30-inch electric fireplace inserts

A 30-inch insert will not fit a 30-inch opening. Model names in this category are series designations rather than measurements — the unit badged 30 inches here actually measures 31 1/8 — and an insert needs an opening wider than the unit, not equal to it. If your opening is 30 inches, you are shopping for a unit around 25 to 27 inches wide, not one called 30.

This is the single most expensive misunderstanding in the category, and it is entirely avoidable. Manufacturers name units by series, by viewing area, or by the opening they are intended for — rarely by the outside dimension that decides whether the thing fits. The four units here illustrate the spread.

Quick picks: the 24 to 33-inch range

Ranked. The running cost column is computed from each unit's rated wattage, not quoted from a manufacturer. Tap a row for the full write-up.

#	Product	Best for	Cost per hour	Price
1	Dimplex Revillusion RBF30 30" Built-In FireboxThe only unit here actually badged 30 inches — and it measures 31 1/8, which is exactly the trap this page is about.	The literal 30-inch, if you are building the opening	27.5¢1,500 W · 5,118 BTU	$1,999.00 · View on Amazon
2	Dimplex Revillusion RLG25 25" Plug-In Log SetAt 25 5/8 inches wide it drops into a 30-inch opening with room to spare — which is usually what someone measuring 30 inches actually needs.	A 30-inch opening you do not want to modify	27.5¢1,500 W · 5,118 BTU	$487.99 · View on Amazon
3	PuraFlame Klaus 33" Electric Fireplace InsertThree inches wider than the Revillusion at 33 1/16, and the one that brings its own glass, mesh and brick lining with it.	A 34-inch opening and up	27.5¢1,500 W · 5,118 BTU	$429.99 · View on Amazon
4	Touchstone Fireplug Pro 33 InsertA 33-inch insert from a company that makes nothing but fireplaces. We earn nothing sending you there, which is why it is on the list.	The brand-direct alternative at the same width	27.5¢1,500 W · 5,118 BTU	$1,099.00 · View on Amazon
—	Duraflame DFI-5010-01 3D Infrared Fireplace StoveTwenty-four inches wide and frequently returned in 30-inch insert searches. It is a freestanding stove — it stands on the floor.Skip this one	Nothing, if you have an opening to fill	27.5¢1,500 W · 5,118 BTU	$259.99 · View on Amazon

#ad Buy links are affiliate links — we earn a commission on Amazon purchases at no extra cost to you, and it never changes the ranking. How this site is funded. Running cost is computed at 18.34¢/kWh; see what these actually cost to run.

Three measurements decide everything, and the one people skip is the one that disqualifies units most often.

1. Width at the front, and again at the back. Masonry openings taper more often than you would expect. The narrower of the two is your real width.
2. Height at the front, and at the back. Same reasoning. Old fireboxes frequently slope inward toward the top.
3. Depth, front to back. The measurement that disqualifies the most units. The RLG25 needs 13 inches; plenty of older fireboxes have less.
4. Then subtract. Take at least an inch off your narrowest width before you start shopping, unless you intend to buy a trim kit to cover the margin.

Nothing about a 30-inch unit makes it less powerful than a 60-inch one. Every full-size unit here is capped at 1,500 W by a 120 V circuit — about 5,118 BTU per hour — regardless of width. A narrower fireplace has a smaller flame, not a smaller heater.

At around 20 BTU per square foot, that is roughly 256 square feet of supplemental heat, which comfortably covers the small and mid-sized rooms that 30-inch openings usually sit in. The room size calculator will do it for your own dimensions.

At this width the decision is mostly about the condition of the masonry. A log set is a tray of logs with a heater behind it, placed inside the opening you already have — the old brick stays visible around it. A full insert brings its own glass, mesh and lining, and finishes the opening for you.

If the firebox is tidy, a log set is cheaper, shallower and looks more like a real fire. If the brick is stained, painted or ragged, a log set puts a good fire inside an unattractive hole and an insert is worth the extra. The longer version of this argument is on log sets vs inserts.