Answering your heat pump questions

Answering your heat pump questions

Heat pumps have long been identified as a renewable energy source that can contribute to our net zero ambitions. Professional Builder puts the question to Stuart McWhinnie of Grant UK on the technology. 

PB: Can you provide some insight into the potential for heat pumps in the UK?

SW: At present, emissions from buildings make up 20% of the UK total, of which 78% of this figure is down to home heating appliances. The government has set out some ambitious plans on the route to net zero, and one of those is the phasing out of new and replacement fossil fuel boilers. As a result, heat pumps will have a major role to play in decarbonising home heating.

In 2021, approximately 55,000 heat pump installations were installed, but the target by 2028 is 600,000, which would make the UK one of the largest markets in Europe for heat pumps by the end of the decade.

PB: What about the new build sector?

SW: Absolutely. The Future Homes Standard – which the government is still committed to – means new builds from 2025 onwards will have some form of low carbon technology installed. 230,000 new builds were registered in 2021 but the target is 300,000 a year in England alone by the mid-2020s. So, coupled with the fact that these homes will be highly insulated, the ideal heating solution will be a renewable technology such as a heat pump.

PB: Could you tell us about some of the financial help that’s available?

SW:Through the Boiler Upgrade Scheme, a grant of £7,500 is on offer to contribute towards a heat pump installation. It is important to note that these funds are available to the homeowner and contain strict criteria for a successful application. The property must have a current EPC with no outstanding recommendations for wall or loft insulation, for example, and the company who installs the air source heat pump must be MCS registered. If the property is a new build, then it has to be shown that the build was financed by the homeowner and not the developer – i.e. it has to be a self-build.

There is also zero VAT on energy saving appliances until 31st March 2027. At present, there is an estimated cost of installing a system between £3,000 and £8,000.

Further information on the Boiler Upgrade Scheme eligibility can be found at

PB: Clearly there’s a big business opportunity here for tradespeople with the right skillset, but what would they have to do to become certified and competent in installing heat pumps?  

SW: The Microgeneration Certification Scheme (MCS) allows installers to prove their competency. This industry-led quality assurance initiative demonstrates to your customers that you can install and design to the expected level of quality.

It’s also worth considering specific product training from a manufacturer, and Grant UK does run a heat pump course at our state-of-the-art training centre at our UK headquarters in Swindon. In addition, we offer offsite training at merchant outlets and training colleges. There’s an eLearning Academy available online and we have engineers in the field who can visit individual projects and give advice on installation and commissioning.

Grant Training Academy

PB: What other benefits are there to being a Grant UK customer?

SW: Our regular customers can sign up for our G1 scheme, which is specifically tailored to our installer base. The scheme is designed to equip our customers with all the essential knowledge required to fit our products to the highest standards expected. A G1 installer can offer a 7-year guarantee on heat pump installations, for instance.

PB: When they are out in the field and they’re certified and competent, what would be some of the key factors tradespeople need to take into account for a successful heat pump installation?

SW: The key to a successful heat pump installation is the planning stage of the project. Air source heat pumps are termed as low temperature heating appliances, and they operate very differently to conventional heating systems. As a consequence, an in-depth heat loss calculation carried out to EN 12831 standard that will consider the fabric of the property and its U-values is crucial. Ventilation is also an important factor, with the external and internal temperatures that the system will be expected to operate undertaken into consideration. Once that calculation has been carried out, the planning of the pipe runs and the heat emitters can take place and sized accordingly.

When we consider the installation of the heat pump itself, where it is to be sited is important. For an air source heat pump a south facing aspect is preferable, whilst it will equally need to satisfy planning development rights and sound calculations. There are several other installation points that must be satisfied, such as power cable sizing, and soak away requirements. All that may sound daunting, but Grant UK will be on hand to help, not just with training, but in the design, and subsequent support.

Once installed and commissioned correctly you must ensure that a comprehensive handover to the end user or customer is carried out. Finally, annual servicing should be undertaken to ensure the best on-going performance.

PB: Can you give us an overview of what’s in the Grant UK heat pump range?

SW: At present, we have four units in the range from the 6kW Aerona³ R32 up to the 17kW R32 model. It is a common belief that heat pumps are noisy in operation but one of the key features of the Grant UK products are lower sound levels. Indeed, the Aerona³13kW and 17kW heat pumps both benefit from the internationally recognised Quiet Mark award.There’s also a hybrid available, which is one of our oil boilers combined with our Aerona³ 17kW heat pump.

Our Aerona³ air source heat pumps are termed asmonobloc units with a totally self-contained refrigeration circuit. That means they do not require the skills of an F-Gas registered engineer to set up and commission. The R32 refrigerant conveys heat energy efficiently, safely and cost effectively and has a low global warming potential compared with traditional refrigerants, with an ozone depletion potential of zero. Every model is compact, and highly efficient, even when external temperatures are low, whilst the controls are easy for the customer to navigate.

For further information on Grant UK range of heat pumps and the training on offer visit

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