Heat pump and low-loss header are a winning combination

A Grant Aerona³ air source heat pump has been installed as part of a new heating system for a bungalow which has been refurbished in Kent. Alongside the heat pump, a Grant low-loss header has also been fitted which is designed to support the efficient, reliable operation of the Aerona³.

The Project

• Property: 3-bedroom bungalow 
• Heat Source: air source heat pump
• Products installed: Grant Aerona³ 17kW air source heat pump , Grant 250L hot water cylinder and Grant low-loss header

In May 2022, the renovation of a bungalow in Petts Wood, Kent was completed. The project involved the complete refurbishment of the 3 bedroom property which included new interiors for all the rooms, a new kitchen and bathroom, as well as reducing the heat loss from the bungalow with cavity wall insulation and loft insulation fitted throughout. A gas central heating system previously heated the home and both the gas boiler and old radiators were removed making way for a new, more sustainable heating system.

Why the homeowners chose renewable heating

The homeowners wanted a renewable solution to fulfil their heating and hot water demand so they discussed the available options with their local G1 installer, NCC Southeast Ltd. After completing a thorough heat loss calculation for the property and assessing the requirements for the two people occupying the bungalow, NCC Southeast Ltd specified a new system comprising of an Aerona³ 17kW air source heat pump, a Grant 250ltr hot water cylinder, a low-loss header, an underfloor heating system totaling 168m² as well as a solar PV system.

“We specified a 17kW heat pump because, while it is oversized for the property’s current size, the homeowners are extending the bungalow next year so the larger output will fulfil this increased space heating demand in a few months’ time,” explains Neil Cornes, the installing engineer. “The heat pump supplies two manifolds which are controlling the underfloor heating system which has been laid throughout the property. We have also installed a boost system and the solar PV system will provide much of the electricity demand needed to run the heat pump, helping this property to be even more sustainable.”

Grant heat pumps and the benefits of a low loss header

The Grant Aerona³ heat pump range, which won Heat Pump Product of the Year 2022 at the National Heat Pump & ACR Awards, comprises of four models with outputs from 6kW up to 17kW. The 17kW model installed at this property is a twin fan unit which has an A+++ ErP energy rating as well as operating with low noise levels. Alongside the heat pump, NCC Southeast Ltd also fitted Grant’s combined low-loss header/volumiser which is creating hydraulic separation, separating the heat pump from the rest of the system and helping to maintain a correct flow rate through the heat pump unit.

Some of the benefits of installing the Grant combined low-loss header/volumiser include:

• Helps to maintain a correct flow rate through the heat pump unit
• Supports the heat pump to maintain the target flow temperature
• Can provide a suitable volume of system water (11.5 litres).

The diagram below shows the connections for the low-loss header/volumiser:

“Installing a low-loss header and using it for hydraulic separation is our preferred method when installing a heat pump system,” continues Neil. “It does involve a bit more planning during the early phase of an installation but the benefits it delivers are worth this extra time. Provided space inside a property permits, we fit a low-loss header but when this is not possible, Grant’s external volumiser serves a system well when space is limited.”

Financial support for heat pump installation

The homeowners made use of the Boiler Upgrade Scheme, claiming a voucher for £5,000 to go towards the installation costs. “NCC Southeast Ltd have been MCS certified for over seventeen years,” explains Neil. “We completed lots of installations through the Domestic RHI Scheme so we are very familiar with the processes involved in Government funding initiatives. Applying for and redeeming the Boiler Upgrade Scheme vouchers does involve more paperwork but the processes were smooth running and our client has benefitted from the grant to help them swap from a gas boiler to a heat pump.”

What is the BUS?

BUS is the Boiler Upgrade Scheme, a Government funded scheme available to eligible households in England and Wales. Through the BUS, homeowners who swap their fossil fuel boiler for an air source heat pump can claim a grant towards the installation costs. The Scheme first opened in 2022, when up to £5,000 was available for households to claim. Since then, the funding available through BUS has been increased and households can now claim up to £7,500 towards the cost of a heat pump installation when they replace their fossil fuel boiler, such as a gas or oil boiler. Please read our blog to learn more about the Boiler Upgrade Scheme (BUS).

Heat pump installation feedback

The Grant Aerona³ heat pump is working well for this bungalow and the end-users are pleased with their greener heating system. “We are using this particular installation as a template to share with our other clients who are interested in a renewable heating system,” concludes Neil. “The system is performing efficiently and, aside from regular visual checks of the heat pump and our annual service, it is low maintenance so the homeowners should enjoy many years of renewable home heating.”

Learn more about Grant package heating solutions

Here at Grant UK, we supply a comprehensive range of efficient heating products – please follow the links below to learn more about Grant’s renewable heating systems:

• Discover more about the Aerona³ and Aerona 290 air-to-water heat pumps
• View Grant UK’s range of hot water cylinders
• Read about Grant’s other renewable heating products, including solar thermal and underfloor heating systems.

(This case study was originally published on 25th July 2022 and updated on 27th January 2026.)