Harvia Legend 240 SL 21 kW Wood-Burning Sauna Stove with Exterior Feed

The Harvia Legend 240 SL is a 21 kW wood-burning sauna stove for rooms of 353–848 cubic feet. It takes 440 lb of 10-15cm sauna stones (sold separately), needs no electrical supply, and requires a code-compliant chimney.

The Legend is Harvia's premium wood-burning line. Its defining feature is a structure that separates combustion air and routes part of it to the top of the fire chamber, so unburned gases ignite instead of going up the flue. The result is a cleaner, hotter, more efficient burn from the same armful of wood.

• Cleaner and efficient burning
• Two-stage combustion — secondary air injection burns off flue gases
• Very large stone mass held in a black steel grate
• Adjustable legs for uneven floors
• Exterior feed: the fire is loaded from an adjoining room or outdoors

These are not included. You need them before the sauna will run.

Harvia lists this model with CE, EAC marks. These are the European and Eurasian conformity marks, not a UL or ETL listing for North America — confirm requirements with your building department and insurer.

The Harvia Legend 240 SL is rated for 353–848 adjusted cubic feet.

Adjusted cubic feet = width × depth × height in feet, plus 45 cu ft for every square foot of glass, tile, concrete or stone, plus 15 cu ft for every square foot of exposed log wall. A 6 × 7 ft room with a 7 ft ceiling is 294 raw cu ft — add a full-glass door and it becomes 834. Always size to the adjusted number.

Work out your room with the sauna heater size calculator

• Confirm the flue diameter and whether your chimney connects top or rear before you order chimney components. This is the most common ordering mistake on wood sauna builds.
• Harvia wood stoves use 115 mm (4.5 in) European flue pipe. A North American 6 in chimney needs the Harvia WZ115155 adapter.
• A solid-fuel appliance usually needs a permit and an inspection in the US, and your insurer will normally want to see the sign-off.
• Burn the stove outdoors or with the room ventilated for the first firing to cure the paint. Load stones loosely by hand and re-stack them once a year.
• This is an LTL freight item. It arrives curbside on a pallet and the carrier calls to book a window — have two people and a pallet jack or dolly ready, and note any damage on the delivery receipt before you sign.
• Stones ship separately on their own freight because of the weight.

Will the Harvia Legend 240 SL connect to a US chimney?

Not directly. Harvia wood stoves are built with 115 mm (4.5 in) European flue pipe, so a North American 6 in system needs the Harvia WZ115155 adapter. Confirm your flue diameter and whether the connection is top or rear before ordering.

Can the Harvia Legend 240 SL be fed from outside the sauna?

Yes — that is what SL means. The fire chamber extension passes through the wall, so wood is loaded from the next room and no smoke, ash or cold air enters the hot room.

How long does the Harvia Legend 240 SL take to heat up?

Harvia does not publish a figure. As a rule of thumb a correctly sized, well-insulated room with a full stone charge is ready 45 to 75 minutes after lighting, and the stones keep giving heat back long after the fire dies down.