3
3.3. Fuel
The heater can be heated with dry wood logs with a moisture content below 16%. Moisture content of wood affects the
cleanliness of combustion and heater’s overall efficiency. Different types of wood have different calorific value. You can
start the fire with birch bark, a dry newspaper or specific ignition material (e.g. hexamine fuel tablet).
Do not use the following materials for heating the heater:
- Materials with high combustion temperature (such as chipboard, plastic, coal, briquettes, pellets, etc.);
- painted or impregnated wood;
- waste (such as plastic film, textiles, leather, rubber, disposable diapers);
- garden waste (such as grass, leaves);
- liquid fuels and materials suffused with them.
3.4. Heater stones
The most suitable are the stones with a diameter of 10–15 cm. For heater stones, use only stones that are specifically
provided for this purpose. Before stacking the stones onto the heater they must be cleaned of dust.
Stacking the heater stones:
1. Use the stones, which suite between the steel mesh and heater housing.
2. Place the stones in a uniform layer between the heater housing and the steel mesh so that the entire housing is covered.
Thermal radiation of uncovered heater housing can cause the surrounding objects to heat up to dangerous temperatures, even
beyond the safety distances.
3. Fill the upper part of the mesh and the top of the housing with stones. Do not make a high pile of stones on top of the
heater. After you have placed all the stones, make sure that none of them can roll off the heater.
3.5. Heating the sauna heater
Before heating the heater, make sure that in the sauna or in the safety zone of the heater there are no objects that do
not belong there.
1. Empty the ash drawer.
2. Make sure that the combustion and ventilation air supply is not obstructed.
3. Place the larger logs on the bottom of the fire chamber and smaller ones on top leaving enough space between them for the
combustion air to flow. Use firewood with a diameter of 8-12 cm (at the ignition consider the amount of logs, see Table 1).
LS-heaters
Place the firewood on the rack in the back of the fire chamber. Avoid burning the firewood in the extension part of the
chamber. Do not use too long firewood, even if they fit into the fire chamber (see Figure 5).
Figure 5.
4. It is recommended to pick the first heater-load of firewood (the ignition load) from smaller and easily-igniting pieces of
wood, thus having more air and less weight than the standard load. This is especially important in case of low draft due to
poor weather conditions, in which case the recommended initial load is 1/3 of the norm (Table 1), using 3-5 cm diameter
logs.
Place the ignition material on top of the firewood. Starting the fire on the top part of the wood load produces lower
emissions and combustion is of higher quality.
5. Light the ignition material and close the door. N.B. The heater is not intended for use with the open door. The door can
be opened during ignition, when adding firewood and during combustion products removal. During any other times the door
must be closed. The flow of combustion air is regulated by changing the position of the ash drawer.
N.B. The handles heat up when the heater is heated. For opening the door and ash drawer use the heat protection
cloth included in the supply. For igniting the heater, it is recommended to keep the ash drawer open by up to 40 mm. When
the wood has started to burn, the ash drawer must be placed so that the distance between the ash drawer’s front and the fire
chamber’s wall is 3–10 mm, depending on the actual draft.
- Using too strong draft for heating will cause a risk that the unburned parts can get into the ambient air and cause fire hazard
and environmental pollution, as well as that too intense burning will cause overheating of the heater.
- When the sauna room has been heated up enough and it is time to go to the sauna, you can close the ash drawer to reduce
the intensity of the flame and save firewood.
6. If necessary, when the fire starts to go out, add more firewood with a diameter of 12-15 cm (consider the amount when
adding logs, see Table 1).
N.B. Intensive heating over a long period of time increases the risk of fire.
Excessive heating or overheating (such as several consecutive full loads) can cause the heater and chimney to overheat.
Overheating will shorten the heater’s service life and can cause a fire.
Please note that temperatures over 100 °C in the sauna room may damage the sauna and pose hazard to the sauna user’s
health. If necessary, let your heater, chimney and sauna room cool down.
3.6. Water for generating steam
Please use only clean fresh water for throwing onto the heater. The water must be of sufficient quality because water
containing salt, lime, iron, humus, acidic compounds can cause the heater to rust prematurely. Seawater, in particular, can
lead to corrosion especially quickly.
N.B. Do not throw seawater onto the heater!
Water suitable for throwing onto the heater has:
• humus content of <12 mg/liter;
• the iron content of <0.2 mg/liter;
• calcium content of <100 mg/liter;
• manganese content of <0.05 mg/liter;.