Short answer: The Kingsman IDV26, sold as the Capella 26, is a direct vent gas insert that slides into an existing wood-burning fireplace. It is rated up to 30,000 BTU, comes with a blower as standard, and offers five front styles to cover different openings. It is a strong choice if your fireplace opening is at least 28 in. wide and your chimney is at least 12 ft tall. It is not for new construction or a wall with no fireplace.
Specifications at a glance
| Type | Direct vent gas insert for an existing solid-fuel fireplace |
|---|---|
| Maximum input | Up to 30,000 BTU, natural gas or propane |
| Blower | Standard: heat-activated, variable speed |
| Glass | Ceramic |
| Minimum opening, slim fronts | 33 in. W centered (31 in. off-center) x 19 1/2 in. H x 14 1/4 in. D |
| Minimum opening, wide fronts | 28 in. W x 19 1/2 in. H x 14 1/4 in. D |
| Minimum back width | 22 in. |
| Venting | Two 3 in. flex liners up the chimney (co-linear) |
| Chimney height | 12 ft minimum, 40 ft maximum |
| Ignition | Millivolt or ProFlame 2 with remote |
| Certification | ANSI Z21.88 / CSA 2.33; bedroom approved |
Figures from Kingsman installation manual 26IDV-MAN17. The rating plate on your unit is the final word on input.
What it is designed to do
The IDV26 turns a drafty wood fireplace into a sealed gas heater. Combustion air comes down one liner from the chimney top and exhaust goes up the other, so the fire does not use room air. Kingsman approves it for masonry fireplaces and for listed factory-built wood fireplaces, provided the existing fireplace is non-combustible, code-compliant and in good condition.
If you are still deciding whether a conversion makes sense, start with how to convert a wood-burning fireplace to gas.
The heat
Up to 30,000 BTU is a lot for a 26 in. class insert, and unlike many linear fireplaces the blower is included. The fan is heat-activated, so it starts once the firebox is warm, and you set the speed with a variable control. Ceramic glass radiates more heat into the room than tempered glass.
Like every Kingsman direct vent unit, the IDV26 is approved as supplemental heat, not as the primary heat source for the home. For help matching output to a room, see our sizing guide.
Five fronts, and why the choice matters
Every IDV26 needs a Clean View front, and the front you pick determines the minimum opening.
- Slim, Slim Deep and Slim Picture Frame are installed with the gas controls inside the fireplace opening. That needs 33 in. of front width if the insert is centered, or 31 in. if it sits off-center. The Slim Deep has a deeper profile for uneven or protruding masonry.
- Wide and Wide Picture Frame can be installed with the controls moved outside the opening and hidden behind the front. That brings the minimum width down to 28 in.
- Picture Frame versions add a larger surround for bigger or older openings that need more coverage.
As of October 2026, natural gas millivolt units with the split oak log set run from $3,866.99 (Slim) to $4,367.99 (Wide Picture Frame). Our IDV26 measuring guide shows how to take the four measurements that decide which front you need.
Ignition: millivolt or ProFlame 2
Millivolt uses a standing pilot and the on-board rocker switch or a wall switch. It needs no household power to run the flame.
ProFlame 2 lights the pilot on demand and includes a remote with thermostat, flame height and fan speed control. It runs on household power with battery backup for outages; the fan does not run on battery. It adds about $952 to the price. In cold climates, or with a chimney taller than 15 ft, Kingsman recommends leaving the pilot in continuous mode during the heating season so the vent stays warm. More in our ignition comparison.
Chimney, hearth and power requirements
- Chimney: two 3 in. flex liners run from the insert to a termination cap at the top. The vertical run must be between 12 ft and 40 ft, with no more than 2 ft of horizontal offset. A chimney that burned wood must be professionally cleaned first.
- Hearth: the floor under the insert must be non-combustible, with a hearth at least 3/4 in. thick, 12 1/2 in. deep and 31 in. wide.
- Power: the blower plugs into a grounded 120 V outlet, so plan for power at the fireplace.
- Gas: the line can enter from either side. Installation must be done by a qualified gas installer. In Massachusetts that means a plumber or gas fitter licensed by the Commonwealth and a listed T-handle shut-off valve.
What is included, and what is not
Included in each configuration: the insert, your chosen front, the media (split oak log set or glass platform with bronze glass), the blower and the safety screen.
Not included: the vent liner kit and termination. Only Kingsman flex venting or the approved DuraVent kit may be used, and your installer sizes it to your chimney.
Limitations to know before you buy
- It only installs into an existing solid-fuel fireplace. For a new wall you need a zero-clearance unit; see zero-clearance vs insert.
- Short chimneys under 12 ft are outside the approved venting range.
- Shallow fireboxes under 14 1/4 in. deep, or boxes that taper to less than 22 in. at the back, will not take it.
- Fuel type and ignition are set at the factory. Converting later requires a Kingsman kit and a qualified technician.
Who should buy it
A good fit if you have a working masonry or factory-built wood fireplace that meets the minimum opening, you want real supplemental heat with a blower, and you would rather keep the existing fireplace than rebuild the wall.
Look elsewhere if your opening is smaller or larger than this size suits. The Capella line also comes in other widths: browse all gas fireplace inserts.
Frequently asked questions
How many BTUs is the Kingsman IDV26?
Kingsman lists the IDV26 at up to 30,000 BTU for natural gas and propane. The rating plate on the unit shows the exact input for your fuel.
Does the IDV26 come with a blower?
Yes. A heat-activated, variable-speed blower is standard.
Is venting included?
No. The liner kit and termination are sold separately and sized to your chimney.
Can it go in a factory-built (prefab) fireplace?
Yes, if it is a listed solid-fuel fireplace. Kingsman prohibits cutting any sheet-metal parts of the existing fireplace to make the insert fit.
Want us to check the fit? Send your opening width, back width, height and depth and we will confirm the right front before you order. Call 877-879-9191, contact us, or view the IDV26 product page.
Source: Kingsman installation manual 26IDV-MAN17 for the IDV26. Codes vary by jurisdiction. This article does not replace the manufacturer instructions or a licensed installer.