kwkd zębiec kocioł

*Illustrative photo


Lower combustion boiler

The KWK type boiler is a heating unit with lower combustion of long-flame solid fuels. It was designed with the participation of the Research Institute, so it is characterised by high efficiency. Boilers of this type enjoy great popularity due to easy handling. They are great for the heating of houses, garages, utility buildings or commercial spaces.

Easy to use

The economical and fault-free operation of the boiler depends on its correct parameters and the constant control of its work. Burning temperature can be easily adjusted by means of a knob on the hinged flap located on the ash pan door or by means of an automatic draught regulator. When he large combustion chamber is topped up and correct combustion parameters are set, the boiler will produce heat for many hours, without any intervention.

Rapid heat transfer

The KWKD type boiler combines the best solutions which enhance its efficiency, which help to provide heat in a short time. The compact design of the exchanger and high grade materials as well as a fixed water grate guarantee a high thermal output despite the boiler’s small dimensions. The heavy, fixed grate is quicker to deliver heat from the fuel to the circulating water, and this enhances the thermal efficiency of the unit. Heat dissipation is effectively reduced by means of an insulation mantle made with layers of steel lined with mineral wool. The thermal efficiency of KWKD boilers reaches 82%.

Reliable design

The design of these boilers is solid and resistant to high temperatures. The use of proven materials, such as boiler steel, guarantees stable operation for many years. Satisfactory insulation prevents heat loss and ensures maximum retrieval of energy, which help the boiler to reach high levels of thermal output quickly. KWKD boilers made by ZGM ZĘBIEC SA ensure a long service life free from unexpected failures.

Large combustion chamber

Combustion is controlled by means of an automatic draught regulator* or manually (*as an option at extra charge)

High combustion efficiency, up to 82%

Certified boiler plates P265GH

Quick and effective ash removal thanks to a cast iron, mobile grate.

Easy and quick operation.

36-month warranty for the leak-tightness of the water jacket

24-month warranty for service life and efficient operation

drewno paliwo
Hard coal Coke  


By means of a draught regulator


By means of a screw adjusting the position of the flap in the lowest door

Operation and Maintenance Manual for KWKD series KWKD 15 – product fiche KWKD 22 – product fiche

kwkd zębiec

Boiler Height Width Depth A B C Flue Burning chamber Charging hole F
D E height width depth width height
KWKD 15 1051 444 717 269 906 1090 140 110 330 338 275 212 167 507
KWKD 22 1217 506 745 290 1062 1252 160 130 370 400 275 317 197 569
Item Detailed data UOM Boiler size
1. Rated thermal output kW 15 22
2. Fuel hard coal, nut coal II
3. Heat efficiency at rated power % up to 82 up to 82
4. Heat output regulation range % of rated output 30 ¸ 100 30 ¸ 100
5. Max. leaving water temperature oC 95 95
6. Max. operating pressure MPa 0,15 0,15
7. Min. return water temperature oC 40 40
8. Max. operating pressure bar 1,5 1,5
9. Required draught Pa >24 >25
10. Min. chimney cross-section area as per PN-89/B-10425 cm x cm

Æ cm

14 x 14

Æ 16

20 x 14

Æ 18

11. Flue dimensions mm 140 x 110 160 x 130
12. Min. chimney height m 5 5
13. Water connections, inlet/outlet (threaded) mm Æ60,3 x 4 (2”) Æ60,3 x 4 (2”)
14. Charge capacity of the burning chamber dm3 42 50
15. Stoking door dimensions mm 175 x 220 205 x 324
16. Single-charge combustion at rated power godz. > 5 > 6
17. Boiler water capacity dm3 ~ 58 ~ 76
18. Weight of empty boiler kg 224 290
19. Overall dimensions Height mm 1051 1217
Width mm 444 506

with return duct (flue)

mm 717 745
ZĘBIEC boilers Thermal output [kW] Heated floor area [m2], based on heat transfer coefficient of walls (insulation)
U > 1 [W/m2K] U ~ 0,7 [W/m2K] U ~ 0,5 [W/m2K] U ~ 0,3 [W/m2K]
no insulation ~5 cm styrofoam ~8 cm styrofoam >10 cm styrofoam
KWKD 15 15 130 150 175 230
KWKD 22 22 195 220 260 340

Draught regulator

A draught regulator in solid-fuel boilers is a thermostatically operated device for controlling the water temperature in the boiler.
The thermostat head of the regulator monitors the water temperature in the boiler and via levers and a chain moves a flap to increase or reduce the airflow into the hearth.