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Harvia

Harvia M3 SL Wood Burning Heater | External Feed | WKM3SL

SKU WKM3SL
$1,416.00
$1,416.00

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SHIPPING & DELIVERY — HARVIA

Most in-stock Harvia heaters, controls, accessories, sauna stones, and other standard products are typically prepared for shipment within approximately 2–7 business days. Availability and timing may vary by product, destination, and fulfillment method.

Once shipped, standard ground delivery for most heaters, controls, stones, and accessories generally takes approximately 3–5 additional business days within the contiguous U.S., depending on destination and carrier routing. Oversized or freight-shipped Harvia products may require additional transit time and delivery coordination.

Harvia sauna cabins and larger specialty products have model-specific lead times. Some models are stocked and ready for fulfillment, while others may require up to approximately 12 weeks. Freight and oversized deliveries may also require additional transit time and delivery coordination.

Once your order is underway, we’ll keep you informed with available shipping and tracking updates. Have a delivery question or working toward a particular project date? We’re happy to help at support@betweenliving.com.

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Product Description

Traditional Sauna Heating with External Feed Convenience and Dual-Room Enjoyment

The Harvia M3 SL WKM3SL wood-burning sauna heater combines authentic sauna performance with the added convenience of an external feed system. Designed for small and medium-sized sauna spaces, this heater allows firewood to be loaded from an adjacent room, creating a cleaner sauna environment while extending the experience beyond the steam room itself.

The external-feed design creates a dual-purpose experience by functioning as both a sauna heater and a fireplace. While the sauna room enjoys rich heat and steam, the adjacent room can benefit from the warm glow visible through the cast-iron framed glass door. Designed and manufactured in Finland, the M3 SL combines traditional sauna atmosphere with practical functionality.

Built for dependable performance and flexible installation, this heater brings warmth and ambiance to multiple spaces.

Key Features

  • External Feed Design: Allows firewood loading from an adjacent room.

  • Dual-Room Heating Experience: Functions as both a sauna heater and fireplace.

  • Wood-Burning Sauna Heater: Provides an authentic traditional sauna atmosphere.

  • Cast-Iron Framed Glass Door: Creates visible fire ambiance in the adjoining space.

  • Designed for Small and Medium Saunas: Delivers balanced heat and steam performance.

  • Floor-Mounted Installation: Stable and practical heater positioning.

  • Upper Connection Opening: Supports flexible chimney installation.

  • Soot Access Opening: Designed for easier maintenance access.

  • Designed and Manufactured in Finland: Built according to Harvia quality standards.

Specifications

Model: WKM3SL
Series: M3 SL
Product Type: Wood-Burning Sauna Heater
Fuel Loading Type: External Feed
Installation Type: Floor Model
Sauna Room Capacity: 212–459 cu. ft.
Stone Capacity Requirement: Minimum 66 lbs
Stone Requirement: 2 Boxes AC3020
Door Type: Cast-Iron Framed Glass Door
Connection Type: Upper Connection Opening
Maintenance Access: Soot Opening
Country of Manufacture: Finland

Specifications

Width: 15.3" (390 mm)
Depth: 25" (640 mm)
Height: 28" (715 mm)

Manufacturer Note: Natural sauna stones vary in shape and size. Additional stones may be recommended for optimal arrangement and performance.

Product Attachments

Data Sheet
User Manual
Additional User Manual
Certificate
Technical Images
Sauna Heater Sizing Calculator
Warranty Information


***REQUIRED (SOLD SEPARATELY)
Stones: AC3020 x 2 boxes
Boxes of stones needed: 2 boxes of 20 kg stones
Accessories:
Protected Shealth Panel WL450 or WL400
Protective Bedding WL100
*Chimney Kit (Silver)
*Chimney Kit (Black)
Check out more pipings that you may need depending on your space or your desired layout

EXPLORE AND COMPARE ALL M3 HEATERS
Fire, stone and the setup around them Have a wood-heater question? Ask away. We can help you understand the product before you build around it.

A wood-burning heater involves more than choosing a stove. Chimney routing, room volume, clearances, stones, protective surfaces and the surrounding sauna design all matter. If one part of the setup is unclear, send us the question before ordering.

You can ask us things like...

Harvia product: Harvia M3 SL Wood Burning Heater | External Feed | WKM3SL
Chimney design, combustion clearances, floor and wall protection, local building requirements and final installation should always be confirmed against the manufacturer documentation and with the appropriate qualified local professional. Between Living can help identify the relevant Harvia specifications and product documents before that conversation.
Your email app will open with the product and your question already prepared. Add room measurements, photos or a sketch of the proposed chimney route if useful, then press send.
Between Living / Harvia

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