireplaces and electric log sets.
Best for looks, heat optional
See everything side by side in built-in electric fireplaces.
All electric fireplacesBuilt-inLinearWall mountedTraditionalDirect vent gas
Which should you choose?
Choose a 120 volt plug-in or hardwired unit if:
- The room is under about 450 square feet and has a door you can close.
- The building already heats the apartment and you want a comfort layer, not a furnace.
- You rent, or the wall is closed and a dedicated 15 or 20 amp circuit is the most wiring you can add.
- You will run the flame nine months of the year and the heat on a few cold nights.
Choose a 240 volt dual-voltage unit if:
- The room is 450 to 800 square feet with a closed plan, or you want the fireplace to be the main heat in that room on cold nights.
- The wall is open now and an electrician can pull a two-pole 20 amp circuit from a panel that has room.
- You are choosing between the Ignite Bold, the Landscape Pro Multi, the Inception or the Optimyst Linear anyway, since they all ship dual-voltage.
Choose a direct vent gas fireplace if:
- The space is open plan, over 800 square feet, or has high ceilings.
- You want heat during a power outage.
- You own an exterior wall the vent can go through and can get a DOB permit and a Licensed Master Plumber on the job.
- 17,000 BTU and up is the number that actually matches the room.
Our recommendation: under 450 square feet with a door, buy the electric unit you like the look of and put it on its own circuit; the heat will be fine. Between 450 and 800 square feet, buy a dual-voltage unit and pull 240 volts while the wall is open, because that is the difference between a fireplace that warms the room and one that warms the sofa. Beyond that, or in an open loft, go direct vent gas if the wall allows it, or accept the electric as decoration and let the building heat do the work.
Frequently asked questions
How many square feet will a 1,500 watt electric fireplace heat?
Manufacturers rate 1,500 watt units at roughly 400 to 450 square feet as supplemental heat, meaning an insulated room with the door closed in a house that already has central heat. Dimplex rates its Comfort$aver units higher, up to 1,000 square feet, but the heater is still 1,500 watts. In an open or drafty space, expect to feel it within a few feet of the unit.
Can an electric fireplace be my only heat source?
Not in the Northeast. SimpliFire's manual states its unit is not intended as a primary heat source, and that applies to the category. A 240 volt unit at 10,000 BTU can carry one well-insulated room, but a whole apartment needs the building system or a gas fireplace.
How much does it cost to run an electric fireplace per hour?
Multiply the wattage in kilowatts by your rate. At 25 cents per kilowatt-hour, a 1,500 watt heater on high costs about 38 cents an hour, a 750 watt low setting about 19 cents, and the flame alone about a penny. A thermostat cuts the real figure because the heater cycles once the room is warm.
Does an electric fireplace need its own circuit?
Plan on it. A 1,500 watt heater draws 12.5 amps, most of a 15 amp circuit. Dimplex and SimpliFire recommend a dedicated circuit and Modern Flames requires a dedicated 20 amp breaker. Never run one on an extension cord or power strip.
Is 240 volts worth the extra wiring?
If the room is over 450 square feet or you want the fireplace to be the main heat in that room on cold nights, yes. The same unit goes from about 5,000 BTU to 8,500 or 10,000 BTU, and the electrical work is a dedicated two-pole 20 amp circuit, easiest to add while the wall is open.
Is an electric fireplace cheaper to run than gas?
Per BTU delivered, natural gas is generally cheaper than electric resistance heat, but a 1,500 watt electric heats one room while a gas fireplace heats a bigger area. Used as a zone heater that lets you turn the central thermostat down, an electric fireplace can come out ahead. Used to replace central heat, it will not.
Can I mount a TV above an electric fireplace?
Usually, with care. The heater vents at the top of most linear units, so follow the manufacturer's clearance or choose a unit with a bottom vent. SimpliFire states the Inception 36 has no required TV clearance above it; Dimplex and Modern Flames ask you to respect the TV maker's temperature limits.
Talk to a specialist
Tell us the room, and we will tell you if electric will heat it
We have been designing, selling, installing and servicing fire features and outdoor kitchens for over 30 years across New York City, Long Island, Westchester, New Jersey and South Florida. We coordinate the dedicated 120 or 240 volt circuit, our crews frame and finish the wall, and if the honest answer is a direct vent gas unit, we install those too.
Book a free consultationCall 718-326-4328Showroom: 58-30 Maspeth Ave, Maspeth, Queens.
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Written by the NYC Fireplaces & Outdoor Kitchens team. Last reviewed October 2026. We sell, install and service the products discussed here.
Sources: Dimplex IgniteXL Bold XLF6017-XD spec sheet, Dimplex Optimyst Linear installation guide, Modern Flames Landscape Pro Multi spec sheet and owner's manual, SimpliFire Inception 36 owner's and installation manual, Amantii Panorama Deep installation manual, Superior DRT2000 series specification sheet, U.S. EIA state electricity profiles (2024), 2022 New York City Fuel Gas Code, NYC Local Law 38 of 2015. Specifications change; always confirm with the manufacturer's current installation manual.