The Kozy Heat Chaska 25 is the smallest gas fireplace insert in the entire Kozy Heat lineup — engineered specifically for the most compact existing masonry fireplaces where even other compact inserts won't fit. With a fireplace opening requirement of just 25-7/8 inches wide (smaller than any other Kozy Heat insert), 26,000 BTU/hr of clean direct-vent heating, 77.58% efficiency on natural gas, included battery backup for power-outage starting, and lifetime quick-latch ceramic glass, the Chaska 25 fits installations no other Kozy Heat insert can accommodate while still delivering meaningful heat output and the longest-lasting glass technology in the line.

The Absolute Smallest Gas Insert in the Kozy Heat Lineup

The Chaska 25 fits cavities even the Chaska 29 can't accommodate. Many of the smallest pre-1900 home fireplaces, small bedroom or library fireplaces, and certain mobile home installations have openings under 29 inches wide — too small even for the Chaska 29 (the next-smallest option). The Chaska 25 requires just 25-7/8 inches of opening width and 15-1/4 inches of depth, making it the only Kozy Heat insert that fits these ultra-compact installations.

If you've measured your fireplace and found it's just barely too small for the Chaska 29, the Chaska 25 was specifically engineered for this exact scenario.

The Chaska 25 isn't just a smaller version of the Chaska 29 — it has its own purpose-built feature set, including some genuinely impressive technology for an insert at this size class:

26,000 BTU/hr input (Natural Gas) or 25,500 BTU/hr (LP) — substantial heat output for a compact insert, well-matched to smaller rooms
Higher efficiency than the larger Chaska 29 — 77.58% NG / 78.17% LP (Steady State). The Chaska 25 is actually the second-most-efficient insert in the Kozy Heat lineup behind only the premium Chaska 335S.
Battery backup included — the SIT ProFlame 2 electronic ignition system can start without household electricity using battery power. Unique to the Chaska 25 in the lineup.
Lifetime quick-latch ceramic glass — Kozy Heat backs the glass on the Chaska 25 with a lifetime warranty. The quick-latch design also makes annual maintenance significantly easier.
Standard 75 CFM blower (fan kit) — fan kit included, not an upgrade
Refractory brick lining standard — traditional brick interior included with upper hood and lower grill
Log set included — no need to purchase separately
Full-function remote control included — adjusts flame size, fan speed, and on/off operation
Co-linear direct vent (3" combustion air / 3" exhaust) — sealed combustion system runs through the existing chimney
Bedroom AND mobile home approved — same approvals as the Chaska 29
Canada P-4 approved — efficiency rating recognized internationally
Custom Kozy shrouds available — integrate the insert with your existing fireplace surround

Will the Chaska 25 Fit Your Fireplace?

The Chaska 25's compact form factor opens installation possibilities other inserts can't match, but the existing fireplace still needs to meet minimum dimensions. Minimum specifications:

Existing Fireplace Requirement	Minimum
Front opening width	At least 25-7/8" (smallest minimum in the entire Kozy Heat lineup)
Back wall width	At least 20-5/8"
Opening height	At least 17-5/8"
Cavity depth	At least 15-1/4"
Chimney condition	Solid-fuel masonry or factory-built non-combustible chimney in good structural condition; must be able to accept a 3" co-linear vent through the existing flue
Hearth/floor protection	Non-combustible hearth in front of the fireplace per local code requirements
Gas line access	Existing gas line or ability to route a new gas line to the insert location

Specifications

Brand	Kozy Heat
Model	Chaska 25
Product Type	Direct Vent Gas Fireplace Insert (Ultra-Compact)
BTU Input (Natural Gas)	26,000 BTU/hr
BTU Input (Liquid Propane)	25,500 BTU/hr
Steady State Efficiency (NG)	77.58%
Steady State Efficiency (LP)	78.17%
P.4 Efficiency (ENERGUIDE)	~79% (Canada P-4 approved)
Burner Type	Fixed output
Ignition System	SIT ProFlame 2 Electronic Ignition with battery backup
Battery Backup	Included (unique feature in the insert lineup)
Vent Type	Direct Vent (3" Co-linear through existing chimney; 3" combustion air / 3" exhaust)
Vent Termination	Approved for use with ICC Excel DV caps
Fuel Type	Natural Gas or Liquid Propane (specify at order; LP pilot and burner orifices included)
Viewing Area	21-7/8 in. (W) × 12 in. (H) — approximately 263 sq. in.
Glass	Quick-Latch Lifetime Ceramic Glass
Glass Warranty	Lifetime (unique among Kozy Heat inserts)
Log Set	Included
Remote Control	Full-function (flame size, fan speed, on/off) included
Blower	75 CFM fan kit included standard (requires 110V)
Refractory	Refractory brick lining standard (upper hood and lower grill)
Bedroom Approved	Yes (direct vent design)
Mobile Home Approved	Yes
Min Fireplace Front Width	25-7/8 in.
Min Fireplace Back Width	20-5/8 in.
Min Fireplace Height	17-5/8 in.
Min Fireplace Depth	15-1/4 in.
Estimated Heating Area	Up to ~800 sq. ft. (varies by insulation, ceiling height, climate)
Warranty	Kozy Heat Limited Lifetime Warranty
Made In	USA (Hussong Manufacturing, Minnesota)

Available Options & Accessories

The Chaska 25 comes with most features as standard equipment. Decisions during ordering focus on:

Fuel Type — Natural Gas or Liquid Propane (specified at order; LP pilot and burner orifices included)
Screen Front Options — multiple decorative screen styles available
Custom Kozy Shrouds — decorative metal frame that integrates the insert with your existing fireplace surround
Decorative Fronts — exterior trim around the firebox opening. Browse our Fireplace Fronts collection for additional compatible styles.
Vent Kit Components — sized for your specific installation; approved with ICC Excel DV caps
Wall Thermostat — optional upgrade from remote-only control

For configuration assistance — choosing the right screen front and shroud combination — contact us. We do this every day.

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