Wood fired fuel boiler 20 to 110kW (biomass) BURNiT WBS 20 to 110kW


1 161,60 € tax incl.


The wood fired boiler WBS is a boiler of 20kW to 110kW which will warm with no problem at all houses of 960ft² in 7000ft². Equipped with a big combustion chamber (logs of 15 to 23in) this is ideal for your central heating. It can adapt itself to a gas burner, to an oil or to granules.

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Fire-wood boiler WBS

The wood fired boiler WBS possesses a big easily accessible combustion chamber for the load, thanks to its frontal main entrance. The exchange of heat is improved by the pans and the passage in 3 ways of gases.

Level safety, the wood-fired boiler WBS has a rein on the lower door for the assembly of the gas burner, the oil or pellets. The shirt with water is equipped with a safety valve 3 bars and the boiler possesses a thermostatic regulator of the edition. Finally, he possesses a technical heat exchanger of protection bound to the installation of food of water, in case of overheating, some cold water will come to lower the temperature.

This model of wood-fired boiler answers the European standards of safety EN 303-5.

Boiler warranty : 2 years

Product Features


  • Simple installation and handling.    
  • The water mantle embraces the combustion chamber in full to utilize the emitted heat most efficiently.
  • Combustion chamber with large heat exchanging surface and low chamber resistance.
  • Large firebox door ensures easy loading even with bigger logs (length of logs up to 50 cm).
  • Ribbed chamber surface and three-pass flue gas flow for improved heat exchange.
  • Exchangeable metallic ash grate protects the pipe grid from the flame.
  • Burner flange on lower door for fitting pellet, oil or gas burners (optional).

Safety devices


  • Thermostatic draught regulator;
  • Pressure relief valve 3 bar;
  • Safety heat evacuator a tap-water-filled line passes through the upmost part of the boiler body. In case of overheating it is triggered open by a thermostatic valve (not included) to evacuate the heat of the boiler. 


Boiler WBS chart


1. Temperature indicator
2. Housing
3. High efficiency thermal insulation
4. Safety heat evacuator
5. Three-pass flue gas flow
6. Water mantle (jacket)
7. Combustion chamber
8. Metal grate
9. Ash-and-soot container
10. Burner flange
11. Flue
12. Hot water outlet
13. Thermostatic regulator
14. Air intake flap

Тechnical specifications


Chart boiler WBS



Nominal heat outputkW20253040506090110
Height Hmm11451145114511451145128512851285
Width L x Depth Dmm464 x 870464 x 930524 x 930624 x 930624 x 990624 x 1110684 x 1110744 x 1110
Water mantle volumeL60758296106134145162
Combustion chamber volumeL55627494103170191212
Required chimney draughtPa/mbar16 /0.1620/0.2021/0.2123/0.2324/0.2438/0.3847/0.4756/0.56
Insulation boilerHigh-efficiency thermal wool
Insulation doorsHigh-efficiency thermal wool
Recommended fuelWood, humidity 20%, wood briquettes, wood+coals, wood+fruit pits / broken nuts
Loading door sizemm330 / 250330/250390/250490/310490/310490/310550/310610/310
Max. length of firewood logsmm400400500500500600600600
Operating temperature range°C65-8565-8565-8565-8565-8565-8565-8565-85
Min. return water temperature°C6060606060606060
Operating pressurebar33333333
Cold water inletA, mmR1¼"/450R1¼"/450R1¼"/450R1¼"/450R1¼"/450R1½"/430R1½"/430R1½"/430
J, mm232232262312312312342372
Hot water inletB,mmR1¼" / 1165R1¼" / 1165R1¼" / 1165R1¼" / 1165R1¼" / 1165R1¼" / 1315R1¼" / 1315R1¼" / 1315
J, mm232232262312312312342372
Sleeve for sensor of safety valveK, mmG½"/1074G½"/1074G½"/1074G½"/1074G½"/1074G½"/1225G½"/1225G½"/1225
Safety heat evacuator inlet/outletE, mmR½"/1072R½"/1072R½"/1072R½"/1072R½"/1072R½"/1220R½"/1220R½"/1220
FlueF, ø / mmø150 / 940ø150 / 940ø150 / 940ø180 / 925ø180 / 925ø200 / 1050ø200 / 1050ø200 / 1050
J, mm232232262312312312342372
Flue cleaning openingO, mm150/70150/70150/70150/70150/70150/70150/70150/70
DrainY,mmmG½" / 232G½" / 232G½" / 232G½" / 232G½" / 232G½" / 232G½" / 232G½" / 232
J, mm232232262312312312342372
Temperature indicatorTYes
Thermostatic graught regulatorRYes
Air intake flapVYes
Burner flange (optional)Z, ø mm176176176176176176215215
Ash-and-soot containerXYes



For product measurements, they should be read as follows:

Cold water inletA, mmR1¼ "/ 450
Y, mmmG½ "/ 232

A is shown in the previous diagram. "R1¼" and "G½" are the measure in inches of the opening. "R" is male and "G" is female. The measurements in inches indicate the distance between the floor and the opening.


Recommended clearances between the boiler and walls


Burnit WBS

Relation between wood heating value and water content

Burnit WBS

Elements of boiler housing, model WBS

Burnit WBS

Boiler size and chimney parameters


Burnit WBS

Connecting the safety heat exchanger

Burnit WBS

1. Water supply network (pressure 6-10 bar)
2. Drainage (sewerage)
3. Boiler WBS
4. Safety heat exchanger inlet
5. BVTS valve sensor
6. Safety heat exchanger outlet

Connection of BURNiT WBS boiler to three-way valve

Burnit WBS

Connection of BURNiT WBS boiler to P type buffer tank and three-way valve

Burnit WBS

Connection of BURNiT WBS boiler to combi tank KSC2, flat plate solar collector PK and three-way valve

Burnit WBS

Connection of BURNiT WBS boiler to solar tank SON, buffer thank P, flat plate solar collector PK and three-way valve

Burnit WBS