In this four-part series, PHPI and Grant UK team up to bring you a whole house renewable heating project, from start to finish. In part four we take a step-by-step look at the heat pump installation and handover.

It’s time for G1 installer Jake and his team to fit the Grant Aerona³ air source heat pump and prepare to hand over the installation to homeowner Helen and her family.

“The renovation project gave us the opportunity to completely transform our heating system, moving away from a fossil fuel and going green with a new heat pump,” explains Helen.

“Air source heat pump technology was completely new to us when we first started exploring the options available to us with our heating. Grant UK’s representatives talked us through the benefits of this renewable heating solution, answering our queries and helping us to understand how a heat pump could sustainably meet our heating and hot water requirements.”

The Aerona³ R32 air source heat pumps are Grant’s greenest and most efficient generation of heat pump technology. Compact in size and highly efficient, the Aerona³ heat pumps provide homeowners with a renewable solution to fulfil their heating and hot water requirements. Using the more environmentally friendly R32 refrigerant, an Aerona³ heat pump achieves high performances to effectively keep properties warm while also helping households to lower their dependency on fossil fuels.

The installation
It is important to remember that a full room by room heat loss calculation had been carried out as part of the G-Cert Scheme process which determined the heat pump required to meet the design conditions for this property. The heat emitters and pipework were also sized to deliver the required heat output at the lower heat pump system flow temperature.

Anti-vibration feet are put into position on a flat level base – in this case the Selman’s had a new patio laid in readiness.

Jake and Matt bolt the 13kW heat pump to the feet.

Jake plumbs the Grant Monowave 300ltr high performance cylinder in the garage. This has adequate hot water storage for the family’s needs and a larger indirect coil than a standard cylinder to effectively provide hot water with the lower flow temperature from the heat pump.

Matt makes the heat pump plumbing connections between the unit and the cylinder.

Both the electrical supply and controller for the heat pump, along with the system heating controls, are wired and tested by the electrician.

Matt lags the heat pump pipework to protect against heat loss.

Jake lags the pipework in the garage.

Grant’s senior field engineer John arrives to assist with system set up and commissioning.

John runs through the heat pump parameters on the controller with Jake and checks the heating system controls are set to achieve the required system performance. The circulating pump output is also set, and the emitter circuit is balanced.

John reviews the G-Cert checklist and signs off the installation.


Finally a full handover with the homeowner is provided to ensure they understand the system and the importance of having it serviced on an annual basis.


The job is complete!

“Our heating and hot water demand is now being efficiently fulfilled by an air source heat pump which is working effectively alongside the complementary technologies also supplied from Grant UK,” continues Helen.

“It was useful to have John, Grant UK’s Senior Field Service Engineer, return to site to complete the commissioning and handover of the system with our installer. He explained the heat pump controls – highlighting how important it is not to tinker with them – and it was useful having John on hand to run through the important sections of the large but very comprehensive handover file.”

About the house
The Grant House is a four-bedroom semi-detached property in Wiltshire which is undergoing a complete heating system upgrade as part of a wider renovation project. In addition to building a large extension off the side of the property, the owners are upgrading their home’s heating system, changing from a gas boiler to a renewable system thanks to the installation of a Grant Aerona³ air source heat pump.

About Grant UK
Grant UK has been designing and manufacturing reliable and easy to install heating products for over four decades. It’s product portfolio includes award winning Vortex oil fired condensing boilers and the latest renewable technologies like solar thermal, air source heat pumps, cylinders and condensing biomass (wood pellet) boilers, and an oil boiler/air source heat pump hybrid. The company also has a growing range of heat emitters from wet underfloor heating systems through to fan convectors and aluminium radiators.

The whole Grant House at your fingertips
You can check out the whole Grant House series and access knowledge, training and support at

Related posts