New Viessmann heat pumps for the easy replacement of boilers

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. This means that in some cases, for the Vitocal 150-A, the existing hot water cylinder can be retained, depending on its coil size, desired store temperature, insulation level and mechanical integrity. 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, existing radiators may also be retained, depending on the heat loss from the house, which is a calculation the installer is required to undertake.

Both heat pumps use the same control platform as Viessmann’s boilers so that they are compatible with the rest of Viessmann’s product range. And both integrate previously separate system elements in the indoor unit (IDU), reducing installation time by 90 minutes. 

Both models are extremely quiet in operation thanks to Viessmann’s Super Silent Design. 

Space saving design

The Vitocal 150-A and 151-A are also even more space-saving compared to other heat pumps on the market, as they take up 60% less space in the home, due to the unique and innovative Viessmann OptiPerform, incorporating the Hydro AutoControl feature. The buffer tank, expansion vessel, and overflow valve – components which usually have to be installed and connected separately – are now integrated in the IDU. 

Locating the defrost buffer inside the IDU also ensures that the heat pump never fails to start, regardless of system temperature. For future-proofing and to ensure very low global warming potential (GWP), the system uses R290 (propane) refrigerant, one of the most climate-friendly and cost-effective available with a GWP of less than 1!  

With a COP (Coefficient of Performance) of 4.9-5.0 (according to EN 14511 for A7/W35 and depending on the model), the new heat pumps generate up to five times the usable heat for heating and hot water from one kilowatt hour of electricity and heat from the outside air.  

Commissioning these new heat pumps is also made easy for installers, by using the ViGuide app. The patented Hydro AutoControl hydraulic function assists reliable integration into existing heating systems. The Service Link integrated internet connection allows for remote updates with a fast connection, even if there is domestic internet disruption and the unit is not connected to the internet. 

All Viessmann products and digital services, for both installers and end-users, are networked within its new One Base software platform. This seamlessly connects the new heat pumps with other system components such as the company’s Vitovolt solar PV system, as well as the ViCare customer app and the service tool, ViGuide, for the installer. 

Viessmann’s Marketing Director, Darren McMahon, said: “When the time comes for homeowners to replace their boilers, more are now looking for renewable alternatives. The Vitocal 150-A and 151-A air source heat pumps help answer this growing need. The end-user gets an efficient, environmentally-friendly solution that can deliver heat like a boiler; the engineer gets a unit that’s much easier and faster to install. Having fewer pieces of equipment has cut the time needed for installation by 90 minutes as well as taking up less space from your home.”  

The Vitocal 150-A and 151-A go on sale in the UK in May. Installation training courses for these new products are available now through the Viessmann Academy. 

April 26th 2022, updated June 27th.