






A manually loaded boiler in which the fuel combustion process is electronically controlled based on the exhaust gas temperature. The controller also regulates the operation of the central heating pump and the domestic hot water pump. Air for the fuel combustion process is forced by a blower fan using a multipoint direct feed system into the fuel combustion zone, significantly improving the process parameters.
The high efficiency of the device is ensured by the proven heat exchanger design with horizontal flue gas passages, and a fixed water grate that accelerates the heat uptake from the combustion chamber.
Efficient fuel loading is facilitated by a large, slanted loading opening, and the device’s extended working hours are made possible by a capacious loading chamber.
The NZ version with a reinforced construction, built-in cooling coil, and complete safety fittings allows for installation in a closed system. The NZ version is subject to an additional fee as per the Boiler Equipment Price List.
(*) – additional paid option, installed upon customer’s request.
Nominal power. | kW | 12 | 15 | 20 | 25 | 30 | 35 |
Minimal power. | kW | 3,6 | 4,5 | 6,0 | 7,5 | 9,0 | 10,5 |
Power range | kW | 3,6-12 | 4,5-15 | 6,0-20 | 7,5-25 | 9,0-30 | 10,5-35 |
Energy efficiency class | D | D | D | D | D | D | |
Heated area*. | m2 | Up to 120 | Up to 150 | Up to 200 | Up to 250 | Up to 300 | Up to 350 |
Single fuel load. | kg | ~21 | ~30 | ~41 | ~51 | ~65 | ~75 |
Fuel consumption**. | kg/h | 1,8 | 2,2 | 2,9 | 3,7 | 4,4 | 5,1 |
Optimum thermal efficiency | % | 85,0-85,8 | |||||
Max. permissible working pressure | % | 2,5 | |||||
Required exhaust gas draft | Pa | 22 | 23 | 26 | 28 | 30 | 31 |
Exhaust gas temperature for nominal power | °C | 197-248 | |||||
Flue gas mass flow for nominal power. | g/s | 8,5 | 10,4 | 11,6 | 15,4 | 18,5 | 20,8 |
Water temperature at supply min./max. | °C | 65/85 | |||||
Water temperature at return min. | °C | 55 | |||||
Temperature adjustment range | °C | 45-85 | |||||
Chimney dimensions. | cm x cm | 14×14 | 14×14 | 14×14 | 16×16 | 17×17 | 18×18 |
Chimney dimensions. | Ø mm | 160 | 160 | 160 | 180 | 190 | 200 |
Minimum height of the chimney | m | 6 | 6 | 7 | 7 | 8 | 8 |
Heating surface | m2 | 1,7 | 2,1 | 2,5 | 2,8 | 3,4 | 3,8 |
Boiler water capacity | l | 67 | 77 | 92 | 104 | 121 | 141 |
Boiler weight *****. | kg | 282 | 315 | 352 | 400 | 466 | 494 |
Width | mm | 616 | 666 | 666 | 716 | 816 | 816 |
Maximum depth. | mm | 875 | 875 | 945 | 975 | 975 | 1045 |
Maximum height***. | mm | 1350 | 1400 | 1460 | 1460 | 1460 | 1460 |
Loading opening dimensions. | mm | 258×188 | 258×188 | 308×188 | 358×188 | 458×188 | 458×188 |
Diameter of supply and return connections. | 1½” | ||||||
Drain port diameter | ½” | ||||||
Power supply | V/Hz | ~230V/50Hz | |||||
Maximum power consumption. | W | 44 | |||||
Operating pressure of the coil min/max****. | bar | 2/6 |
*The maximum heated area has been estimated for an individual heat demand of q = 80 W/m².
**Fuel consumption for anthracite coal with a heating value of 28,997±300 kJ/kg.
***The height of the OPTIMA KOMFORT PLUS NZ boiler can be further adjusted using the included feet. The feet have an adjustment range of 28-40mm.
****In case of higher pressure, use a pressure reducer.
*****The weight of the boiler depends on the equipment.
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Do you need device selection?
If you want to install a new heat source, it is worth paying attention to DEFRO devices, a Polish manufacturer with many years of experience in the heating industry. Our specialists will help you choose the right boiler and its power, and distributors and installers will take care of the assembly and commissioning, and all you need to do is enjoy the warmth and comfort. The distribution network of our products is divided into regions for which managers and salespeople are responsible.