Viessmannstr. 1
DE 35108 Allendorf
Products and innovations

Vitocal 250-A monoblock air source heat pump

Vitocal 250-A monoblock air source heat pump

The test winner among air source heat pumps impresses with its whisper-quiet operation, convenient control and high energy efficiency that helps to conserve valuable resources and save costs.

The Vitocal 250-A is one of the quietest appliances of its kind: thanks to its low sound emissions of 30 dB(A) at a distance of four metre, it is barely audible.

The powerful outdoor units in monoblock design (A16, A19) are particularly suitable for heating system modernization projects. As the heating output has been significantly increased for particularly low outside temperatures (down to minus 15 degree), larger buildings in colder regions can also be equipped with the new Vitocal 250-A series.

The compact indoor unit is based on the tried and tested Vitocal 250-A series. The patented Hydro AutoControl® hydraulic system ensures reliable and highly efficient operation over the entire service life, making installation as easy as replacing a gas condensing boiler.

Stand events

Explainer presentations on our product solutions

Hall 3 Stand 3A11
03/19/2024 09:00 - 17:00
03/20/2024 09:00 - 17:00
03/21/2024 09:00 - 17:00
03/22/2024 09:00 - 15:00

Entertaining, daily explainers in the stand forum

Product range

Viessmann's integrated range of solutions

Viessmann's integrated range of solutions

Viessmann is a leading provider of climate solutions for all living spaces. Viessmann's integrated range of solutions makes it possible to seamlessly connect products and systems via digital platforms with services for climate (heating, cooling & air quality) and refrigeration solutions. A key component is connectivity: existing systems dating back to 2002 can be connected via the Vitoconnect internet interface. This means that the systems are upgradeable and can be controlled from anywhere at any time. All new appliances already feature the integrated Viessmann One Base electronic platform, which networks the products and systems of Viessmann's integrated range of solutions and connects them with digital services. This creates comprehensive and seamlessly linked climate and energy solutions that work together optimally thanks to integrated Viessmann Energy Management.

Product range

Vitodens gas condensing boilers 100 % H2 ready

Vitodens gas condensing boilers 100 % H2 ready

According to the new German Buildings Energy Act (GEG), which came into force on 1 January 2024, new H2 100 % ready gas appliances can be installed without meeting the 65 % RE (renewable energy) requirement if the building in question is located in a yet to be designated hydrogen grid expansion area. Gas condensing boilers in the Vitodens 300/200 series from Viessmann manufactured from 1 January 2024 onwards can be converted for operation with 100 % hydrogen in accordance with the requirements of GEG Section 71k (Appendix B). The appliances will be converted using a conversion kit that can be efficiently installed during normal maintenance work. Certification of the gas condensing boilers in combination with the conversion kit takes place in accordance with the valid specifications of ZP 3100.100 and EN 15502. The conversion kits are expected to be available as standard from 1 January 2026.

Product range

Viessmann Invisible

Viessmann Invisible

Viessmann Invisible is the groundbreaking heating and ventilation solution that allows design freedom and optimum use of space. To achieve this, Viessmann combines a latest generation heat pump, a ventilation module, a DHW cylinder and all the accessories in one compact system, creating space for new room concepts. All components are concealed behind a slimline plumbing wall installation that is less than 30 centimetres deep. This can transform a utility room, which may previously have been full of various technical equipment, into an additional, usable living space. Side by side, corner arrangement or as a block: Viessmann Invisible can be sited in a range of different ways in newly built single-family houses of up to 200 m2. Thanks to standardised and factory-configured components, Viessmann Invisible is versatile and allows design freedom – from the floor plan of the building upwards.

Product range

Viessmann One Base

Viessmann One Base

Viessmann One Base is an intelligent electronic platform for controlling energy systems. For example, a Vitocal heat pump can be very easily supplemented with a Vitovolt photovoltaic system and a Vitocharge power storage unit. All users need for control is the free ViCare app, which already has Viessmann Energy Management integrated for efficient, resource-saving system operation. Trade partners also benefit from the intelligent platform: Viessmann One Base networks the products and systems in Viessmann's integrated range of solutions and links them with digital services. Be it a Vitocal heat pump, Vitodens gas condensing boiler, Vitoair ventilation system or Vitovolt photovoltaics – commissioning, maintenance, service and monitoring are taken care of using a single application, the ViGuide app.

Product range

Vitocal 250-A PRO air source heat pump

Vitocal 250-A PRO air source heat pump

With its variable output adjustment, the Vitocal 250-A PRO is a heating and cooling solution that can be tailored to individual project requirements in larger residential and commercial buildings and businesses. One appliance generates up to 38 kW of heating output. For larger outputs, a cascade of up to four appliances (up to 152 kW in total) is possible. Only one compact indoor unit is required for this. The weather-compensated heat pump control unit for space saving wall mounting can control up to three heating/cooling circuits with mixer and one heating water buffer cylinder. The Vitocontrol A PRO control unit (indoor unit) can be readily integrated into the building management system. This means that the heat pump system can be remotely controlled and its operation monitored from a central control centre. The system data can be controlled and called up from anywhere at any time via a standard BACnet IP or Modbus TCP/IP connection.


Product range

Vitocrossal 300, type CI3 gas condensing boiler

Vitocrossal 300, type CI3 gas condensing boiler

This new gas condensing boiler is a highly efficient solution for apartment buildings, commercial enterprises and local authorities. Eight output sizes from 80 to 640 kW and a function for cascade operation for an output of up to 5120 kW make it particularly flexible. The innovative Inox-Crossal heat exchanger made of high grade stainless steel enables a high power density with maximum reliability. With its handling width of just 75 cm, the Vitocrossal 300 CI3 is also recommended for modernisation projects in buildings where space is limited. It also stands out thanks to its very modest overall space requirement of just 0.75 to 1.07 m2 (80 to 640 kW). The MatriX cylinder burner with a modulation range of 1:10 offers clean combustion. The self-calibrating O2 sensor, which automatically adjusts the burner to different gas types, ensures consistently high combustion quality. To further reduce CO2 emissions, hydrogen blends of up to 20 % can be used alongside natural gas/LPG P.

Company news

SHK+E Essen 2024: innovative system solutions for heat and power supply

● Comprehensive energy systems for heat, cooling, ventilation and power
● Second focus on the extensive range of services for specialist partners
● Download the press release and complete press kit at:

Essen, Allendorf (Eder), 3/19/2024 – From March 19 to 22, 2024, Viessmann Deutschland GmbH will present its newest energy solutions at the SHK+E in Essen, Germany, (Hall 3 Stand 3A11) under the motto “Fully connected: electricity and heat in a single system”. Some of the products presented include combinations of heat pumps, photovoltaics, electricity storage systems and charging stations, which increase homeowners’ independence from public electricity supply while also relieving the load on the grid at peak load times. The pioneering Viessmann Invisible climate system that creates more space in the home and recently received the iF Design Award 2024 will also be on show.

A second focus this year will be placed on the wide range of assistance and support services that Viessmann provides for specialist partners to make their day-to-day work easier and more efficient. The information being offered will be rounded off by interesting short presentations on selected specialist topics, which will be held daily at the trade fair stand.

The most important new arrivals at a glance

● Vitocal 250-A: winner of the Stiftung Warentest heat pump test now available in new output sizes
The Vitocal 250-A heat pump for modernization projects (Type: AWO-E-AC 251.A10, rated output 2.6 to 9.7 kW at A-7/W35 based on EN 14511) was the winning product in a comparison conducted by Stiftung Warentest in October 2023. This year, additional output sizes (16 and 18.5 kW) expand the range of applications for Vitocal 250-A and 252-A heat pumps to buildings with larger heating loads.

● Vitocal 250-A PRO: air/water heat pumps for commercial use win the iF Gold Design Award 2024
The compact monobloc heat pump for larger residential buildings, commerce and commercial buildings heats, cools and produces hot water with flow temperatures of up to 70 °C. It has now been recognized for its outstanding design with the iF Gold Design Award 2024.

● Vitocal 262-A: hot water heat pump now with natural refrigerant R290
The new versions of the hot water heat pump now work with the natural refrigerant R290 and are compatible with the Viessmann One Base platform. This enables seamless communication with other components in Viessmann’s Integrated Solution Offering.

● Vitovolt 300-DG: new double-glass photovoltaic module with bifacial TOPCon cell technology
The new premium PV modules come in a double-glass design with bifacial N-type TOPCon cell technology and achieve outputs of up to 445 Wp. These models come with a performance warranty of up to 30 years and a product warranty of up to 25 years.

● Vitocharge VX3: modular electricity storage system can now be cascaded to up to 75 kWh
The Vitocharge VX3 hybrid electricity storage system is the centerpiece of every comprehensive system solution for heat and power. It can be cascaded to up to 75 kWh of battery capacity and has a maximum AC output of up to 45 kW, thus expanding the modular electricity storage system’s range of applications.

● Vitoair CT PRO: the latest ventilation system for smaller commercial applications
Some of the key strengths of the new Vitoair CT PRO are its above-average heat recovery rate of up to 84 percent (in accordance with DIN EN 308) using counter-flow
heat exchangers and its vertical air duct connectors that enable a very small footprint.

● Vitoair Valve: the new universal solution for supply and extract air
The new Vitoair Valve ventilation valves are designed for universal use and feature colored caps to help them blend seamlessly into even the most sophisticated living
space. The low installation depth of the valve housing makes it suitable for all standard forms of installation. The Vitoair Valve received the iF Design Award 2024 for its
attractive and elegant shape and for the use of high-quality materials that make it an eye-catcher in any room.

● Viessmann One Base: Integrate third-party systems with Solar-Log
The new Solar-Log Base Vi expands the integration of existing photovoltaic systems into an energy system under the Viessmann One Base electronics platform. It also now features a new EMS tool that supports specialist partners when selecting the necessary energy system products and displays the associated circuit diagrams.

● ViGuide: Digital tradesman tool with additional applications
The new ViGuide Business is specifically aimed at landlords, contractors and commercial system operators. The tool can be used to view systems at several locations
in a clearly organized manner and make basic settings online if required.

● ViGuide Planning: planning tool now includes the automatic transfer of heating loads and check for GEG conformity
The app enables joint project planning with access for sales, pre-sales and specialist partners on a single platform. ViGuide Planning now automatically transfers values from the heating load calculation to the system planning and checks compliance with the specifications of Germany’s Building Energy Act (GEG).

● ViParts: new app for easy ordering of spare parts
Spare parts found quickly. Exploded drawings and parts lists are displayed directly, and can be entered more quickly thanks to an optimized spare parts search function.

● Viessmann Home: Conserve valuable market partner capacity
Viessmann Home enables end customers to enjoy quick access to answers that cover frequently asked questions and to the Viessmann Climate Solutions Community, which helps them to find answers themselves instead of contacting their specialist partner. In doing so, Viessmann Climate Solutions helps to conserve the valuable capacities of its market partners.

● Heat Pump Protect: new all-risk insurance against theft and damage
Operators of Viessmann heat pumps who have insured their outdoor units with Heat Pump Protect can look to the future and enjoy peace of mind. The convenient solution includes not only protection against theft and vandalism but also damage from natural hazards such as storms, hail, lightning, flooding, damage caused by animals as well as operating faults.

● FörderProfi (Subsidy Pro): competent subsidy support with new features
FörderProfi (Subsidy Pro) is your reliable digital partner for applying for state subsidies for a new heating system. New features this year include the heating check and the inclusion of automatic flow balancing.

Follow this link to access the press kit including all detailed press releases:

Viessmann Climate Solutions
We are Viessmann Climate Solutions. Founded in 1917 as a heating technology manufacturer, today, as part of Carrier, we are a global leader in efficient and systems-based climate (heating, cooling, water and air quality) and renewable energy solutions for the residential and commercial sector.
Our integrated solution offering seamlessly connects products and systems via digital platforms and services to a holistic climate and energy solution, creating a safe and reliable environment for our users. All activities are based on our mission statement “Designing living spaces for generations to come.” This is the responsibility that guides us and our (trade) partners every day.

Company news

Innovative solutions for the perfect interaction of heat and power supply

Thinking in systems is necessary for a safe and climate-friendly heat and power supply of thefuture. Viessmann Deutschland GmbH will be showcasing innovative system solutions at SHK+E Essen trade fair from March 19 to 22, 2024 (Hall 3, Stand 3A11). A combination of heat pump, photovoltaic system, power storage unit and wallbox will be on display. Homeowners can use the self-generated electricity to not only operate their heat pump and charge their electric vehicle, but also to help relieve the burden on public power grids during peak load times.

Test winner with more performance

The Vitocal 250-A air/water heat pump is ideal as the central component of such system solutions. The winner of the Stiftung Warentest comparison from October 2023 will be available this year with additional output sizes of 16 and 18.5 kilowatts. This means that the heat pump, which achieves flow temperatures of up to 70 degrees Celsius, is also available for existing and new buildings with higher heating loads. The Vitocal 250-AH hybrid heat pump will also be presented with the new output sizes of 16 and 18.5 kilowatts.

New photovoltaic modules use solar energy from both sides

Complementing the heat pump with a photovoltaic system creates greater independence from electricity drawn from the grid, for example with the new Vitovolt 300-DG PV modules. As double glass modules with bifacial TOPCon cell technology, they utilize the incoming solar energy from both sides. This means that the same output can be achieved with fewer modules
as with standard modules.

Vitocharge VX3 power storage: Now cascadable for up to 75 kilowatt hours

At the heart of every system solution for heat and electricity is the new generation of the Vitocharge VX3 hybrid storage cylinder. The modular storage cylinder has up to three battery units with a storage capacity of 5 kilowatt hours each and can now also be cascaded with up to five units. Storage capacities of up to 75 kilowatt hours are then available, enough for the electricity requirements of large detached houses, apartment buildings and smaller businesses.

Smart system for maximum independence

The Viessmann One Base electronics platform ensures that all system components work seamlessly with each other and with digital services, such as the ViCare app for device operation and the ViGuide digital service tool. The integrated energy management system optimizes the interaction between the photovoltaic system and power storage unit with the heat pump as well as any existing wall box for charging an electric vehicle.

Company profile

We are Viessmann Climate Solutions. Founded in 1917 as a heating technology manufacturer, and now part of Carrier, today we are one of the world's leading providers of efficient and systemic climate (heating, water and air quality) and renewable energy solutions for the residential and commercial sector. 

Our integrated solution offering seamlessly connects products and systems via digital platforms and services to a holistic climate and energy solution, thus creating a safe and reliable feel-good climate for our users. All activities are driven by our company purpose, "We create living spaces for generations to come". This is the responsibility that we take on every day together with our (trade) partners.


The stand in the interactive hall overview

The stand in the interactive hall overview