5 class PELLET BOILER K2-20DG (20kw)

Multipurpose bottom combustion solid fuel boiler with pellets burner

  • High efficiency
  • Large fuel load
  • Fuel is loaded from the front or top
  • Automatic adjustment of boiler temperature
  • Secondary air supply
  • Secondary burning chamber with refractory concrete catalyst
  • Smoke exhaust, ignition and draught dampers
  • Fire grates shaking mechanism
  • Heat exchanger cleaning from both boiler’s sides
  • Emergency cooling coil
  • Possibility to mount electric heating element
  • Possibility to install smoke exhauster
  • Easy to modify for firing on solid fuel
  • Housing inner wall steel plate thickness – 6 mm
  • Warranty for boiler frame – 4 years

BURNER BurnPell X Mini

  • Patented fuel mixing inside of burning chamber system
  • Control panel contains mounted emergency thermostat
  • Automatic ignition, cleaning, combustion control
  • Equal electronic output correction
  • Automatic start up after power loss
  • High combustion efficiency – up to 99 %
  • Burner combustion chamber is made of heat proof stainless steel
  • Protection against to back fire inside fuel feeding system
  • Low el. power usage


  • Real time precise operation parameters
  • User and service menu
  • Programming of weekly operation cycle 
  • Controls one heating circuit with servo drive, three-way or four-way valve, and hot water preparation
  • Controls up to 5 heating circuits with additional modules
  • Possibility to control burner via room console using thermostat
  • Possibility to control burner via internet, having connected internet module ecoNET
  • Possibility to control by lambda probe
Boiler model   K-2-20NDG
Burner model   BurnPell X.Mini
Control panel   Scontrol  EM892
Minimal power / Nominal power, kW   5 / 20

Heated area (Energy efficiency acc STR 2.01.02:2016), m2

B class premises

230 … 700

C class premises

112 … 334

Pellets size, not bigger than, mm   Ø 6 – 8 
Fuel consumption at nominal output, kg/h   4,7
Efficiency, %   89
Combustion chamber volume, while burning logs, dm3 (l)   136
Water volume in the boiler, l   72
Flue channel diameter, mm   Ø 160
Draught in a burning chamber (firing pellets), Pa   12
Minimum chimney draught (firing logs), Pa   19 … 24

Overall dimensions of the boiler with mounted burner, without bunker and auger pellets conveyor, HxBxL (L k ), mm


1350x770x1430  (1210)

Mass (boiler + burner) / (brutto), (±10%), kg   365/ 385


1  Firing manually – logs, pieces of waste wood, briquettes. It is not recommend to fire logs with moisture contain exceeding 25 %.

Boiler K2-20DG (20kw) scheme:

  1. Burner door with burner opening
  2. Burner
  3. Boiler
  4. Draught control
  5. Boiler’s controller
  6. Secondary air input hole
  7. Ash box
  8. Fire grates
  9. Furnace cast iron door
  10. Flexible armed hose
  11. Screw pellet conveyor
  12. Pellet bunker



Principal circuit diagram (open type) of solid fuel boiler is recommended using three-way mixing valves with boiler, solar collector and open water expansion vessel.



5 class certificate


Product Information Sheet
Delegated Regulation (EU) 2015/1187
Supplier name or trademark UAB “Kalvis”
Model identifier K-2-20DG
Energy Efficiency Class A+
Rated heat output 20 kW
Energy Efficiency Index 116
Seasonal space heating energy efficiency 78 %
Specific precautions See product passport


Link to the EPREL system

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