THERM 24 KDNS is a stationary gas condensing boiler designed for heating systems. The construction and the arrangement of components makes the boiler suitable for standing on the floor or on a pedestal. The controls are on the top side of the boiler, as well as distribution connections, thanks to which the boiler can be easily installed instead of older types. It is ideal for installation in cellars and basements with a very low ceiling where a standard hanging boiler cannot be installed.

The boiler may be equipped with a condensate pumping station that is not standardly included with the boiler. Heating domestic hot water can be provided in an external non-heating tank, using an external three-way valve. For heating, the boiler has a heating capacity from 4.6 to 26.0 kW.


Recommended retail price: on request

eu_flagThe product THERM 24 KDNS complies all legislative, safety, healthy and environmental requirements of the European Union and CE mark enables the free movement of products within the market of the European Economic Area.

Emission category NOx 6 View the ErP label
  • Continuous boiler output control
  • Energy-saving circulating pump with electronic control
  • Microprocessor control automation
  • Stainless condensation exchanger
  • Optional water heating in an external tank using an external three-way valve
  • Optional regulation according to the spatial or outdoor temperature (equitherm regulation)
  • LCD display for reading parameters
  • High efficiency using the principle of condensation of water vapours from burnt gases
  • Communication between the boiler and the regulator using the OpenTherm+ protocol
  • Suitable for use with a floor heating system
  • Exceptionally environmentally friendly – meets the European emission standard and the requirements of the Act on the Protection of Air effective since 2018
  • Reliability and long service life
  • Very quiet operation
VIDEO: First stationary condensing boiler THERM 24 KDNS
Technical data Unit THERM 24 KDNS
Class of seasonal energy efficiency of heating - A
Nominal thermal input power kW 24.5
Min. – max. thermal output for heating kW 4.6 - 26.0
Fuel - natural gas / propane
Gas consumption - natural gas m3/h 0.46 - 2.70
Gas consumption - propane m3/h 0.20 - 1.03
Min. – max. overpressure of heating system bar 0.8 - 3.0
Maximum input pressure of heating water °C 80
Boiler efficiency % 98 - 107
Volume of expansion unit l 7
Nominal supply voltage / frequency V/Hz 230/50~
Auxiliary electricity at rated heat input W 70.0
Level of coverage of electrical part - IP 41 (D)
Diameter of smoke flue mm 80/125, 2x80
Dimensions: height / width / depth mm 935 / 510 / 458
Weight of boiler kg 33
Order number - 1095