Current English installation and operation manual – COZY 12 and COZY 18
Cozy Heat 12 and 18 installation and operation manual. Cozy Heat current manufacturer site.
Small details become expensive problems once installation begins. We ask the questions early, so a mismatched part, an overlooked requirement or an installation issue gets caught while it is still easy to fix.
Our job does not end when your order ships. We stay available through installation and beyond. If something needs attention, we stay involved, work the problem, and help see it through.
We want you to feel good about choosing Sauna Marketplace long after your first session, and confident recommending us to a friend. That standard guides the advice we give, the products we sell, and the way we take care of our customers.
Sauna and heater customers also receive free shipping on sauna accessories for life.
Planning a sauna, or need help with one you purchased from us? Our founders have built saunas from the crate up and both run saunas at home. New customers and existing Sauna Marketplace sauna and heater owners can Ask a product question.
| Package | 12 kW + Split-Face Stones, 12 kW + Rounded Stones, 18 kW + Split-Face Stones, 18 kW + Rounded Stones |
|---|---|
| Tested Heat Output | COZY 12: 11.5 kW, COZY 18: 10.1 kW |
| Installation | Through-wall |
| Wall Opening | 12 kW: 10.0 in wide x 17.3 in tall from the floor; 18 kW: 12.4 in wide x 18.5 in tall; concrete or brick wall up to 5.9 in thick |
| Heat Source | Wood-burning |
| Mounting | Floor-standing |
| Made in | EstoniaAcross the Gulf of Finland, Estonia has a vibrant and growing sauna industry. They're known for innovative design, modern manufacturing, and premium sauna products at an affordable price. |
| Warranty | 2 years |
| Sauna Room Size | COZY 12: 212 to 424 cu ft · COZY 18: 318 to 636 cu ft |
| Sauna Ceiling Height | At least 72 in floor to ceiling; at least 82.5 in for the COZY 18 |
Cozy Heat 12 and 18 installation and operation manual. Cozy Heat current manufacturer site.
Cozy Heat two-year limited warranty. Current authorized U.S. warranty file.
Choose the round through-wall stove before the finishing details. The O cage stays visible while bark, ash, and refueling move to the adjoining room. Cozy builds it with structural-steel firebox walls about 67% thicker than a typical standard-stove wall and clean welds.
It uses about 25% less wood than comparable heaters and still lights and tends like a familiar wood stove. Select 12 or 18 kW, then the exact stone style and box count. Chimney, wall construction, and required protection remain separate.
Wall opening: 12 kW at least 10.0 in wide x 17.3 in tall from the floor; 18 kW at least 12.4 x 18.5 in. Concrete or brick, 5.9 in thick at most.
Starting at $2,475.00 – $3,280.85Price range: $2,475.00 through $3,280.85
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Choose the round through-wall stove before the finishing details. The O Thru-Wall keeps the cylindrical stone cage in view and moves the loading door through the wall. That is a practical fit when you want a softer silhouette and a sauna floor free of the active woodpile.
The package uses the same Cozy structural-steel firebox walls about 67% thicker than a typical standard-stove wall and clean, precise welds as the heater-only listing. Its three-path combustion uses about 25% less wood than comparable heaters, while the fire still lights, regulates, and refuels like a familiar wood stove.
Every option pairs the exact Cozy Heat O Thru-Wall heater with the package’s current stone-box count. Split-face stones give the cage a rougher, more architectural texture. Rounded stones make the visible field feel softer. Both choices are olivine diabase; the difference shown here is shape and appearance, not a promise that one produces better steam.
On a phone, swipe the table sideways to compare every column.
| Package option | Stone boxes | Manufacturer stone mass |
|---|---|---|
| 12 kW + split-face stones | 5 boxes | 243 lb required by the current model drawing |
| 12 kW + rounded stones | 5 boxes | 243 lb required by the current model drawing |
| 18 kW + split-face stones | 8 boxes | 353 lb required by the current model drawing |
| 18 kW + rounded stones | 8 boxes | 353 lb required by the current model drawing |
The table separates the package box count from the heater’s technical stone load. Stone size and packing change the final weight inside the cage, so follow the exact manual and keep the stove body covered without blocking airflow.
Choose 12 kW for an adjusted 212–424 cu ft room or 18 kW for 318–636 cu ft. Add about 4 cu ft for every square foot of glass, tile, brick, concrete, or other uninsulated surface; multiply a massive-log room by 1.5. The firebox passes through a properly built noncombustible wall opening, so wood and ash can stay in the adjoining room.
Cozy’s manual (section 2.5, Models COZY TW) puts the stove through an opening in a concrete or brick wall no more than 5.9 in thick. The 12 kW needs an opening at least 10.0 in wide and 17.3 in tall measured from the floor; the 18 kW needs at least 12.4 in wide and 18.5 in tall. Combustible material must stay at least 23.7 in from the sides of the opening and 37.8 in above it, and the through-wall extension adds 5.9 in to the stove depth.
The current manual and 24-month limited warranty are in Manuals & Documents. Use them before the room is closed up.
Want us to check the room volume and loading side with you? Call or text (844) 565-1113 before choosing the package option.
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Write a reviewWhat customers say about working with our team. Names are shortened to a first name and last initial, or to initials.
★★★★★“The Ben(s) have been absolutely amazing to work with. From emails, to phone calls, to (late) night texts, they have literally answered every question with care, complete accuracy and honesty. And, sometimes a bit of humor. Seriously, couldn't recommend them and the entire SaunaMarketplace team highly enough if you are in the market for a sauna, a heater or any type of related item.”
★★★★★“It's been a pleasure working with you. Really appreciated your responsiveness and willingness to share your expertise. Top notch customer service!”
★★★★★“Easily the best customer experience I’ve ever had.”
★★★★★“The Ben(s) have been absolutely amazing to work with. From emails, to phone calls, to (late) night texts, they have literally answered every question with care, complete accuracy and honesty. And, sometimes a bit of humor. Seriously, couldn't recommend them and the entire SaunaMarketplace team highly enough if you are in the market for a sauna, a heater or any type of related item.”
★★★★★“It's been a pleasure working with you. Really appreciated your responsiveness and willingness to share your expertise. Top notch customer service!”
★★★★★“Easily the best customer experience I’ve ever had.”
★★★★★“The Ben(s) have been absolutely amazing to work with. From emails, to phone calls, to (late) night texts, they have literally answered every question with care, complete accuracy and honesty. And, sometimes a bit of humor. Seriously, couldn't recommend them and the entire SaunaMarketplace team highly enough if you are in the market for a sauna, a heater or any type of related item.”
★★★★★“It's been a pleasure working with you. Really appreciated your responsiveness and willingness to share your expertise. Top notch customer service!”
★★★★★“Easily the best customer experience I’ve ever had.”
★★★★★“The Ben(s) have been absolutely amazing to work with. From emails, to phone calls, to (late) night texts, they have literally answered every question with care, complete accuracy and honesty. And, sometimes a bit of humor. Seriously, couldn't recommend them and the entire SaunaMarketplace team highly enough if you are in the market for a sauna, a heater or any type of related item.”
★★★★★“It's been a pleasure working with you. Really appreciated your responsiveness and willingness to share your expertise. Top notch customer service!”
★★★★★“Easily the best customer experience I’ve ever had.”
★★★★★“The Ben(s) have been absolutely amazing to work with. From emails, to phone calls, to (late) night texts, they have literally answered every question with care, complete accuracy and honesty. And, sometimes a bit of humor. Seriously, couldn't recommend them and the entire SaunaMarketplace team highly enough if you are in the market for a sauna, a heater or any type of related item.”
★★★★★“It's been a pleasure working with you. Really appreciated your responsiveness and willingness to share your expertise. Top notch customer service!”
★★★★★“Easily the best customer experience I’ve ever had.”
★★★★★“The Ben(s) have been absolutely amazing to work with. From emails, to phone calls, to (late) night texts, they have literally answered every question with care, complete accuracy and honesty. And, sometimes a bit of humor. Seriously, couldn't recommend them and the entire SaunaMarketplace team highly enough if you are in the market for a sauna, a heater or any type of related item.”
★★★★★“It's been a pleasure working with you. Really appreciated your responsiveness and willingness to share your expertise. Top notch customer service!”
★★★★★“Easily the best customer experience I’ve ever had.”
Planning guides: How to choose a Cozy Heat stove · Sauna heater calculator
Small details become expensive problems once installation begins. We ask the questions early, so a mismatched part, an overlooked requirement or an installation issue gets caught while it is still easy to fix.
Our job does not end when your order ships. We stay available through installation and beyond. If something needs attention, we stay involved, work the problem, and help see it through.
We want you to feel good about choosing Sauna Marketplace long after your first session, and confident recommending us to a friend. That standard guides the advice we give, the products we sell, and the way we take care of our customers.
Sauna and heater customers also receive free shipping on sauna accessories for life.
Planning a sauna, or need help with one you purchased from us? Our founders have built saunas from the crate up and both run saunas at home. New customers and existing Sauna Marketplace sauna and heater owners can Ask a product question.
| Package | 12 kW + Split-Face Stones, 12 kW + Rounded Stones, 18 kW + Split-Face Stones, 18 kW + Rounded Stones |
|---|---|
| Tested Heat Output | COZY 12: 11.5 kW, COZY 18: 10.1 kW |
| Installation | Through-wall |
| Wall Opening | 12 kW: 10.0 in wide x 17.3 in tall from the floor; 18 kW: 12.4 in wide x 18.5 in tall; concrete or brick wall up to 5.9 in thick |
| Heat Source | Wood-burning |
| Mounting | Floor-standing |
| Made in | EstoniaAcross the Gulf of Finland, Estonia has a vibrant and growing sauna industry. They're known for innovative design, modern manufacturing, and premium sauna products at an affordable price. |
| Warranty | 2 years |
| Sauna Room Size | COZY 12: 212 to 424 cu ft · COZY 18: 318 to 636 cu ft |
| Sauna Ceiling Height | At least 72 in floor to ceiling; at least 82.5 in for the COZY 18 |
Cozy Heat 12 and 18 installation and operation manual. Cozy Heat current manufacturer site.
Cozy Heat two-year limited warranty. Current authorized U.S. warranty file.
Heaters rated for the same rooms as the Cozy Heat O, side by side. Rows that differ are marked in orange.
Swipe the table to see all 4 →
| Heater | This heaterCozy Heat O | HUUM HIVE Wood | Harvia M3 SLCosts $550 less | Harvia DuoFor rooms up to 1,271 cu ft |
|---|---|---|---|---|
| Price | From $2,187 | From $2,630 | From $1,645 | From $3,112 |
| Price includes | Package with stones | With the stones | With the stones and the 6 in pipe adapter | With the stones and the 6 in pipe adapter |
| Rated for rooms of | 212 to 636 cu ft | 212 to 565 cu ft | 212 to 459 cu ft | 283 to 1,271 cu ft |
| Power | – | 13, 17 kW | 16.5 kW | 24.1, 31 kW |
| Power supply | No circuit needed | No circuit needed | No circuit needed | No circuit needed |
| Start from a phone | No | No | No | No |
| Mounting | Floor | Floor | Floor | Floor |
| Loading the fire | From the next room | Inside the sauna or From the next room | From the next room | From the next room |
| Stones | 198 to 287 lb | 199 to 287 lb | 66 lb | 88 to 132 lb |
| Ceiling height | At least 6 ft | At least 6 ft 5 in | At least 6 ft 7 in | At least 6 ft 9 in |
| Warranty | 2 years | 3 years | 2 years | 2 years |
| Made in | Estonia | Estonia | – | Finland |
| Open | See the HUUM HIVE Wood | See the Harvia M3 SL | See the Harvia Duo |
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