Proven condensing technology

Operating costs for medium and large size heating systems are often not given due consideration. By modernizing the heating boilers, energy consumption and environmental impact can be reduced considerably.

Condensing boiler technology provides distinctive possibilities to lower gas consumption dramatically in apartment buildings, commercial, industrial and public buildings.

The benefits at a glance

  • High operating reliability and long service life due to the vertically arranged, corrosion-resistant Inox-Crossal heat exchanger surface made of stainless steel.
  • Energy savings and reduced impact on the environment through enhanced utilization of the latent heat contained in the flue gases.
  • Depending on the heating system water temperature, efficiencies in excess of 95% can be achieved through intensive flue gas condensation.
  • Easy transport into boiler rooms due to narrow design and low weight - an important factor in modernizing the boiler room.
  • Safe heat transfer ensured by wide dimension water walls and large water content.

Discontinuation notice

The Vitocrossal 300 CT3 boiler series has been discontinued in Canada. If you are looking to purchase a new commercial gas-fired boiler, please consider the Vitocrossal 200 or Vitocrossal 300 CA3 series.


Built to last

The Vitocrossal 300 is constructed using only the highest quality materials. The Inox-Crossal vertical heat exchanger surface is made of high-grade SA 240-316 Ti stainless steel - ideal for condensing applications.

Corrosive condensate simply drains downward off the smooth surfaces, effectively self-cleaning the heat exchanger and extending the operational life of the boiler, while reducing maintenance costs.

Product details


Rated input
638 to 3361 MBH - 187 to 985 kW
Combustion efficiency
Up to 98.3%
Natural gas, propane gas
Application range
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For apartment buildings, commercial applications and district heating, new buildings and retrofits.
DHW heating
Additional DHW tank(s) required, for a high level of DHW convenience
Limited 8 year commercial warranty
Additional features
Multi-boiler installation up to 13,444 MBH (3,940 kW) with up to 4 boilers.
Cutaway view


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A perfect match – System technology

"The whole is greater than the sum of its parts." According to this philosophy, Viessmann does not just make individual heating equipment components that meet the high Viessmann standards for quality, reliability and effectiveness. Rather, all products are part of a matching concept, where all components complement one another. Only the perfect interaction of system integrated components draws out the maximum potential of our innovative leading technology.

Viessmann system technology includes everything you need for a reliable and economical heating system. The Vitotronic control unit with remote control, the powerful Vitocell DHW tanks for best DHW convenience, to high-quality solar thermal systems for cost-saving heating.

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