Harvia

Harvia Pro 20 Duo Steel 24.1kW Wood Burning Sauna Stove | WKPR20DUOS

Harvia Pro 20 Duo 24.1 kW wood-burning sauna stove, loaded from the next room with the fire in view there, for 283–706 cu ft rooms

$2,871

$3,399

Save $528

Loaded from the next room: firewood and ash stay outside the sauna
Up to 88 lb of 4–6" stones
Wood-fired: no electrical hookup needed

The Sauna Mastery Protocol Digital Guide

$49 FREE

Full-Value Freight Protection

$299 FREE

Perfect for sauna rooms from 283 - 706 ft³

Select Stones

Required for Operation

Harvia Split-Face Olivine Diabase Sauna Heater Stones 4-6" / 44lbs | AC3020 | 2 Boxes
$124

Select Chimney Kit

Required for Operation

Harvia Sauna Stove Chimney Kit | WHP1500 | Stainless Steel
$1,487
Harvia Sauna Stove Chimney Kit | WHP1500 | Black
$1,578

Select Add-Ons

Harvia Protective Bedding SM
$316
Harvia Stainless Steel Water Tank Heater | WP220ST
$727
Harvia Protective Sheath | WL550
$513
Harvia Pipe Adapter | WZ115155
$105
Harvia One-Sided Protective Sheath, 20 Series | WL500
$224

Quantity

Secure checkout
30-day return window*
2-year manufacturer warranty

*Eligible returns must be requested within 30 days of delivery. Restocking and freight charges apply, and some items are final sale. See the Refund Policy.

In stock — estimated delivery in 7–12 days

Curbside freight delivery by appointment; an adult must sign for the shipment.

Description

What is the Harvia Pro 20 Duo wood-burning sauna stove?

The Harvia Pro 20 Duo (WKPR20DUOS) is a 24.1 kW wood-burning sauna stove for sauna rooms of 283 to 706 cu ft, loaded from the next room: its fire chamber passes through the wall and ends in a glass door, so the fire shows in the room outside the sauna. It stands on the floor on adjustable legs, holds up to 88 lb (40 kg) of 4–6" stones on top of a steel body, and connects to the chimney at the top only, through a 4.5" (115 mm) opening. It needs no electrical connection.

The Harvia Pro 20 is the same size stove loaded from inside the sauna, the Harvia Pro 20 SL is the through-the-wall version with a smaller door, and the Harvia Pro 36 Duo is the larger Duo. The Harvia wood-burning stove collection has every Harvia wood-burning stove Topture sells.

Harvia Pro 20 Duo key features

24.1 kW for sauna rooms of 283–706 cu ft (8–20 m³)
Loaded from the next room, with the glass door and fire facing that room
Up to 88 lb (40 kg) of 4–6" stones
Top chimney connection only, 4.5" (115 mm)
Adjustable legs, 0–1.2" (0–30 mm)
Takes firewood up to 15.4" (390 mm) long
CE marked (EN 15821)
2-year manufacturer warranty

Specifications

Does the Harvia Pro 20 Duo fit my sauna?

The Harvia Pro 20 Duo heats sauna rooms of 283 to 706 cu ft (8–20 m³). Harvia's manual adds 1.2 m³ for every square meter of uninsulated brick, glass block, glass, concrete or tile wall, about 3.9 cu ft per sq ft, and a glass door counts: its example is a 10 m³ room with a glass door, which needs the output of a 12 m³ room. Multiply the volume of a solid-log sauna by 1.5. Harvia's data sheet gives a minimum sauna room height of 81.1" (2,060 mm), and the top of the stove needs at least 51.2" (1,300 mm) to the ceiling.

Harvia Pro 20 Duo specifications

Harvia Pro 20 Duo (WKPR20DUOS), Harvia manual Y05-1394-1 09/25 and data sheet WKPR20DUOS
Output	24.1 kW
Sauna room volume	283–706 cu ft (8–20 m³)
Minimum room height	81.1" (2,060 mm)
Dimensions	16.9" W × 31.1" D × 29.9–31.1" H (430 × 510 + 280 mm fire-chamber extension × 760 mm, plus 0–30 mm of leg travel)
Legs	Adjustable, 0–1.2" (0–30 mm)
Net weight	176.4 lb (80 kg)
Stones	Up to 88 lb (40 kg) of 4–6" (10–15 cm) stones; two 44 lb boxes of Harvia AC3020
Chimney connection	Top only, 4.5" (115 mm); chimney class T600 with a flue at least 4.3" (110 mm) across
Wall opening	15.9" (405 mm) wide, 19.1" (485 mm) high; wall at most 4.7" (120 mm) thick
Firewood	Up to 15.4" (390 mm) long, 3.1–5.9" (8–15 cm) across
Materials	Steel body; glass door on the fire-chamber extension
Electrical connection	None; wood-fired
Certification	CE marked (EN 15821)
Harvia part number	WKPR20DUOS (GTIN 6417659036580); versions from 2024
Warranty	2-year manufacturer warranty; stones are not covered

Installation

How is the Harvia Pro 20 Duo installed?

The Harvia Pro 20 Duo stands on a floor strong enough to carry it and its stones, on its adjustable legs, inside the safety distances below, and connects to a T600 chimney. Harvia's manual says all local regulations apply, that the stove is not suitable for a shared flue, and that the local fire authorities can give detailed fire-safety requirements. Harvia's installation manual, under Documents, gives the step-by-step installation and the chimney connection.

What wall opening does the Harvia Pro 20 Duo need?

The Harvia Pro 20 Duo is loaded from the room next to the sauna: its fire-chamber extension passes through an opening in a non-combustible wall, and a flange presses against the wall around the door. Harvia's manual gives the opening as 15.9" (405 mm) wide and 19.1" (485 mm) high, in a wall no thicker than 4.7" (120 mm). The non-combustible wall the stove passes through must reach the roof.

Does the Harvia Pro 20 Duo need floor protection?

It depends on the floor under the Harvia Pro 20 Duo. A bare concrete floor at least 2.4" (60 mm) thick needs no protection. A tile floor needs Harvia protective bedding or similar heat-radiation protection, because the adhesives and waterproofing under tile do not resist the stove's heat. A floor made of combustible material needs the bedding too, plus non-combustible floor protection, at least 17.7" × 31.5" (450 × 800 mm), in front of the stove door on the loading side. Harvia's Pro 20 Duo manual names the WL100 protective bedding for this stove; the Harvia WL100 protective bedding (Protective Bedding SM) is sold separately and does not come with the stove.

Harvia Pro 20 Duo safety distances

Keep at least these distances between the Harvia Pro 20 Duo and anything that can burn.

Harvia Pro 20 Duo minimum safety distances (Harvia manual Y05-1394-1 09/25)
Top of the stove to the ceiling	51.2" (1,300 mm)
Sides to combustible material	11.8" (300 mm)
Rear to combustible material	11.8" (300 mm)
Front to combustible material	11.8" (300 mm)

Harvia Pro 20 Duo with the WL500 or WL550 protective sheath (Harvia manual Y05-0109-1 0925)
Sides	2.4" (62 mm)
Rear	2.4" (62 mm)
Front	16.6" (422 mm)
Sheath to wall	1.2" (30 mm)

The shorter distances apply only with the sheath fitted; without it, use the first table.

Connecting the Harvia Pro 20 Duo to a chimney

The Harvia Pro 20 Duo connects at the top through a 4.5" (115 mm) opening, to a chimney of temperature class T600 with a flue at least 4.3" (110 mm) across; it cannot share a flue with another fireplace. The Harvia WHP1500 chimney kit (sold separately) fits the top opening, and its page gives the roof and clearance requirements. For North American 6" chimney pipe, the Harvia WZ115155 pipe adapter (sold separately) adapts the opening.

What's Included

What's in the box with the Harvia Pro 20 Duo?

Harvia Pro 20 Duo stove body with its stove door and ash box
Flange and fire-chamber extension
Flue pipe connector
Two soot-opening stoppers
Installation and user manual

What you need separately

Two 44 lb boxes (88 lb) of Harvia AC3020 4–6" stones
A chimney: the Harvia WHP1500 chimney kit in stainless steel or black, or a T600 masonry flue
On a tile or combustible floor: the Harvia WL100 protective bedding (Protective Bedding SM), plus non-combustible protection of at least 17.7" × 31.5" in front of the door on the loading side on a combustible floor
Optional: the Harvia WL550 protective sheath or the Harvia WL500 one-sided protective sheath, which shorten the distances to combustible walls
Optional: the Harvia WP220ST water heater, which mounts on the smoke pipe
Optional: the Harvia WZ115155 pipe adapter, for North American 6" chimney pipe

Documents

Harvia Pro 20 Duo, Pro 20 SL and Pro 36 Duo Installation and User Manual

Bathing Brands Harvia Stone Requirements Chart

Warranty

Harvia Warranty

Read the full LIMITED WARRANTY TERMS AND CONDITIONS

Step 1

Size it right

Every heater page lists the exact room size it's rated for, so you can match it to your sauna before you order.

Step 2

Spec your chimney

Through-roof or through-wall, single-wall or insulated, we help you build the right kit for your install.

Step 3

Real löyly

Wood-fired stones make the most authentic löyly — pour water across them and the steam hits the way Finns intended.

WHAT COMES WITH EVERY TOPTURE ORDER

Free Bonuses Included With Your Topture Order

Claim $348 in Free Bonuses Today

BONUS 1

The Sauna Mastery Protocol

The session times, temperatures, and weekly rhythm that turn a sauna into a habit you keep. Covers heat-up protocols and what to expect across your first 30 sessions. Sent to your inbox after purchase.

$49INCLUDED

BONUS 2

Full-Value Freight Protection

Large orders ship fully insured. If freight arrives damaged, Topture helps coordinate the claim and replacement process with the carrier and manufacturer. Proper inspection and damage documentation at delivery are required. Most in-stock orders ship within 2–7 business days.

$299INCLUDED

Retail Price: $3,399

Today's price: $2,871

Choose your options now

We thought about buying a sauna for years and finally did. We absolutely love it, especially in the winter. It’s incredibly easy to assemble with two people the whole family uses it.

Verified buyer

Ordered this sauna fall 2024 and we love it. No better feeling during a Minnesota winter. Lastly, I have to mention the customer service for this purchase has been like no other. Any questions or requests I had were addressed immediately by Topture. I got more than I expected from them and have already recommended them to several people looking for saunas. SO if you're thinking about it, JUST DO IT already..

Verified buyer

Thanks for the great service - greatly appreciated.

Verified buyer

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Installation information

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After the sale

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Same team before and after the sale, from sizing to warranty support.

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Sold by Topture, with the applicable manufacturer warranty.

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Freight damage? We help coordinate the claim and replacement process.

STILL UNSURE?

Frequently Asked Questions

What comes with the Harvia Pro 20 Duo, and what else does it need?

The Harvia Pro 20 Duo ships as the stove body with its door and ash box, its flange and fire-chamber extension, a flue pipe connector, two soot-opening stoppers and Harvia's manual. It needs no electricity, but it does need up to 88 lb (40 kg) of 4–6 in sauna stones, which two 44 lb boxes of Harvia AC3020 cover, a T600 chimney such as Harvia's WHP1500 kit, and, on a tile or combustible floor, Harvia's WL100 protective bedding. None of these come with the stove; Topture sells them, and the WL550 and WL500 sheaths and the WP220ST water heater, separately.

What size sauna does the 24.1 kW Harvia Pro 20 Duo heat?

The Harvia Pro 20 Duo is rated at 24.1 kW and heats sauna rooms of 283 to 706 cu ft (8–20 m³), according to Harvia's manual. Harvia adds 1.2 m³ for every square meter of uninsulated brick, glass, tile or concrete surface, about 3.9 cu ft per sq ft, and counts a glass door: a 10 m³ room with a glass door needs the output of a 12 m³ room. Multiply a solid-log sauna's volume by 1.5. Harvia's data sheet gives a minimum room height of 81.1 in (2,060 mm), with at least 51.2 in (1,300 mm) above the stove. The Pro 36 Duo is the larger Duo.

What wall opening does the Harvia Pro 20 Duo need?

The Harvia Pro 20 Duo needs an opening in a non-combustible wall for its fire-chamber extension, so it is loaded from the room next to the sauna, where its glass door shows the fire. Harvia's manual gives the opening as 15.9 in (405 mm) wide and 19.1 in (485 mm) high, in a wall no thicker than 4.7 in (120 mm), with a flange pressing against the wall. On a combustible floor, non-combustible protection of at least 17.7 by 31.5 in (450 × 800 mm) goes in front of the door.

What chimney does the Harvia Pro 20 Duo need?

The Harvia Pro 20 Duo needs a chimney of temperature class T600 with a flue at least 4.3 in (110 mm) across; it connects at the top only, through a 4.5 in (115 mm) opening, and Harvia's manual does not allow a shared flue. Harvia's WHP1500 steel chimney kit, in stainless or black, joins the top opening with a smoke pipe cut to length; it suits roofs pitched 10° or more (a flat roof needs the WHM24 rain flange) and is CE marked to EN 1856-1. Keep its insulated casing 3.94 in and its uninsulated smoke pipe 19.7 in from anything that can burn. The non-combustible wall the stove passes through must reach the roof.

How is the Harvia Pro 20 Duo installed, and does it need electricity or floor protection?

The Harvia Pro 20 Duo stands on a floor strong enough to carry it and its stones, on adjustable legs, with its fire-chamber extension through the wall, and needs no electrical connection. A bare concrete floor at least 2.4 in (60 mm) thick needs no protection; tile needs Harvia protective bedding because the adhesives and waterproofing under tile do not resist the heat, and a combustible floor needs the bedding plus non-combustible protection in front of the door on the loading side; Harvia's Pro 20 Duo manual names the WL100 bedding. Keep the stove 51.2 in from the ceiling and 11.8 in at the sides, rear and front from combustible material; Harvia's WL500 or WL550 sheath cuts the sides and rear to 2.4 in.

What has to be done before the first fire in a Harvia Pro 20 Duo?

Harvia's manual says to heat the Harvia Pro 20 Duo outdoors first if possible, with the smoke pipes fitted for draught, until the protective paint stops smoking; then let it cool and brush and vacuum off any paint residue. Install the stove, load the stones and heat the sauna to a normal bathing temperature with good ventilation, because the stove may still smoke and smell a little. Once the smoking stops, it is ready for normal use.

What firewood does the Harvia Pro 20 Duo burn, and how hot should the sauna get?

The Harvia Pro 20 Duo takes firewood up to 15.4 in (390 mm) long and 3.1–5.9 in (8–15 cm) across, and Harvia declares loads of about 6.6 lb (3 kg) to light the fire and 9.9 lb (4.5 kg) per refuelling. Empty the ash box before each firing. The stove has no thermostat, so the fire sets the heat: Harvia's rule of thumb is that a sauna over 212°F (100°C) is too hot, and several full loads of wood in a row overheat the sauna, the stove and the chimney and can start a fire.

What problems do Harvia Pro 20 Duo owners run into, and how are they avoided?

Most problems Harvia's manual lists for the Harvia Pro 20 Duo trace back to the chimney, the wood or the stones. Smoke in the sauna or no draught points to a leaking flue connection, a cold flue, an extractor fan pulling air, a full ash box or blocked smoke canals. A sauna that will not heat is usually too big for the stove, has uninsulated walls or is fired with damp wood; stones that stay cool are often smaller than 4 in or broken. A smell on the first firings is the paint curing, and wooden walls darkening over time is normal. Rearrange the stones at least once a year and have the chimney swept regularly.

Who makes the Harvia Pro 20 Duo, and what is it made of?

The Harvia Pro 20 Duo (WKPR20DUOS) is made by Harvia, the Finnish sauna manufacturer. It is a steel stove with a fire-chamber extension that ends in a glass door, and it is CE marked to EN 15821. It measures 16.9 in wide, 31.1 in deep with the extension and 29.9–31.1 in high on its adjustable legs, and Harvia gives its weight as 176.4 lb (80 kg) without stones.

What warranty does the Harvia Pro 20 Duo have?

Harvia's manufacturer warranty covers the Harvia Pro 20 Duo for 2 years of family use. The extra registration year Harvia offers applies to electric heaters only, not to wood-burning stoves, and sauna stones are not covered; the warranty also excludes damage caused by stones Harvia does not recommend. Harvia US Inc. is the warrantor in North America. Topture is an authorized Harvia retailer and assists with troubleshooting and warranty coordination.

How does the Harvia Pro 20 Duo compare with the Pro 20, the Pro 20 SL and the Legend 240 Duo?

The Harvia Pro 20 Duo puts the fire on show in the room next to the sauna, behind a glass door in a wall flange, and heats 283–706 cu ft at 24.1 kW. The Pro 20 is the same output loaded from inside the sauna, and the Pro 20 SL is loaded through the wall with a smaller door. All three hold 88 lb of stones. The Legend 240 Duo is a 21 kW Duo for 353–848 cu ft that holds 440 lb of stones, for a softer, longer-lasting heat.

Where can you buy the Harvia Pro 20 Duo from an authorized dealer?

Topture is an authorized Harvia retailer and sells the Harvia Pro 20 Duo with AC3020 stones, the WHP1500 chimney, WL100 bedding, the WL550 or WL500 sheath and the WP220ST water heater as options. Topture adds Lifetime Expert Support, help with troubleshooting and warranty coordination, free shipping on orders over $200 within the continental US, financing through Shop Pay Installments at checkout, and a 30-day return window.

What does a Harvia Pro 20 Duo cost in total, delivered?

The delivered cost of a Harvia Pro 20 Duo from Topture is the stove price plus the parts it needs: two boxes of AC3020 stones, a chimney such as the WHP1500 kit, and, on a tile or combustible floor, protective bedding. Topture has free shipping on orders over $200 within the continental US, so a Pro 20 Duo order ships free there; Harvia stoves travel on a pallet by freight, with Topture's full-value freight protection. Budget separately for installing the chimney. Compare delivered totals, because some listings price the stove without its stones and chimney. Financing is available through Shop Pay Installments at checkout.

General Topture Questions

Where are you located, and where do you ship from?

Topture is an online retailer serving customers in the contiguous United States. The company is Topture LLC, a Wyoming limited liability company, and its registered business address is 30 N Gould St, Ste N, Sheridan, WY 82801.

Orders ship from manufacturer and distributor warehouses in the U.S. and Canada, and some products ship directly from the manufacturer in Europe. Each product page shows its estimated delivery time.

How much is shipping?

Orders over $200 ship free within the continental United States. Orders under $200 carry a small shipping fee.

Two exceptions: SaunaLife and ThermaSol products carry a freight charge at any order value, and sauna stones ordered without a heater ship at $60 per box because of their weight.

Every charge is shown at checkout before you pay.

Do you provide financing?

Absolutely! To view your financing offer, simply select Shop Pay Installments as your payment method at Step 3 of checkout.

You'll need to enter a debit card to receive your offer, but don’t worry—you can still back out before completing the purchase.

How long will it take for my items to arrive?

If your order is in stock, most orders ship within 2–7 business days of purchase. Transit time then depends on the distance from the warehouse and, for freight, on booking a delivery appointment.

For custom, pre-order or made-to-order items, the estimated delivery time frame is listed on the product page. Delivery dates are estimates, so please don't book installation labor until your order has arrived and been inspected.

What happens after I place my order?

As soon as you place your order, you'll receive a confirmation email with your order details—be sure to keep it for your records. Once your order ships, you'll receive another email with tracking information.

For freight deliveries, the carrier will call or text you to schedule an appointment once the shipment reaches their local terminal. Someone needs to be there to inspect the shipment and sign for it. Smaller parcels arrive by UPS or FedEx without an appointment.

Is there a warranty?

Yes. Products purchased through Topture include the applicable manufacturer’s warranty, subject to the manufacturer’s terms. You’ll find the warranty details for each product under the "Warranty" tab on its product page, and we help with troubleshooting and warranty coordination if an issue comes up.

Do you have a showroom?

We don’t have a showroom — we sell online. Our team is available by phone, email and chat to help you compare models, sizes and heaters, and we can send dimensions, installation manuals and electrical requirements before you buy.

Where do you deliver to?

We deliver throughout the 48 contiguous states, with curbside freight delivery for large items. Free shipping and standard rates apply there only. Alaska, Hawaii, Puerto Rico, other U.S. islands and Canada are quoted separately, depending on the brand and model. We can't ship freight or oversized items to P.O. boxes.

Do you ship internationally?

International Shipping

For many products, yes, including to Canada, by custom quote. Email contact@topture.com with the product and your address before you order; availability and cost depend on the brand and model. Any duties, taxes and customs fees are your responsibility.

Shipping to Hawaii, Alaska, and Puerto Rico

Free shipping applies to the continental United States only. Shipping to Alaska, Hawaii, Puerto Rico and other U.S. islands is quoted separately and depends on the brand and model. Email contact@topture.com for a quote before you order.

Your wood burning sauna heater, done the right way.

Loaded from the next room: firewood and ash stay outside the sauna
Up to 88 lb of 4–6" stones
Wood-fired: no electrical hookup needed

The Sauna Mastery Protocol Digital Guide

$49 FREE

Full-Value Freight Protection

$299 FREE

Secure checkout
30-day return window*
2-year manufacturer warranty

*Eligible returns must be requested within 30 days of delivery. Restocking and freight charges apply, and some items are final sale. See the Refund Policy.

Harvia Pro 20 Duo Steel 24.1kW Wood Burning Sauna Stove | WKPR20DUOS