Vitocrossal 300 CU3A - meets all your needs

Take advantage of these benefits

  • Converts up to 98 percent of the energy used into heat
  • Quiet, economical and environmentally responsible
  • Smooth stainless steel heat exchanger surfaces create self-cleaning effect
  • Lambda Pro Control combustion controller for all gas types
  • Lower flue gas inspection costs with inspection interval extended to 3 years
  • Energy efficiency class A

Please note: This product is not available in the UK

The leading floorstanding boiler

The Vitocrossal 300 is a leading product amongst floorstanding gas condensing boilers.

Its proven MatriX gas burner with Lambda Pro Control combustion controller automatically adjusts to fluctuating gas qualities in natural gas and LPG.

Its vertically arranged heat exchanger surfaces exploit the condensation energy in its hot gases particularly well, with up to 98 percent of the energy used being converted into heat.

With an output of 2.5 to 60 kW, this compact gas condensing boiler is suitable for heating apartment buildings and public or commercial premises.

Convenient Vitotronic control unit

System users and contractors benefit equally from the easy-to-use Vitotronic control unit, as the structure of its menu is logical and clearly laid out and the unit is backlit, rich in contrast and easy to read.

If in doubt, a help function informs users of the next steps to perform. The graphic user interface also displays heating curves and solar yield if a solar thermal system is connected.

Inox-Crossal-stainless steel heat exchanger

Advanced condensing technology

The stainless steel Inox-Crossal heat exchanger provides ideal conditions for utilising condensing technology. The smooth stainless steel heat exchanger allows the condensate created by the condensing process to simply run off downwards. Combined with the smooth stainless steel surface, this creates a permanent self-cleaning effect, thus ensuring that the condensing technology is utilised at a permanently high level, resulting in a
longer service life whilst also reducing the maintenance effort.

The highly effective heat transfer and the high condensation rate enable standard seasonal efficiencies [to DIN] up to 98 % (Hs) [gross cv] / 109 % (Hi) [net cv] to be achieved. These high levels of standard seasonal efficiency are the result of the countercurrent principle of hot gases and boiler water, along with intensive turbulation of the hot gases as they pass over the heating surface.

Vitoconnect 100 creates the connection

The Vitoconnect 100 interface is required to operate via the app. Retrofitting of old gas condensing boilers of the Vitodens series (from 2004) is possible at any time.

Vitoconnect 100
ViCare App & Vitotrol Plus App

ViCare App

The ViCare app allows the user to control their heating system via a smartphone. The operating status can be viewed at any time and, in the event of a fault, contact can be made quickly and easily with the installation company previously registered in the app.

Vitotrol Plus App

The Vitotrol Plus app allows the remote control of all heating circuits in a heating system. It is used to set operating programs, setpoints and time programs. Operating and consumption data are also displayed. It also allows the display of solar yields.


A perfect match – System technology

"The whole is greater than the sum of its parts". Following this philosophy, Viessmann supplies more than high quality, reliable and effective heating components. In fact, all products are part of a matching total concept, where all components complement one another. After all, only perfect interaction between all system components can draw out the maximum potential of our innovative leading technology.

Viessmann system technology incorporates everything you need for a reliable and economical heating system: From the Vitotronic control unit with wireless remote control, powerful Vitocell DHW cylinders for the highest DHW convenience, right up to high grade solar thermal systems for cost effective central heating backup.

Product cross-section


Output (kW)
2.5 to 60 kW
Standard seasonal efficiency [to DIN]
98 % (Hs) [gross cv] / 109 % (Hi) [net cv]
Energy efficiency class
Natural Gas & LPG
Application range
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Detached and two-family houses, apartment buildings, commerce, municipal offices, new build and modernisation projects
Vitotronic 200 control unit with plain text and graphic display, can be operated by means of the Vitotrol app
DHW heating
Additional DHW cylinder required, resulting in a high level of DHW convenience
Additional features
Modulating MatriX gas burner with wide modulation range
Produktschnitt Gas-Brennwertkessel Vitocrossal 300 Typ CU3A