Homeowners Professionals

Viessmann launches lower output Vitocal 150/151-A air source heat pumps

Three new variants expand Viessmann’s top-selling ASHP range, which are perfectly sized for home modernisation boiler replacements.

TELFORD – July 4th 2023 – Viessmann has added three new, lower output variants to its popular Vitocal 150-A/151-A domestic air source heat pump range. The 4, 6 and 8 kW models complement the existing 10, 13 and 16 kW heat pumps launched in 2022, providing a wider choice of outputs and allowing heating modernisation projects suited to a broader range of properties.

All Vitocal 150-A/151-A models provide both heating and cooling and are available to purchase for connection to single-phase electricity supply, with three phase models also available for the 10 to 16 kW variants. They are notable for their environmental credentials using R290 natural propane refrigerant, which is one of the most climate-friendly and cost-effective available with a Global Warming Potential (GWP) of only 0.02.

Both the wall-mounted Vitocal 150-A and the floor-standing Vitocal 151-A with integral 190-litre DHW cylinder, have a maximum flow temperature of 70 °C, providing customers with superior hot water comfort. If the existing cylinder is not suitable, then the Vitocal 151-A with its integral cylinder is a perfect replacement.    

Subject to the system design requirements and seasonalised efficiency calculations, it may be possible to retain existing radiators, depending on the heat loss from the house, which is a calculation the installer is required to undertake.


Both models are extremely quiet in operation thanks to Viessmann’s Super Silent Design, for example the 6 kW outdoor unit has a sound pressure level of only 33.5 dB(A) at a distance of three metres when installed against one wall in standard heating mode. The One Base control platform features an Integrated Energy Management System, which provides customers transparency in energy consumption and costs.

The single-fan outdoor unit of the new models is half the height of its 10, 13 and 16 kW counterparts, standing at just 800 mm high.

“Vitocal 150-A and 151-A heat pumps with natural propane refrigerant are highly efficient at the full range of flow temperatures and extremely quiet,” explains Darren McMahon, Viessmann Marketing Director.  

“The arrival of the 4, 6 and 8 kW models provides our installers with added flexibility to select the appropriately-sized product for homes with low heat losses, such as smaller or newer homes, or perhaps whole house retrofits. In the case of a whole house retrofit then the One Base control platform opens up the possibility for additional technologies to be integrated into the system such as PV, battery storage, MVHR and EV chargers. By the end of 2024, Viessmann will have launched all of these elements and all will be visible to the homeowner within the ViCare app, as well as to the installer via the ViGuide app, which offers remote monitoring, maintenance and troubleshooting.”  

About Viessmann Ltd.

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 climate (heating, water and air quality) and renewable energy solutions. Creating living spaces for generations to come – this is the responsibility that we take on every day together with our (trade) partners.

Press Enquiries

Claire Dumbreck, Propel Technology, claire@propel-technology.com, 07768 773857.


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