Cozy Heat SW Thru-Wall 18 Sauna Stove (18 kW)
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Cozy Heat Quattro Thru-Wall 18 Sauna Stove Cozy Heat
Cozy Heat Quattro Thru-Wall 18 Sauna Stove Cozy Heat
Cozy Heat Quattro Thru-Wall 18 Sauna Stove Cozy Heat
Cozy Heat Quattro Thru-Wall 18 Sauna Stove Cozy Heat
Cozy Heat Quattro Thru-Wall 18 Sauna Stove Cozy Heat
Cozy Heat Quattro Thru-Wall 18 Sauna Stove Cozy Heat
Cozy Heat Quattro Thru-Wall 18 Sauna Stove Cozy Heat
Cozy Heat Quattro Thru-Wall 18 Sauna Stove Cozy Heat
Cozy Heat Quattro Thru-Wall 18 Sauna Stove Cozy Heat
Cozy Heat Quattro Thru-Wall 18 Sauna Stove Cozy Heat
Cozy Heat Quattro Thru-Wall 18 Sauna Stove Cozy Heat
Cozy Heat

Cozy Heat SW Thru-Wall 18 Sauna Stove (18 kW)

SKU: COZYSWTW18
Sale price$2,884.50 USD Regular price$3,205.00 USD
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Cozy Heat Quattro Thru-Wall 18 Sauna Stove Cozy Heat
Cozy Heat SW Thru-Wall 18 Sauna Stove (18 kW) Sale price$2,884.50 USD Regular price$3,205.00 USD
Description

The Cozy Heat SW Thru-Wall 18 is an 18 kW wood-burning sauna stove for rooms of 317–635 cubic feet. It holds 220 lb of stones (sold separately), needs no electrical supply, and requires a code-compliant chimney. The firebox extends through the sauna wall, so wood is loaded from the room next door.

Hand-crafted in Estonia, where sauna is a tradition. Wood-fired sauna stoves produce a mild and long-lasting heat, and are designed for ladling water over hot stones to create a satisfying steam sauna.

  • Smoke gases are 6x cleaner
  • Stove utilizes 25%-40% less fuel than comparable sauna stoves
  • Boasts minimal safety distances
  • Floor mount thru-wall
What's Included
In the Box
Outer frame of the heater, Chimney pipe, Heater body, Cleaning hatch, Heater door with glass, Ash box, Installation and operation manual
Required to Operate

These are not included. You need them before the sauna will run.

Sauna Stones
220 lb capacity. Cozy Heat specifies split-face or rounded stones: 5 boxes of Cozy Stone (split-face, 44 lb each — 220 lb) or 7 boxes of Cozy Round (rounded, 33 lb each — 231 lb). Never fire the stove empty. Chimney
A listed, code-compliant chimney system, plus floor protection where the manual or local code requires it. Cozy Heat supplies no chimney kit — the file lists Harvia chimney kits for this stove.
Product Specifications
Cozy Heat Part Number COZYSWTW18
Power Output 18 kW
Sauna Room Volume 317–635 cu ft
Stone Capacity 220 lbs
Primary Fuel Wood
Maximum Firewood Length 15.74" (400mm)
Firewood Diameter 3.15" to 4.72" (80mm-120mm)
Flue Connection Top
Color / Finish Black Steel
Material STEEL
Dimensions 28.74" - 31.49"D x 21.65"W x 34.25"H
Weight 236 lbs
Shipping Weight 456 lbs
Installation FLOOR/THRU-WALL
Certification German BIMSCH certificate
Warranty 2 years (limited)
Ships LTL freight, curbside
Made In Estonia

Marks as supplied by Cozy Heat: German BIMSCH certificate. Requirements vary by jurisdiction — confirm with your building department and insurer before you install.

Clearances & Safety Distances

The minimum distance to combustible surfaces, as published by Cozy Heat. Measure before you frame the bench.

To the Sides
9.05" (230mm) Behind
9.05" (230mm) In Front
19.68" (500mm) Minimum Room Height
82" (2096mm)

These are minimums to combustible material, not recommendations. Your installation manual and local code take precedence, and a solid-fuel appliance normally needs a permit and an inspection in the US.

Sizing

The Cozy Heat SW Thru-Wall 18 is rated for 317–635 cubic feet.

Measure width × depth × height in feet. Add extra volume for anything that soaks up heat rather than reflecting it — glass, tile, concrete, stone and exposed log all make a room behave larger than its raw measurement. Size to the larger number.

Model Output Room Volume Stones Loading
SW 12 12 kW 210–423 cu ft 175 lbs Inside the room
SW 18 18 kW 317–635 cu ft 220 lbs Inside the room
SW Thru-Wall 12 12 kW 210–423 cu ft 175 lbs Through the wall
SW Thru-Wall 18 18 kW 317–635 cu ft 220 lbs Through the wall

Work out your room with the sauna heater size calculator

Accessories for This Model

What Cozy Heat lists for this stove. All sold separately.

Chimney Cover
Cozy Heat Chimney Cover SW H500, Cozy Heat Chimney Cover SW H700 Sauna Stones
Cozy Stone, Cozy Round Chimney Kit
Harvia Chimney & Assembly Kit, Barrel, Flat Roof — Cozy Heat supplies no chimney system of its own, so the file lists Harvia
Installation & Use Notes
  • Mount to the clearances published above. They are minimums to combustible material, not recommendations.
  • The firebox extension passes through the sauna wall, so wood is loaded from the next room and no smoke, ash or cold air enters the hot room. The wall opening has to be framed to the manual before the stove goes in.
  • Confirm your flue diameter and that a top connection suits your build before ordering chimney components.
  • A solid-fuel appliance normally needs a permit and an inspection in the US, and your insurer will usually want to see the sign-off.
  • Load stones loosely by hand so air moves between them, and re-stack once a year, replacing any that have cracked.
FAQs

How does the Thru-Wall version work?

The firebox extends through the sauna wall so you load wood from the adjoining room. No smoke, ash or cold air enters the hot room, and you are not stepping over bathers to feed the fire. The wall opening has to be framed to the installation manual before the stove is set.

How many boxes of stones do I need?

The stove holds 220 lb. That is 5 boxes of split-face Cozy Stone at 44 lb, or 7 boxes of rounded Cozy Round at 33 lb. Stones are not included, and Cozy Heat recommends ordering one spare box so you can pick the best-fitting stones.

Is a chimney included?

No. Cozy Heat supplies the stove with its own chimney pipe section, but not a full chimney system. Your supplier file lists Harvia chimney kits for this stove, and they are linked above. A solid-fuel installation normally needs a permit and an inspection.

Downloads

Installation & Operation Manual
Cozy Heat Warranty

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Description

The Cozy Heat SW Thru-Wall 18 is an 18 kW wood-burning sauna stove for rooms of 317–635 cubic feet. It holds 220 lb of stones (sold separately), needs no electrical supply, and requires a code-compliant chimney. The firebox extends through the sauna wall, so wood is loaded from the room next door.

Hand-crafted in Estonia, where sauna is a tradition. Wood-fired sauna stoves produce a mild and long-lasting heat, and are designed for ladling water over hot stones to create a satisfying steam sauna.

  • Smoke gases are 6x cleaner
  • Stove utilizes 25%-40% less fuel than comparable sauna stoves
  • Boasts minimal safety distances
  • Floor mount thru-wall
What's Included
In the Box
Outer frame of the heater, Chimney pipe, Heater body, Cleaning hatch, Heater door with glass, Ash box, Installation and operation manual
Required to Operate

These are not included. You need them before the sauna will run.

Sauna Stones
220 lb capacity. Cozy Heat specifies split-face or rounded stones: 5 boxes of Cozy Stone (split-face, 44 lb each — 220 lb) or 7 boxes of Cozy Round (rounded, 33 lb each — 231 lb). Never fire the stove empty. Chimney
A listed, code-compliant chimney system, plus floor protection where the manual or local code requires it. Cozy Heat supplies no chimney kit — the file lists Harvia chimney kits for this stove.
Product Specifications
Cozy Heat Part Number COZYSWTW18
Power Output 18 kW
Sauna Room Volume 317–635 cu ft
Stone Capacity 220 lbs
Primary Fuel Wood
Maximum Firewood Length 15.74" (400mm)
Firewood Diameter 3.15" to 4.72" (80mm-120mm)
Flue Connection Top
Color / Finish Black Steel
Material STEEL
Dimensions 28.74" - 31.49"D x 21.65"W x 34.25"H
Weight 236 lbs
Shipping Weight 456 lbs
Installation FLOOR/THRU-WALL
Certification German BIMSCH certificate
Warranty 2 years (limited)
Ships LTL freight, curbside
Made In Estonia

Marks as supplied by Cozy Heat: German BIMSCH certificate. Requirements vary by jurisdiction — confirm with your building department and insurer before you install.

Clearances & Safety Distances

The minimum distance to combustible surfaces, as published by Cozy Heat. Measure before you frame the bench.

To the Sides
9.05" (230mm) Behind
9.05" (230mm) In Front
19.68" (500mm) Minimum Room Height
82" (2096mm)

These are minimums to combustible material, not recommendations. Your installation manual and local code take precedence, and a solid-fuel appliance normally needs a permit and an inspection in the US.

Sizing

The Cozy Heat SW Thru-Wall 18 is rated for 317–635 cubic feet.

Measure width × depth × height in feet. Add extra volume for anything that soaks up heat rather than reflecting it — glass, tile, concrete, stone and exposed log all make a room behave larger than its raw measurement. Size to the larger number.

Model Output Room Volume Stones Loading
SW 12 12 kW 210–423 cu ft 175 lbs Inside the room
SW 18 18 kW 317–635 cu ft 220 lbs Inside the room
SW Thru-Wall 12 12 kW 210–423 cu ft 175 lbs Through the wall
SW Thru-Wall 18 18 kW 317–635 cu ft 220 lbs Through the wall

Work out your room with the sauna heater size calculator

Accessories for This Model

What Cozy Heat lists for this stove. All sold separately.

Chimney Cover
Cozy Heat Chimney Cover SW H500, Cozy Heat Chimney Cover SW H700 Sauna Stones
Cozy Stone, Cozy Round Chimney Kit
Harvia Chimney & Assembly Kit, Barrel, Flat Roof — Cozy Heat supplies no chimney system of its own, so the file lists Harvia
Installation & Use Notes
  • Mount to the clearances published above. They are minimums to combustible material, not recommendations.
  • The firebox extension passes through the sauna wall, so wood is loaded from the next room and no smoke, ash or cold air enters the hot room. The wall opening has to be framed to the manual before the stove goes in.
  • Confirm your flue diameter and that a top connection suits your build before ordering chimney components.
  • A solid-fuel appliance normally needs a permit and an inspection in the US, and your insurer will usually want to see the sign-off.
  • Load stones loosely by hand so air moves between them, and re-stack once a year, replacing any that have cracked.
FAQs

How does the Thru-Wall version work?

The firebox extends through the sauna wall so you load wood from the adjoining room. No smoke, ash or cold air enters the hot room, and you are not stepping over bathers to feed the fire. The wall opening has to be framed to the installation manual before the stove is set.

How many boxes of stones do I need?

The stove holds 220 lb. That is 5 boxes of split-face Cozy Stone at 44 lb, or 7 boxes of rounded Cozy Round at 33 lb. Stones are not included, and Cozy Heat recommends ordering one spare box so you can pick the best-fitting stones.

Is a chimney included?

No. Cozy Heat supplies the stove with its own chimney pipe section, but not a full chimney system. Your supplier file lists Harvia chimney kits for this stove, and they are linked above. A solid-fuel installation normally needs a permit and an inspection.

Downloads

Installation & Operation Manual
Cozy Heat Warranty