10 Best Electric Fireplace Insert For Existing Fireplace 2025 in the United States

The Dimplex Revillusion 36" Built-in Firebox is a solid choice for upgrading an existing fireplace with an electric insert. It fits into standard fireplace openings with its 37-inch width and 12-inch depth, allowing for flexible installation—you can surface mount it or recess it fully for a clean built-in look. Heating-wise, it covers about 440 square feet with up to 2575 watts of power, making it suitable to comfortably warm a medium-sized living room.

A standout feature is the flame effect, which uses a Mirage Flame Panel with partially frosted acrylic to create a realistic, reflection-free flame appearance that adds a cozy ambiance without requiring a real fire. The unit includes a thermostat and remote control, making it easy to adjust heat and flame settings from across the room. Safety is addressed with vent-free operation, which simplifies installation since no external venting is required, though usage guidelines for indoor air quality should still be followed. Energy efficiency is reasonable for an electric heater of this size, though power consumption increases at higher heat settings.

The unit carries a two-year warranty, indicating reliability. At nearly 75 pounds, it is somewhat heavy, so professional installation might be advisable. While the firebox provides good heat, it may not be adequate for larger open-plan spaces. The elegant herringbone design may not suit every decor style. This fireplace insert is ideal for users who want a realistic flame effect and dependable heating for a medium-sized room, along with straightforward installation options and remote comfort control.

The Touchstone Sideline Infinity 60" electric fireplace insert is a versatile and stylish option for upgrading an existing fireplace opening. Its size (60" wide) is suited for larger fireplaces and it offers flexibility in installation with four different display options, including three-sided views, which is great if you want a modern look and multiple viewing angles. The heating power is adequate for small to medium rooms, warming up to about 400 square feet with two heat settings (750W and 1500W), controlled by a thermostat to keep the temperature comfortable.

This model excels in visual customization, offering 60 different flame and ember bed color combinations, plus realistic LED flames behind cool-touch glass. The included log set and crystals add to the fireplace's modern and appealing design. Controls are easy to use with a touchscreen, remote, and even smartphone app via Wi-Fi, compatible with Alexa and Google Home for voice commands, which adds convenience.

On the installation front, it can be plugged in or hardwired, but because it’s quite large (8" deep and over 17" tall), you’ll want to measure your fireplace opening carefully to ensure a proper fit. It’s built for wall-mount setups, so it suits built-in fireplace openings rather than freestanding use. Safety-wise, the cool-touch glass and thermostat prevent overheating, making it safe for most home environments. While it provides supplemental heat, it’s not meant to replace a main heating source. The electric heater is fairly efficient for its size, but running it on high heat for long periods could impact your electricity bill. If you want a fireplace insert that combines good heating with striking flame effects and smart home features, the Touchstone model offers a compelling combination. Just be sure your fireplace dimensions match and you’re comfortable with the installation options before buying.

The LegendFlame Damon 39" Electric Fireplace Insert is a strong option for anyone looking to add cozy ambiance and supplemental heat to a room up to about 400 square feet. Its size (roughly 39" wide by 26" high) fits well in many existing fireplace openings, and it offers flexible installation options including free-standing, wall recess, or standard insert. The flame effect is one of its highlights, featuring a larger, more random flame with four brightness and five speed settings, plus realistic resin logs and mood lighting to create an appealing and adjustable visual experience. It also includes a fire crackling sound to enhance the atmosphere.

The unit has a built-in heater with adjustable thermostat and two power settings (750W and 1500W), which works well as a supplemental heat source but is not intended to replace a primary heating system. Convenience is improved with a remote control for easy adjustments. Safety is supported by CSA certification, and the glass front design makes maintenance easier by avoiding dust and ash buildup. Energy-wise, it uses standard 120V power and is vent-free, meaning it does not require chimney ventilation but also limits heat output.

One limitation is that it cannot be hardwired, so it must be plugged into an outlet. The unit comes with a one-year warranty and positive customer feedback, making it a reliable choice for those wanting a stylish insert with decent heat and customizable flame effects. It may not be sufficient for larger spaces or as a main heat source.