Harvia M3 SL Wood-Fired Sauna Heater

The Harvia M3 SL Classic Wood-Fired Sauna Heater is designed for sauna owners who prefer to load firewood from outside the sauna room. Its through-the-wall firebox allows the stove to be heated from an adjacent space or outdoors, helping keep the sauna interior clean, uncluttered, and comfortable during use.

Well suited for small to medium-sized saunas, the M3 SL delivers reliable heat in a compact format. A glass furnace door provides a view of the flames, adding warmth and ambiance to the sauna experience, while the door’s opening direction can be reversed to suit different installation layouts. For additional functionality, the stove can be paired with a Harvia pipe-mounted water heater, allowing you to heat water while enjoying your sauna.

Built with durability and ease of installation in mind, the M3 SL reflects Harvia’s focus on practical design. Adjustable legs (available on the 20-series) help ensure a stable setup, even on uneven floors, making installation straightforward and dependable.

Key Features

• Designed for sauna rooms 212–459 ft³ (6–13 m³)

• Through-the-wall firebox for external or adjacent-room loading

• Graphite black finish with stainless steel airflow spoiler

• Glass door for fire visibility and added atmosphere

• Compatible with Harvia pipe model water heater

The Harvia M3 SL offers a traditional wood-fired sauna experience with added convenience—ideal for layouts where external loading is preferred.

Chimney pipe not included. Stones sold separately.

• Model: WKM3SL

• Power Output: 16.5 kW

• Recommended Sauna Room Size: 212–459 ft³ (6–13 m³)

• Stone Capacity: 66 lb (30 kg), Ø 10–15 cm

• Heater Dimensions: 15.4? W × (17? + 8.7?) D × 28? H
  (390 × 430 + 220 × 710 mm)