The THERM 28 KDZ5.A condensing boiler is designed for heating the heating system and for heating water in a 55 l integrated storage tank. The water is heated in the same way as for a combination of a boiler and an external indirect heating storage tank. The difference is only in the fact that for the type with a built-in storage tank, the storage tank is neatly hidden under the boiler cladding. It can be used anywhere there is no technical room and the boiler is located in the interior of the house or the flat. The advantage is that there are no interconnections between the boiler and the storage tank.

The THERM 28 KDZ5.A wall-mounted boiler provides excellent ecological operation. An energy saving pump is a matter of course, which ensures electricity savings of up to by 50% compared with similar pumps and fluent regulation of the boiler power from 6.6 kW. Suitable combination with the floor heating of the building, as well guaranteed functionality during the generational replacement of the existing boiler unit and the heating system.


Recommended retail price: on request

eu_flagThe product THERM 28 KDZ5.A 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 5 View the ErP label View the ErP label
  • Saving of operating costs after replacing the old boiler
  • Energy saving pump - electricity savings of up to 50 %
  • Use of new HDIMS 20-TH20 automatic control system
  • The boiler includes a stainless indirect heating storage tank with a volume of 55 l
  • Fluent regulation of the boiler output
  • Option of regulation according to the spatial or outdoor temperature (equithermal regulation)
  • Communication between the boiler and the regulator using the OpenTherm+ protocol
  • Suitable combination with the floor heating system
  • Excellent ecological operation
Technical data Unit THERM 28 KDZ5.A
Class of seasonal energy efficiency of heating - A
Energy efficiency class of water heating - A
Declared loading profile - XL
Nominal thermal input power kW 26.4
Min. – max. thermal output for heating kW 6.6 - 28.0
Fuel - natural gas / propane
Gas consumption - natural gas m3/h 0.68 - 2.85
Gas consumption - propane m3/h 0.24 - 0.93
Min. – max. overpressure of heating system bar 0.8 - 3.0
Maximum input pressure of heating water °C 80
Boiler efficiency % 98 - 106
Volume of expansion unit l 7
Volume of the integrated tank l 55 (stainless)
Volume of expansion unit of DHW l 2
Nominal supply voltage / frequency V/Hz 230/50~
Auxiliary electricity at rated heat input W 66.1
Level of coverage of electrical part - IP 41 (D)
Diameter of smoke flue mm 60/100, 80/125, 2x80
Dimensions: height / width / depth mm 800 / 800 / 390
Weight of boiler kg 67
Order number - 1058.7