Sierra Flame INS-FM-30 30-Inch Electric Fireplace Insert, Steel Surround

Turn a Masonry or Metal Fireplace Into an Electric One

The Sierra Flame INS-FM-30 is an electric fireplace insert, made by Amantii, that slides into the firebox of an existing wood-burning fireplace, whether masonry or zero-clearance metal. A black steel surround covers the old opening, so what you see is a framed log fire behind glass. It plugs into an ordinary outlet, and the flame runs with the heater on or off, so the fireplace earns its place all year instead of sitting dark. It is the smaller of the two INS-FM sizes.

Best for Smaller Fireplace Openings and Zone Heating

This size suits a fireplace whose opening is at least 31 3/8 inches wide and 19 7/8 inches tall, the rough opening Amantii's 2021 manual gives for the INS-FM-30. Its steel surround is 38 inches wide by 24 7/8 inches tall and sits against the fireplace face, which is how it hides chipped brick or a dated metal front around an opening that size.

As a heater it is meant for one room. Amantii rates it for zone heating of up to 500 square feet. Treat it as a way to warm the room you use most, not as the house's main heat.

The 34-Inch Model Fits a Wider Fireplace, Same Heater

The Sierra Flame INS-FM-34 is the same insert built larger: a wider and taller firebox, a 42-inch surround, and the same heater and controls. Pick between them by your opening, not by heat. Both sizes put out the same warmth, so the larger one only buys you a bigger fire to look at.

Plug It In, or Have an Electrician Hardwire It

The cord leaves the left side of the insert and plugs into a grounded 120-volt outlet. Amantii's manual recommends a dedicated 15-amp circuit so the heater does not share a breaker with other appliances. Sierra Flame's earlier installation manual allows a code-approved, jacketed outlet inside the fireplace itself, never above the insert, which keeps the cord out of sight.

If you would rather have no cord at all, the unit is hardwire ready: an electrician removes the cord behind a cover plate on the left side and connects household wiring to the junction block. A 24-volt wall thermostat can also be wired in on that side, and that wiring is easiest before the insert goes into the fireplace.

Heat Vents Up Top, and the Flame Runs Without It

There are no grills on the front. Warm air is vented upward out of the top of the overlay, so nothing interrupts the view of the logs. The heater has a low and a high setting plus an auto mode that heats at full power below 72°F, drops to low between 72 and 77°F, and switches off above that.

Turn the heater off and the logs and flame keep going on their own, so the fireplace still works as a centerpiece in warm months. From the remote you can mix yellow, orange and red in the flame and change the canopy light above the logs through 13 colors.

Seal the Damper and Plan the Outlet Before Installing

Close and seal the chimney damper before the insert goes in. Sierra Flame's installation notes recommend it to stop air leaking in, and suggest painting the inside of the old firebox with latex paint so old fireplace odors stay out of the room. Leave at least 1 inch at the sides and back and 3/8 inch above the unit, and use the four leveling legs to get it level.

Two things to know before ordering. This model has no Wi-Fi or app. It runs from the remote or the panel on the unit, and Amantii's manual says not to let a timer, smart plug or other outside device switch the heater on. And if a mantel sits above the fireplace, ask us first. Amantii's current manual does not publish a mantel clearance for this insert, so we confirm it with them for your setup.

Optional accessories: Amantii decorative fire glass in 14 finishes to mix with or replace the sable glass that comes with the insert, and Amantii Ember or Ice media for a different bed under the logs.

WARNING: This product can expose you to chemicals including lead, which is known to the State of California to cause birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov.