Get Paid for
Going Green

The Boiler Upgrade Scheme (BUS) launched in 2022 to support low-carbon heating systems. It offers grants to help cover the cost of installation. 

CLICK HERE FOR A BUDGET ESTIMATE >

Save on bills, reduce emissions, claim your grant

Get a low-carbon heating system that works for your home – and your wallet. Evergreen can help you access available funding, reduce your bills and move away from fossil fuels.

Note: You and your property must meet all the eligibility criteria, and there is a limited number of vouchers per year. We will do our best to secure any funding available.

GET STARTED TODAY >

Air Source Heat Pumps

Frequently Asked Questions

What is an air source heat pump and how does it work?

An air source heat pump is a low-carbon heating system that transfers heat from the outside air into your home. Even when it’s cold outside, the system can extract enough heat to warm your home and satisfy your hot water needs. It works using a refrigeration cycle, much like a fridge in reverse. The pump draws in outdoor air, extracts the heat, and compresses it to a higher temperature, which is then used for heating through radiators, underfloor systems and hot water cylinders. These systems are designed to work efficiently all year round.

How effective is an air source heat pump in the UK climate?

Air source heat pumps are highly effective in the UK climate. They are designed to work efficiently even in temperatures as low as -20°C, which is well below the average winter temperature in the South West. Since they extract heat from the air, (heat which is always present to some degree), they can provide consistent performance throughout the year. Many modern systems are equipped with inverter technology that adjusts the output to suit changing temperatures, helping to maintain a comfortable indoor temperature, while working efficiently and cost effectively.

How much does it cost to install an air source heat pump?

The cost of installing an air source heat pump typically ranges from £8,000 to £14,000, depending on the size of your property, the complexity of the system, and the existing infrastructure. The price includes the pump unit itself, the hot water cylinder, and all necessary installation work. Thanks to the Boiler Upgrade Scheme, eligible homeowners can receive a government grant of £7,500 towards the cost, making this a much more accessible option for many households. Evergreen handles the entire installation process and supports customers through the grant application, so there are no surprises along the way.

What is the Boiler Upgrade Scheme and how do I qualify?

The Boiler Upgrade Scheme (BUS) is a government initiative that provides financial support for the installation of low-carbon heating systems. Homeowners and landlords in England and Wales can apply for a £7,500 grant when installing an air source or ground source heat pump. To qualify, your property must have a valid Energy Performance Certificate (EPC).If your home is exempt from the insulation requirements due to its construction or other listed building restrictions, you may still be eligible. Evergreen is a registered installer under the Boiler Upgrade Scheme (BUS) and will guide you through every step of the process.

How much will I save on my energy bills with an air source heat pump?

An air source heat pump can significantly reduce your heating bills, especially if you’re currently using oil, LPG, or direct electric-only heating. They are highly efficient, often producing four times more heat than the electricity they consume. Actual savings depend on the energy performance of your home, your current fuel type, and how the system is used day-to-day. For many homes, the long-term savings can be substantial, particularly when combined with other renewable technologies such as solar PV.

Do I need planning permission to install an air source heat pump?

In most cases, you will not need planning permission to install an air source heat pump. The rules in England were relaxed on 29th May 2025. The installation of a heat pump is usually considered permitted development, provided certain conditions are met. It is still worth checking though. If you live in a listed building, conservation area, or national park, you may need to apply for permission. 

Where will the system be installed?

The main outdoor unit is usually placed near an exterior wall of your property, ideally on a flat, level surface such as a concrete slab or path. It should be positioned in an area with good airflow to maximise efficiency. Inside the property, a hot water cylinder will be installed – typically in a utility room, airing cupboard, or similar space – along with the system controls. Evergreen designs each system layout to suit the specific requirements of your home and ensures that everything is clearly explained before work begins.

Will an air source heat pump heat my whole house?

Yes, a properly sized and installed air source heat pump will provide space heating and hot water for your entire home. The key is to match the system’s capacity to your property’s heat demand. Evergreen conducts detailed heat-loss calculations to ensure the chosen system is suitable. Air source heat pumps work well with both underfloor heating and radiators, though older radiators may need upgrading to work efficiently with the lower flow temperatures produced by heat pumps.

Are air source heat pumps noisy?

Modern air source heat pumps are built with noise reduction in mind. Systems from manufacturers like Samsung and Mitsubishi have been engineered to meet strict noise level standards, making them suitable for domestic use without causing disruption. The outdoor unit produces a steady hum during operation, similar in volume to a fridge, and is quieter than most oil or gas boilers. Evergreen installs ASHPs in locations that minimise sound impact, and all installations comply with planning guidelines for residential noise.

What kind of maintenance is required?

Air source heat pumps are reliable and require only minimal maintenance. An annual service is recommended to ensure the system runs efficiently and to check things like system pressure, filters, and electrical components. Homeowners should also keep the outdoor unit clear of leaves or debris to maintain airflow. Regular servicing helps to extend the life of the system and keeps your warranty valid. Evergreen offers ongoing support and servicing options for all customers after installation.

How long does an air source heat pump last?

A well-maintained air source heat pump can last between 15 and 20 years, with many continuing to perform efficiently beyond that. Key components like the compressor are built to high standards and tested for durability. Evergreen installs systems from trusted manufacturers with strong performance records and provides guidance on how to keep your system in good condition throughout its lifespan.

Why choose Evergreen for your installation?

Evergreen has been installing renewable technolgies in Dorset, Devon and Somerset since 2011. The team is MCS-certified, experienced, and handles every stage of the process in-house – from survey and design to installation and aftercare. Evergreen works with leading manufacturers, including Samsung and Mitsubishi, ensuring high-quality products and excellent support. The company’s local knowledge, commitment to customer service, and strong track record make it a trusted partner for homeowners looking to switch to low-carbon heating.

Will I need to upgrade my radiators or heating system?

Air source heat pumps operate at lower temperatures than traditional gas or oil boilers, so they require radiators or underfloor heating systems that can distribute heat effectively at these lower flow temperatures. In many cases, existing radiators may be suitable, but they may need to be larger or upgraded for optimal performance. Evergreen will carry out a detailed heat-loss assessment of your home and advise whether any upgrades are required to ensure the system runs efficiently and keeps your home comfortable.

Can I combine an air source heat pump with solar panels?

Yes, air source heat pumps can work very effectively alongside solar photovoltaic (PV) systems. Solar panels generate electricity during the day, which can help power your heat pump and reduce your reliance on the grid. This combination increases the overall efficiency and sustainability of your home heating system. While the two systems are independent of each other, using them together is a smart way to lower energy costs and make full use of renewable energy sources on site.

How long does installation take?

Installation of an air source heat pump system typically takes between 3 and 5 days, depending on the size of the property and the complexity of the system. This includes the placement of the outdoor unit, installation of the hot water cylinder and system controls, and any necessary adjustments to pipework or radiators. Evergreen manages all aspects of the installation in-house, which allows for a smooth and efficient process with minimal disruption to your home.

Got another question? Get in touch