Gasification wood boiler BLAZE NATURAL PLUS

Wood gasification boiler

for lump wood, briquettes, wood chips and sawdust

  • Unique wood boiler with exhaust fan and control unit for output regulation
  • Certified output adjustability of 30–100 % allows installation WITHOUT a buffer tank
  • 4 patents in a single boiler
  • Excellent price/performance ratio
  • Simple replacement of existing non-compliant boilers
  • Low fuel consumption, long boiler life
  • Efficiency 90 % over the entire power range
  • Complies with Ecodesign, boiler energy class A+
  • Certified boiler according to EN 303-5, emission class 5
  • Very low electricity consumption. With sufficient chimney draught, operation without fan is possible

The controller allows easy adjustment of the desired boiler output using a rotary control. The controller controls the output according to the flue gas temperature. A separate button switches the exhaust fan to maximum power for trouble-free fuel loading without smoke.

  • Class 5

Advantages of a wood
gasifying boiler BLAZE


    Mechanical detection of residual fuel

    This unique system provides automatic stable heat (embers), causing the fan to switch off when the level of the fuel decreases. This accurate detection maintains the hot embers layer in the combustion chamber for several hours, reducing the number of times a new fire is started in the boiler per season.


    Protection against low temperature corrosion

    The built-in thermostat with a temperature setting at 60°C and a special structure for mixing inside the boiler protects the boiler. Option of gravity connection to the buffer tank without pumps. Considerable savings during installation and safe operation. 7-year warranty on the boiler body, with no additional conditions. (Optional accessory for selected boilers)


    Three-way air supply

    Ensures uniform burning of fuel and allows to burn fuels of various dimensions (wood chips, sawdust, briquettes even lower quality). Pre-drying air, which is supplied (if necessary) into the upper part of the chamber will dry up any damp fuel in order to be able to burn it well and maintain high boiler efficiency and low emission values.


    Beam nozzle

    BN and BG models use a special design beam-shaped bottom, which ensures high quality gasification of the fuel with very low emissions. At the same time, it allows operation on chimney draft only.

  5. Corrosion protection with an insulated compact hot chamber system

    Where the walls of the stoking chamber are not directly cooled by water – they are hotter, which prevents condensa-tion. The service life of these boilers is many times longer than that of conventional gasification boilers. It also allows the combustion of moist fuel, without significantly reducing the boiler's service life. The increased temperature of the walls prevents the unpleasant deposition of tar in the stoking chamber. The compact gasification chamber is a separate element that is insulated from the walls of the water boiler. The chamber can be replaced.

  6. Inclined bottom of the gasification chamber

    Provides automatic ash removal from the combustion chamber during combustion, completely eliminating the need to clean it before firing it up again.

SEMI-AUTOMATIC operation of the pyrolitic boiler

After 8 hours
Up to 12 hours
After 12 hours
After short time


Stoking - after stoking fuel to whole volume of the stoking chamber the combustion time is up to 8 hours depends on the fuel type and preset boiler output.


After 8 hours - when the fuel level decrease under the detection threshold, then the sensor sends signal and controller switch off the fan. This stops the burning process.


Up to 12 hours from the first fuel stoking, there are still hot coals (embers) in the chamber, so it is sufficient to add directly bigger logs, start the fan and combustion continues. For other models of boilers with electronic control unit this time reaches up to 24 hours from the first connection.


After 12 hours and more after first fuel stoking there will not be hot coals (embers). There will remains fuel residual in the form of charcoal. In such a case is suifficient to start the fan and with small piece of paper fire up the layer of charcoal.


After short time the charcoal fires up very well. Then it is possible to add even larger pieces of wood. The residual fuel detection mechanism provides user‘s high operation comfort due to lack of new ignitions, when user must clean the boiler and cut small pieces of wood and wait until the boiler ignites successfully.


Boiler with three-way combustion air supply

Boilers can easily control the distribution of the air entering the fuel (pre-drying air is supplied over the fuel). Therefore the boiler can be adapted to various fuels. This effectively burns fuel that can be easily burn (wood chips, small briquettes), but also fuels that burns hard (large logs, wet wood).

Cut through boiler for wood BLAZE NATURAL PLUS with three-way air supply

Dimensions of boiler

Dimensions of wood boiler BLAZE NATURAL PLUS
  BNP 17 BNP 25 BNP 40 (35)
  mm mm mm
A 1200 1200 1200
B 450 530 714
C 584 664 664
D Ø149 Ø149 Ø149
E G6/4" G6/4" G6/4"
F 104 104 104
G 939 939 939
H G1/2" G1/2" G1/2"
I 721 721 721
J 471 471 471
K G2 1/2" * G2 1/2" * G2 1/2" *
L 280 370 370
M 100 130 130
N 113 113 113
O 995 995 995
P 200 200 200
Q 120 120 120
R Ø141 Ø141 Ø141
S 18 18 18
U 960 1040 1040
V 1176 1176 1176
W 680 680 870
X 850** 850** 850**
Y 225 265 324
Z 627 707 707

* cold water inlet to the boiler reduced to G6/4"
** maximum transport dimension after removing the fan

Technical parameters

  BNP 17 BNP 25 BNP 40 (35)
Nominal output (kW) 17 26 40
Adjustable output (kW) 4,9–17 7,6–26 12–40
Efficiency (%) 90,1 90 90
Emission class 5
Ecodesign YES
Energy class A+
Logs length (mm) 250 330 500
Stocking chamber volume (l) 40 80 120
Boiler weight (kg) 245 340 440
Maximal operation pressure (bar) 3
Exchanger water volume (l) 32 40 55
Required chimney draft (Pa) 10 10 10

Documents to download

Wood gasification, combined and automatic boilers for wood and pellets
PDF Boiler operating and installation manual BLAZE NATURAL PLUS