How Does an Electric Fireplace Insert Work?

On this page (7 sections)

1. What is inside an electric fireplace insert?
2. How does the flame effect work without real fire?
3. How does the heater warm a room?
4. What does an electric fireplace insert need to run?
5. How do you install an electric fireplace insert?
6. How much does it cost to run an electric fireplace insert?
7. Which electric fireplace insert should you pick?

An electric fireplace insert works by plugging into a standard wall outlet: LED lights and a rotating reflector create the flame look, and a separate electric heater blows warm air into the room. It needs no wood, gas, venting or chimney, so the flames and the heat run on their own switches.

That simple setup is why these inserts fit into old fireboxes and new cabinets alike. Below is how each part does its job, what the insert needs from your home, and how to choose one that fits your opening.

What is inside an electric fireplace insert?

A light source, a flame-effect mechanism and a fan-forced heater are the core parts. A small control board ties them together, and a remote or panel runs the settings.

The flame effect comes from LED bulbs bouncing light off a spinning rod covered in reflective foil. The light lands on a screen or the brick-patterned back of the firebox, so the "fire" moves without any fuel.

In the PuraFlame Western Insert that backdrop is a three-sided interior brick wall behind a clean glass front trim.

The heater is separate. A heating element warms the air, and a blower pushes it out through the front grille.

Many units also include a thermostat and an overheat shutoff, like the adjustable thermostat and overheat protection the PuraFlame Western Insert has. A remote control lets you change flame and heat settings from across the room.

Because there is no combustion, the whole unit is a metal and tempered glass box with a powder coated black finish. The PuraFlame Western Insert weighs about 46.7 pounds and arrives with the remote and its two AAA batteries included.

How does the flame effect work without real fire?

LED light and a moving reflector trick the eye into seeing dancing flames. Nothing burns, so there is no smoke, soot or ash to clean, and the glass front stays clear.

Flame brightness usually has several steps. The PuraFlame Western Insert offers 3 flame intensities, and those flames can run with or without heat all year.

Because the light is LED, the glow costs very little to run compared with the heater.

The PuraFlame Western Insert also adds a fire crackling sound for atmosphere. The log look is molded resin sitting on an ember bed, so you get the visual without the mess of a wood fire.

Its resin log stands about 11 13/16 in high on the grate above the ember bed, which is close to the height a real log fire reaches in a hearth.

The duraflame Electric Log Set 400 Sq Ft takes the same idea and aims it at an existing fireplace. Its flames are projected onto the back of your firebox, so the moving light appears to rise from the split oak logs and ember bed.

That projection is why a log set needs a real fireplace opening to look its best, while a full insert brings its own brick-patterned interior with it.

How does the heater warm a room?

The heater warms air with an element and a fan blows it into the room, much like a space heater built into a fireplace frame. Most models offer two power levels.

At 120 volts, a 750W setting is a light warm-up and 1500W gives full output. The PuraFlame Western Insert lists about 4600 BTUs at its higher setting, enough for supplemental heat up to 400 sq ft.

The duraflame Electric Log Set 400 Sq Ft uses an infrared quartz element for the same 400 sq ft coverage.

The heat is directed forward from the grille, so keep furniture and curtains a safe distance from the front. Safety shutoffs turn the unit off if it gets too hot, and both of these models include overheat protection.

Neither unit is built to replace a furnace. PuraFlame says plainly that the insert is not a main heat source, and the 400 sq ft figure describes one room rather than a whole home.

Think of the heater as a way to take the chill off a den, bedroom or basement while the main thermostat stays lower.

What does an electric fireplace insert need to run?

A grounded 120V wall outlet is the main requirement. There is no gas line, flue, vent or chimney work, so installation is mostly about fit and access to power.

Plan the cord route before you slide the unit in. The PuraFlame Western Insert has a 6 ft black cord that exits the right side facing the unit, so the outlet needs to be within reach on that side or routed around the frame.

You also need an opening or cabinet that matches the insert's dimensions. The PuraFlame Western Insert's firebox measures about 32 1/8 in wide by 25 9/16 in high by 7 51/64 in deep, and its flat bottom lets it sit directly on the floor.

Check your opening against our electric fireplace insert size guide before ordering.

Because the unit plugs in rather than hard wires, the outlet has to stay reachable after installation. The insert should be plugged directly into a grounded wall outlet, so keep the cord out of foot traffic.

The PuraFlame unit cannot be hard wired, so do not plan on tucking the cord behind finished drywall.

How do you install an electric fireplace insert?

Clear the opening, check the fit, slide the unit in and plug it in. No construction is required for a straightforward swap into an existing firebox.

Remove old logs, grates or debris first. If you are replacing a wood-burning fireplace, block the chimney so drafts and debris don't come down into the opening.

PuraFlame notes that the chimney should be blocked when swapping in an electric unit.

Then slide the insert into the opening and connect the cord. You can also build a surround or cabinet to hold it.

Because it plugs in rather than hard wires, it can come out again for cleaning or moving. Our electric fireplace insert vs gas comparison covers when venting and fuel lines change that plan.

A log set is even simpler. The duraflame Electric Log Set 400 Sq Ft comes fully assembled and ready to use out of the box.

There are no vents to install and no gas lines to run, so you place it in your existing hearth and plug it in. It measures about 20.5 in wide by 12 in high by 8.66 in deep and weighs roughly 12.1 pounds, so one person can set it in place without tools.

How much does it cost to run an electric fireplace insert?

Flames alone cost very little; heat is where the electricity goes. The LED light draws a small fraction of what the heater uses.

A 1500W heater is close to 12.5 amps at 120 volts, and 750W is about half that. At your utility's rate, a full hour at 1500W costs more than an hour with just the flames.

Running it as supplemental heat for short periods keeps the bill predictable.

A plug-in monitor takes the guesswork out. The P3 Kill A Watt Power Monitor measures consumption in kilowatt-hours by day, week, month or year.

Plug the insert into it and you'll see what a cozy evening actually uses. Its four settings let you watch usage over a day, a week, a month or a full year, so you can compare a cold week against a mild one.

The monitor also calculates the cost in dollars for each of those periods once you enter your rate. It is designed for 115 volt AC appliances and handles up to 15 amps, which covers a 1500W insert with room to spare.

A 6.4 ounce unit with a large LCD display, it stays plugged in between the outlet and the fireplace cord.

Which electric fireplace insert should you pick?

Pick the PuraFlame Western Insert for a full firebox look with a remote, or the duraflame log set if you want to drop realistic logs into an existing hearth. Both plug in and both deliver supplemental heat for about 400 sq ft.

The PuraFlame Western Insert measures roughly 35 1/16 in wide overall, with a 32 1/8 in wide firebox, 3 flame intensities, a remote and a 6 ft cord. It suits a masonry opening or a floor-level spot and cannot be hard wired.

The duraflame Electric Log Set 400 Sq Ft is a 20.5 in wide log set at 12 in high. It comes fully assembled and needs only an existing fireplace and an outlet, so it works well when you want the log look without changing the surround.

For a smaller cabinet opening, look at the best 23 inch electric fireplace insert picks. If realistic logs matter most, our roundup of the best electric fireplace insert with logs compares the top models.

Frequently asked questions

How does an electric fireplace insert make flames without fire?

It uses LED lights and a spinning rod with reflective foil to project moving flame shapes onto a screen or the back of the firebox. The effect looks like dancing fire, but there is no combustion, no smoke and no chimney.

Do electric fireplace inserts need venting or a chimney?

No. An electric insert needs only a grounded wall outlet.

You can set one into a masonry opening, a purpose-built cabinet or even against a flat floor, and no flue, gas line or vent is involved.

Can you run the flames without the heater?

Yes on most models. Flame and heat controls are separate, so you can enjoy the glow in summer without adding warmth.

The PuraFlame Western Insert offers 3 flame intensities that work with or without heat.

How much electricity does an electric fireplace insert use?

It depends on the heat setting. A 1500W setting draws roughly 12.5 amps at 120 volts, while 750W draws about half that.

LED flames alone use very little power, and a plug-in monitor can show your exact draw.

Is an electric fireplace insert a main heat source?

Usually not. Most models are built as supplemental heat for one room, such as the 400 sq ft coverage the PuraFlame and duraflame units list.

For whole-home warmth, keep your main heating system running.

Can you hard wire an electric fireplace insert?

Not the plug-in models covered here. The PuraFlame Western Insert runs on a 120V cord and cannot be hard wired.

Check the model's electrical instructions before planning any built-in installation.