Wood fired boiler 20kW to 40kW (biomass) BURNiT PyroBurn Alpha Plus


2 802,80 € tax incl.


A highly-efficient wood gasifying boiler, designed for economical and ecological heating of medium to large-sized premises (20, 30 or 40kW). The PB Alpha PLUS boiler provides intuitive operation interface, cleaning system,  heat output regulation as well as sophisticated safety systems.

Madie in Europe

Available on order

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Boiler PyroBurn Alpha PLUS

Owing to the wood gasification technology employed the PyroBurn Alpha boiler reaches efficiency of above 90% and saves fuel. The water mantle embraces the combustion chamber in full to utilize the emitted heat most efficiently.

Built-in high temperature ceramic plates ensure uniform heat distribution and protection of the water mantle from the extreme heat produced by wood gasification (up to 1200°C). A complex of safety devices ensure its safe operation.

Tested and approved according to EN 303-5, class 5.

Boiler warranty : 2 years


Wood gasification

The wood in the primary burning chamber is fired in a low-oxygen environment reaching about 580°С. It starts degrading to a combustible gas of carbon compounds which is directed to the orifice of the secondary combustion chamber. There, the gas is enriched with secondary air and ignites to reach temperature of up to 1200°C.
Before leaving the boiler body, the gas passes through a flue with built-in spiral turbulators where it gives away its heat to the water mantle and cools down to 150°С. Thanks to the wood gasification principle the fuel is most efficiently consumed with minimum carbon emissions and ash.

1.Incoming air;
2.Primary air
3.Secondary air;
4. Ignition;
5. Pyrolysis combustion;
6. Fume exhaust fan;
7. Flue

Product Features




  • The built-in proportional-integral derivative controller monitors the burning process and controls the fan speed to achieve optimal yield and economy of fuel;
  • Fume exhaust fan;
  • Cleaning system (manual);
  • Fume extraction device on the upper combustion chamber keeps smoke from polluting the boiler room during reloading;

Boiler PyroBurn Alpha PLUS

  • Large firebox door ensures easy loading even with bigger logs (length of logs up to 50 cm);
  • Combustion chamber protected on all sides by ceramic plates;
  • Eyepiece for viewing the combustion process;

Safety devices


  • Upon reaching 95°С the controller turns the fan off and activates the pumps for domestic hot water and heating system. An independent STB thermostat shuts down the fan upon reaching 99°С.
  • Safety heat evacuator;
  • Pressure relief valve 3 bar;

Chart boiler PyroBurn Alpha Plus
1. Controller
2. Housing
3. High efficiency thermal insulation
4. Safety heat evacuator
5. Water mantle (jacket)
6. Wood-loading chamber
7. Pyrolysis combustion chamber
8. Hot water outlet
9. Flue
10. Fume exhaust fan
11. Primary air flap
12. Secondary air flap
13. Cold water inlet
14. Cleaning system (manual)





Technical specifications

Chart boiler PyroBurn Alpha Plus


PyroBurn Alpha Plus
Nominal heat output / Min-Max heat outputkW18.9 / 15-2028.9 / 27-3237.7 / 35-40
Mass flow of exhaust gases, Max. heat outputkg/s0.0170.0210.028
Height Hmm125512901430
Width L x Depth Dmm679 x 930765 x 1090765 x 1160
Water mantle volumeL526875
Combustion chamber volumeL76132162
Required chimney draughtPa/mbar10-20 /0.10-0.2010-20 /0.10-0.2010-20 /0.10-0.20
Insulation boilerHigh-efficiency thermal wool
Insulation chamberCeramic plates
Insulation doorsHigh-efficiency thermal wool + ceramic plates
Average power consumptionW100100100
Electric power supplyV/Hz230/50230/50230/50
Recommended fuelWood, humidity 15%, wood briquettes
Burning time partial / full loadhmin. 2hmin. 2hmin. 2h
Fuel consumption for heating season14.5 / 1820 / 2532 /40
Loading door sizemm400 / 220490 / 260490 / 260
Max. length of firewood logsmm330500500
Recommended size of buffer tankL100015002000
Exhaust gas temperature (operation mode)°C130-150130-150130-150
Operating temperature range°C65-8565-8565-85
Min. return water temperature°C606060
Operating pressurebar333
Cold water inletA, mmR1¼"/130R1¼"/170R1¼"/170
Hot water inletB,mmR1¼" / 1150R1¼" / 1250R1¼" / 1325
Sleeve for sensor of safety valveKYes
Safety heat evacuator inlet/outletE, mmR½"/1070R½"/1160R½"/1235
FlueF, ø / mmø150 / 970ø150 / 1075ø150 / 1150
J, mm338382382
DrainY, mmG½" / 60G½" / 100G½" / 100
Cleaning opening upper01,mm360 / 120455 / 120455 / 120
Cleaning opening lower02, mm325 / 142350 / 140350 / 140
Air intake flap - primary airV1, mm610655690
Air intake flap - secondary airV2, mm460505540
Fume exhaust fanW, mm790890970
Fume extraction deviceMYes
Cleaning systemSYes
Eyepiece for viewing the combustion processPYes


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 PyroBurn Alpha PLUS

Relation between wood heating value and water content

Burnit PyroBurn Alpha PLUS

Connecting the boiler to a chimney


Burnit PyroBurn Alpha PLUS

Connecting the boiler to the mains power supply

Burnit PyroBurn Alpha PLUS

Connecting the safety heat exchanger

Burnit PyroBurn Alpha PLUS

1. Water supply network (pressure 6-10 bar water temperature 8-15 °С)
2. Drainage (sewerage)
3. Boiler PB Alpha PLUS
4. Safety heat exchanger inlet
5. BVTS valve sensor
6. Safety heat exchanger outlet


Connection of PyroBurn Alpha PLUS boiler to three-way valve

Burnit PyroBurn Alpha PLUS

Connection of PyroBurn Alpha PLUS boiler to P type buffer tank and three-way valve

Burnit PyroBurn Alpha PLUS

Connection of PyroBurn Alpha PLUS boiler to combi tank KSC2, flat plate collector РК and three-way valve

Burnit PyroBurn Alpha PLUS

Connection of PyroBurn Alpha PLUS boiler to solar tank SON, buffer tank P, flat plate collector РК and three-way valve

Burnit PyroBurn Alpha PLUS