Solid fuel boiler with fan-assisted combustion Burnit WBS Active 70 for central heating of premises up to 410m². Constructed for solid fuel burning - wood, wood briquettes class B and coal.
Steel boiler with intelligent electronic controller and electric fan for forced air feed. Solid fuel boilers WBS Active range in nominal output from 20 to 110 kW to satisfy the heating demands of medium to large sized spaces. They are engineered for burning solid fuel - wood, wood briquettes class B and coal, and provide the option for fitting pellet, oil or gas-fired burners.
The boiler body is manufactured from high quality steel with 5mm thickness for the combustion chamber and 3mm thickness for the water mantle. The combustion chamber has a large heat exchanging surface and low chamber impedance. Large firebox door ensures easy loading even of large chunks of wood.
ST–81 temperature regulator is intended for controlling central heating boilers. It controls the water circulation pump, domestic hot water pump and the fan. Four optional modes of the pumps operation: house heating, boiler priority, parallel pumps, summer mode. The controller's casing is designed to be mounted to the boiler installation. Its functions are based on data from sensors. The electronic control unit regulates the burning process with the blower, based on the fuel used and the chimney draught, allowing for a wide range of operation.
To increase the heat exchange, the combustion chamber's surface is ribbed and designed for a three-pass flue gas flow. The mantle completely envelops the firebox for maximized usage of the heat. The boiler's body is insulated from the external conditions by 50mm thick high temperature resisting wool.
For a safe and reliable operation of the boiler, a number of safety devices are installed
- Removable metallic ash grate protects the heat exchanging pipes and the chamber base from the flame
- Pressure relief valve 3 bar incl.in the delivery set
- Safety heat evacuator: a tap-water filled line passes through the uppermost part of the boiler body. In case of overheating it is triggered open by a thermostatic valve (not included) to evacuate the heat off the boiler.
The central heating boiler can operate with natural untreated wood, but also with coal and compressed solid fuel such as briquettes. Maximum length of the wood logs is between 330mm and 500mm depending on the model. Fuel moisture should be 20% or lower.
In order to use the maximum caloricity of the fuel, the wood logs should be dried for a prolonged period of time. High moisture levels reduces caloricity and the output power of the boiler.
This series of boilers is manufactured for burning solid fuel, with the option of adaptation to a different kind of fuel. This is possible by mounting a pellet, gas or an oil burner on the lower door opening. A flange is also needed to mount the burner (optional).
1. Control unit
3. High efficiency thermal insulation
4. Safety heat evacuator
5. Three-pass flue gas flow
7. Combustion chamber
8. Metal ash grate
9. Ash- and- soot container
10. Burner flange (optional)
12. Air feed fan
13. Air intake flap
This appliance complies with EN 303-5.
|Warranty||1 year electronic components, 2 years on the boiler|
|Country of Manufacture||Bulgaria|
|Heat output (kW)||70|
|Approximate heating surface (m²/ft²)||250-410|
|Approximate heating capacity (m³)||1107|
|Dimension Depth (mm)||1225|
|Dimension Width (mm)||730|
|Dimension Height (mm)||1470|
|Loading door size (Height, Width), mm||310/ 490|
|Mantle volume (L)||141|
|Insulation boiler||high efficiency thermal wool|
|Insulation doors||high efficiency thermal wool|
|Combustion chamber volume (L)||120|
|Combustion chamber impedance (Pa/mbar)||41/ 0.41|
|Operating pressure (bar)||3|
|Operating temperature range (°C)||65-85|
|Maximum water temperature (°C)||95|
|Min. return water temperature (°C)||60|
|Recommended fuel||wood, humidity 20%, wood briquettes ; coal|
|Fuel Type||Wood, Briquettes, Coal|
|Maximum length of the firewood logs (mm)||600|
|Required chimney draught (Pa/mbar)||38/ 0.38|
|Flue cleaning opening||O : 150/70 mm|
|Exhaust gas temperature (operation mode), °C||<150|
|Exhaust Location||Back side|
|Flue gas temperature sensor||No|
|Control panel||U: Yes|
|Control unit||ST - 81|
|Control of central heating pump||Yes|
|Electric power supply (V/Hz)||220/ 50|
|Average power consumption (W)||45|
|Combustion forced ventilation||Yes|
|Automatic cleaning system||No|
|Thermostatic draught regulator||No|
|Cold water inlet||A : G 2''/ 135 mm|
|Hot water outlet||B : G 2''/ 1380 mm|
|Distance of hot water outlet||J : 365 mm|
|Height of Hot Water Outlet||B : 1380 mm|
|Safety line sleeve||K : G 3/4'' / 1240 mm|
|Safety heat evacuator inlet/outlet||E : R 1/2'' / 1210 mm|
|Air fan supply||W : 277mm|
|Air intake flap||V : 277 mm|
|Height of Flue Pipe||F: 1055 mm|
|Height of Water Drain Valve||Y : 110 mm|
|Drain||Y : G 1''|
|Burner flange (optional)||Z : 176 mm|
|Ash and soot container||X : Yes|
|Ship Bundle Items||Together|