1:10
Power modulation
ISC
Combustion system
106 %
High efficiency
H2
Ready
ATTACK Condensing KT 20 is a wall-mounted gas boiler for heating with the possibility of variable connection of a hot water cylinder. After connecting the boiler to an additional cylinder, you can not only heat but also prepare DHW and satisfy the needs of even a large household. The boiler achieves significant gas consumption savings thanks to continuous power modulation up to 1:10, and the Intelligent Combustion System ISC can operate even with a minimum power from 2.4-33 kW, which is a great advantage for family houses. The boiler can also be controlled according to the outdoor temperature (weather-compensated regulation).
The gas boiler is suitable for every type of house or apartment
ATTACK Condensing KT 20,28 with power up to 29.5 kW can heat a family house with an area of up to 400m2. Any DHW heating cylinder can be connected to the boiler. Offered volumes are from 80-200 l.
Gas boiler and connection
To use a gas condensing boiler, you must have a natural gas connection, which belongs among the most ecological fuels among fossil fuels. For those who would like to have a condensing boiler even without a natural gas connection, there is a solution. The boiler can be connected to propane. ATTACK Condensing KT 20,28 can be used for several types of gas (G20 natural gas or G31 propane; changing and setting the fuel must be performed by an service technician)
Why choose a gas boiler
Low acquisition cost of the device compared to biomass boilers or heat pumps – it belongs among the cheapest and least maintenance-demanding sources.
High power modulation
ATTACK Condensing KT has a high range of power modulation up to 1:10. This is the main technical advantage of our gas boilers. This modulation system consists in the fact that the boiler can operate at low power, for example (starting from 2.4 kW). It achieves a high efficiency of up to 106% with energy class A for heating.
The intelligent combustion system controls combustion and adjusts values such as gas flow to always achieve the correct air/gas ratio.
- Reduction of gas consumption
- Lower CO2 emissions
- Shorter time for installation and boiler setting
- Modulation range 1:10
- Reduction of the number of off/on cycles
- Extension of boiler service life
Quality and efficiency
In the production of boilers, we used brass components for the hydraulic assembly, ensuring maximum product reliability.
The new brass hydraulic group is equipped with:
- High-efficiency pump
- Three-way valve
- By-pass
- Flow regulator with filter
- Drain valve
- DHW temperature sensor
Technical information about important parts of the boiler that might interest you.
Air supply
It serves to supply the air necessary for combustion.
Flue gas discharge
It is used to remove flue gases from the boiler combustion chamber.
Condensation exchanger
It transfers heat from the flue gases to the heating water.
Gas valve
Regulates the gas supply for combustion
Siphon
Serves as an odor trap, preventing odors from the combustion chamber from penetrating into the external waste
Modulating pump
Ensures circulation of heating water in the hot water system
Three-way valve
Ensures the direction of flow of heating water into the heating system or into the indirectly heated DHW exchanger
Mixer
It serves to create a gas mixture for combustion
Burner
A gas mixture burns on its surface, releasing heat.
Fan
It serves to supply the gas mixture to the gas burner.
Safety valve
It is a safety element that serves to reduce pressure in the heating system in the event of overpressure.
Technical data and documents for download
The ATTACK Condensing KT gas condensing boiler achieves a high combustion efficiency of up to 106% with a power modulation of 1:10. The ISC intelligent combustion system with high-quality components and processing guarantees a long service life. Find out more about other technical data.
- High power modulation 1:10
- ISC intelligent combustion system
- H2 ready
- High combustion efficiency 106%
- Hot water heating in an external cylinder
- Wide power range 2.4-29.5 kW
- Stainless steel exchanger
- Frost and bacteria protection
- Brass hydraulic group of components
| Parameter | Unit | ATTACK CONDENSING KT20 |
| Max. thermal output of central heating | kW | 25 |
| Min. thermal output of central heating | kW | 2,5 |
| Max. thermal output of central heating (50/30 °C) / (80/60 °C) |
kW | 21/19,4 |
| MIN. thermal output of central heating (80/60 °C) |
kW | 2,4 |
| Gas connection pressure G20 | mbar | 20 |
| Gas connection pressure G31 | mbar | 37 |
| Emission class NOX | – | 6 |
| Max. / min. operating pressure by heating | bar | 3/1 |
| Efficiency class by directive 92/42 EHS | – | A |
| El. voltage | IP | IP X5D |
| El. input | V/Hz | 240/50 |
| El. input by D.H.W. preparation | W | 73 |
| Weight of the empty boiler | kg | 28,1 |
| Dimensions (W × H × D) | mm | 400x727x324 |
| Parameter | Unit | ATTACK CONDENSING KT28 |
| Max. thermal output of central heating | kW | 33,2 |
| Min. thermal output of central heating | kW | 3,5 |
| Max. thermal output of central heating (50/30 °C) / (80/60 °C) |
kW | 29,5/27,4 |
| MIN. thermal output of central heating (80/60 °C) |
kW | 3,3 |
| Gas connection pressure G20 | mbar | 20 |
| Gas connection pressure G31 | mbar | 37 |
| Emission class NOX | – | 6 |
| Max. / min. operating pressure by heating | bar | 3/1 |
| Efficiency class by directive 92/42 EHS | – | A |
| El. voltage | IP | IP X5D |
| El. input | V/Hz | 240/50 |
| El. input by D.H.W. preparation | W | 86 |
| Weight of the empty boiler | kg | 33,4 |
| Dimensions (W × H × D) | mm | 400x727x324 |
High-quality processing
We manufacture all our products with an emphasis on the selection of quality materials and the use of correct technologies and procedures. Brass components of the hydraulic assembly ensure maximum product reliability. Our own know-how is a guarantee of reliable service and long life.
Possibility of cascade connection
We designed the Condensing KT boilers to allow cascade connection of up to 4 boilers. For cascade connection, you must use a cascade controller, which can be purchased as an accessory. The cascade controller intelligently manages connected boilers and provides perfect control over the connected system.
Comfort with OpenTherm regulation
We can also increase the comfort of a gas boiler using a regulator that will adjust the temperature according to the outdoor temperature. The temperature will thus automatically adapt to changes in your household versus the outdoor temperature. This method of regulation can more effectively utilize the boiler’s power and at the same time save you money on operation.
In addition, you get greater comfort because the regulator takes care of everything for you. If, however, you want even more convenience, it will be provided by an additional control with OpenTherm two-way communication.
* the weather-compensated regulator is not part of the boiler delivery.
OpenTherm regulation (optional accessory)
We allow connecting OpenTherm regulation, which can not only turn on the boiler but also detect the difference between actual room temperature and the set value, allowing boiler power modulation according to the thermal needs of the system. OpenTherm regulation guarantees lower consumption, more stable temperature, and greater comfort for the user. Get maximum comfort.
Smart remote control
We offer optional accessory OpenTherm room thermostat OT80 and Wifi modem OT81 for the boiler, with which you can control your boiler remotely via the ATTACK Condens mobile application.
Choose a service partner for installation
Creating a high-quality and prompt service network for our customers is very important to us. Our service partners provide prompt service assistance to every customer throughout the year.
