Harvia PRO 20 Pro Series 24.1kW Wood-Burning Sauna Stove
The Harvia PRO 20 is a 24.1kW wood-burning sauna stove for medium-sized rooms from 283 to 706 cubic feet, built for vigorous sauna bathing. The large stone compartment produces hearty, dense steam for high-intensity sauna sessions. The cast-iron framed glass door lets the fire glow through into the sauna room. The graphite black frame with stainless steel construction gives the PRO 20 a sophisticated appearance that suits both traditional and contemporary sauna rooms. No electricity required. Firewood is loaded from inside the sauna. Sauna stones (88 lbs, 2 boxes of AC3020, 10-15 cm) are required and sold separately. Delivery is by scheduled freight on a wooden pallet.
Pro Series - built for vigorous sauna bathing
Harvia describes the PRO 20 as designed for vigorous sauna bathing - a deliberate positioning that distinguishes it from the Legend Series and M3. The Pro Series targets serious home sauna users who want sustained high heat output, hearty steam production, and a stove that performs well under frequent, intense use. The 24.1kW output positions the PRO 20 at the higher end of the medium room range, meaning the stove can bring a 283 cu ft room to temperature quickly and sustain a 706 cu ft room at vigorous bathing temperatures. The large stone compartment - designed to hold 88 lbs of AC3020 - produces steam with the density and duration that vigorous sauna bathing demands. The PRO 20's safety distances are notably compact: 4" from sides, 4" from back, and 12" from front to combustible materials, giving sauna designers maximum flexibility in bench and wall placement within the room.
Cast-iron framed glass door - sophisticated design
The PRO 20's cast-iron framed glass door is a consistent feature across the Pro Series. The cast-iron frame provides the thermal mass and durability that the sustained high temperatures of a 24.1kW wood fire require over years of regular intense use. The glass lets the fire be seen from inside the sauna throughout the session - the visual presence of the fire is a meaningful part of the wood-burning sauna experience. The graphite black exterior with stainless steel components is described by Harvia as a sophisticated design - a contemporary finish that works in modern sauna interiors as well as traditional ones.
Flue options, firewood spec, and North American installation
The PRO 20 supports both top flue and back flue connection - selected during installation based on the chimney routing and room layout. All Harvia wood-burning stoves use a 115mm (4.5") European standard flue outlet; a 6" (155mm) North American adapter is required and sold separately (Harvia WZ115155). Maximum firewood length is 15" (390mm) with a diameter range of 3" to 6" (80-150mm) - standard split firewood dimensions for home sauna use. A licensed or certified chimney professional is strongly recommended for all flue installations. The PRO 20 is compatible with the Harvia WL550 protective shield (sold separately), which is designed specifically for the Pro 20, Pro 20 SL, and Pro 20 Duo variants.
24.1kW wood-burning sauna stove for medium-sized rooms from 283 to 706 cubic feet. Designed for vigorous sauna bathing. Large stone compartment - hearty steam production. Cast-iron framed glass door. Graphite black with stainless steel construction. No electricity required. 88 lbs stones required (2 boxes AC3020 10-15 cm, sold separately). Safety distances: 4" sides, 4" back, 12" front. Top or back flue connection. Max firewood 15" / 3-6" diameter. Flue: 115mm - 6" adapter required for North America (sold separately). Adjustable feet. Ash box included. WL550 protective shield compatible. Pallet delivery - scheduled freight appointment required. 2-year warranty (consumer). CE certified. Made in Finland by Harvia.
24.1 kW 283 to 706 cu ft Designed for vigorous sauna bathing Wood-burning - no electricity required Cast-iron framed glass door Graphite black + stainless steel construction Large stone compartment - hearty steam 88 lbs AC3020 stones required (2 boxes, 10-15 cm) Safety distances: 4" sides, 4" back, 12" front Top or back flue connection Max firewood 15" / 3-6" diameter 115mm flue - 6" adapter required for North America Adjustable feet WL550 protective shield compatible Pallet delivery required 2-year warranty (consumer) CE certified - made in Finland
⚠️ 88 lbs AC3020 stones (2 boxes, 10-15 cm) required - not included. 6" North American flue adapter required - not included. Pallet delivery. Stones and the 6" flue adapter must be purchased separately. An additional box is recommended. This stove ships by scheduled freight on a wooden pallet - a delivery appointment is required. Plan for on-site assistance to move the stove from the pallet delivery point to the installation position. A licensed chimney professional is recommended for all flue installations.
ℹ️ PRO 20 vs PRO 20 SL - interior vs exterior feed. WKPR20M (this listing): standard interior feed - firebox door faces into the sauna room, wood loaded from inside. PRO 20 SL: exterior feed variant - fire chamber extends through the sauna wall, wood loaded from an adjacent room or outdoors. Both share the same 24.1kW output, room range, stone requirement, and specifications. Choose the PRO 20 SL if loading wood without entering the sauna room is required.
Specifications
Performance
| Power output |
24.1 kW |
| Fuel type |
Wood - no electricity required |
| Room volume |
283 to 706 cu ft |
| Stone capacity |
88 lbs (2 boxes AC3020, 10-15 cm) - sold separately |
| Max firewood length |
15" (390mm) |
| Firewood diameter |
3" to 6" (80-150mm) |
Physical
| Width |
16.9" (430mm) |
| Depth |
20" (510mm) |
| Height |
29.9"-31.1" (760-790mm) - adjustable via feet |
| Frame |
Graphite black steel |
| Construction |
Stainless steel |
| Door |
Cast-iron framed glass door |
| Mounting |
Floor-standing with adjustable feet |
| Ash box |
Included |
Safety distances (to combustible materials)
| Front |
12" (300mm) |
| Sides |
4" (100mm) |
| Back |
4" (100mm) |
| Note |
Verify against Safety Sheet document below before finalising bench and wall placement |
Flue and installation
| Flue connection diameter |
115mm (4.5") - standard European |
| Flue connection position |
Top or back - selected during installation |
| North American adapter |
6" (155mm) adapter required - sold separately |
| Firebox access |
From inside the sauna room (standard WKPR20M) |
| Delivery |
Scheduled freight - wooden pallet - appointment required |
Pro Series variants - same platform, different configurations
| PRO 20 WKPR20M (this listing) |
24.1kW | Interior feed | Standard stove only |
| PRO 20 SL |
24.1kW | Exterior feed through wall | Reversible door |
| PRO 20 ES |
24.1kW | Interior feed | Built-in 20L water tank (front) |
| PRO 20 LS |
24.1kW | Interior feed | Built-in 30L water tank (left side) |
| PRO 20 Duo |
24.1kW | Heats two rooms + fireplace |
| All variants |
283-706 cu ft | 88 lbs stones | WL550 shield compatible |
Optional accessories (sold separately)
| North American flue adapter |
Harvia WZ115155 (6" / 155mm) |
| Protective shield |
Harvia WL550 (specific to Pro 20/SL/Duo) |
| Pipe-mounted water heater |
Harvia WL200 or WL300 |
| Flue pipe extensions |
Harvia WZ11520, WZ11550, WZ115100 |
What's included
Harvia PRO 20 wood-burning sauna stove - graphite black with stainless steel construction
Cast-iron framed glass door
Ash box
Adjustable feet
Installation and operation manual
2-year limited warranty (consumer use)
Required (not included): 88 lbs AC3020 sauna stones - 2 boxes, 10-15 cm (an additional box recommended); 6" North American flue adapter (Harvia WZ115155). Optional accessories (sold separately): WL550 protective shield; pipe-mounted water heater (WL200 or WL300); flue pipe components (WZ11520, WZ11550, WZ115100). A licensed chimney professional is recommended for all flue installations.
Why the Harvia PRO 20 stands out
24.1kW for vigorous sauna bathing
The PRO 20 is Harvia's purpose-built high-output stove for serious home sauna use. At 24.1kW for rooms from 283 to 706 cu ft, it brings large rooms to temperature faster than lower-output stoves and sustains vigorous bathing temperatures - above 185°F and approaching 200°F - that smaller stoves in the same room range cannot maintain consistently. For sauna enthusiasts who prefer hot, intense sessions with dense steam, the PRO 20 is sized for the experience.
Large stone compartment - hearty steam
The 88-lb stone capacity produces what Harvia describes as "hearty" steam - the dense, moisture-laden steam that results from a well-heated large stone mass. When water is ladled onto a large heated stone mass, the steam production is more generous and sustained than from smaller stone loads. The PRO 20's stone compartment is engineered to hold and retain heat in the stone mass throughout the vigorous sauna session the stove is designed for.
Tight safety distances - 4" sides and back
The PRO 20's 4" clearance to combustible side and back surfaces and 12" clearance to the front are among the tightest safety distances in the Harvia wood stove lineup. These reduced clearances give sauna designers maximum flexibility in bench placement and room layout within the 283-706 cu ft range - particularly useful in medium-sized sauna rooms where every inch of bench positioning matters. Always verify the specific safety distances in the Safety Sheet document below before finalising construction.
Top or back flue connection
The PRO 20 supports flue connection from either the top of the stove or the back, selected during installation to match the chimney routing and room layout. Top flue connection suits ceiling-exit chimney systems; back flue connection suits wall-exit configurations. The flexibility to choose eliminates the need to plan the sauna room around a fixed flue position - the stove adapts to whichever configuration the specific build requires.
WL550 protective shield compatible
The Harvia WL550 protective shield is the model-specific shield designed for the PRO 20, PRO 20 SL, and PRO 20 Duo variants. It mounts around the stove to further reduce safety distances to combustible materials beyond the stove's standard specifications - providing additional installation flexibility and protecting adjacent wall surfaces in the sauna room. The WL550 is sold separately.
Pro Series platform - multiple configurations
The WKPR20M is the base standard interior-feed model in the Pro 20 platform. The same 24.1kW platform is available in exterior-feed (PRO 20 SL), with built-in 20L front water tank (PRO 20 ES), with built-in 30L left-side water tank (PRO 20 LS), and as a dual-room sauna-plus-fireplace combination (PRO 20 Duo). All share the 283-706 cu ft room range, 88-lb stone requirement, and WL550 shield compatibility. Designed, engineered, and made in Finland by Harvia. We are an authorized Harvia dealer.
About Harvia
Made in Finland - CE Certified - Pro Series
Harvia PRO 20. 24.1kW wood-burning. 283-706 cu ft. Vigorous bathing. Cast-iron glass door.
Harvia is a Finnish sauna and spa company established in 1950. The PRO 20 is Harvia's 24.1kW wood-burning sauna stove for vigorous home sauna use in rooms from 283 to 706 cubic feet - graphite black with stainless steel construction, cast-iron framed glass door, large stone compartment, and tight 4" side/back safety distances. 88 lbs of AC3020 stones (2 boxes) and a 6" North American flue adapter are required and sold separately. Pallet delivery. We are an authorized Harvia dealer.
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24.1kW wood-burning - 283-706 cu ft - designed for vigorous sauna bathing
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Cast-iron framed glass door - graphite black + stainless steel
- Safety distances: 4" sides, 4" back, 12" front
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Top or back flue connection - max firewood 15" / 3-6" diameter
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88 lbs AC3020 stones (2 boxes) required - 6" adapter required - both sold separately
PRO 20 vs Legend 240 SL vs M3 vs Legend 150
Choosing between the Harvia wood stoves at BathingBrands
Four Harvia wood-burning stoves are available at BathingBrands. M3 WKM3: 16.5kW, 212-459 cu ft, 66 lbs stones, compact 15.4"W, interior feed, best-selling classic. Legend 150 WK150LD: 16kW, 212-459 cu ft, 264 lbs stones, 21"W, interior feed, cast-iron glass door, large stone mass. Legend 240 SL WKLE20SLM: 21kW, 353-848 cu ft, 440 lbs stones, exterior feed through wall, reversible cast-iron glass door. PRO 20 WKPR20M (this listing): 24.1kW, 283-706 cu ft, 88 lbs stones, interior feed, graphite black + stainless, tight 4" side clearances, designed for vigorous use. For rooms under 460 cu ft: M3 (compact), Legend 150 (large stone mass), or PRO 20 (vigorous bathing, 24.1kW). For large rooms 353-848 cu ft needing exterior feed: Legend 240 SL. For vigorous bathing in the 283-706 cu ft range with a contemporary stainless steel aesthetic: PRO 20.
Manuals and Documents
Warranty
2-year limited warranty (consumer use)
The Harvia PRO 20 is covered by Harvia's 2-year limited warranty from the date of purchase for consumer use. The warranty covers defects in manufacturing and materials under normal use conditions. The warranty does not cover damage caused by improper installation, use of incorrect stone type or size, operating without the required stone load, failure to follow the installation and operating guidelines in the manual, damage from inadequate chimney maintenance, soot fires, or damage from overfiring. A licensed or certified chimney professional is recommended for all flue installation and regular chimney sweep maintenance. Proof of purchase from an authorized Harvia dealer is required for warranty claims. We are an authorized Harvia dealer.
