Summary

Air source heat pumps are a type of low-carbon central heating that runs on electricity. They work by extracting heat from the outside air, amplifying it and using it to provide heat and hot water to homes. 

For every unit of electricity used, a heat pump can produce around three to four units of heat, making them very energy efficient.

Air source heat pumps are the most common type of heat pump because they are generally cheaper and easier to install than other heat pump systems.

Installation costs and financial support

The typical cost of installing an air source heat pump is £7,500 to £15,000, depending on the size of the property and the existing heating system. Some homes may need additional work, such as upgrading radiators or pipework.

The Boiler Upgrade Scheme provides a £7,500 grant towards the cost of an air source heat pump. The grant is paid directly to the installer and reduces the upfront cost.

Running costs

The running costs for heat pumps vary, depending on how well insulated the home is. 

For a well insulated home, the yearly running costs will usually be the same as or slightly cheaper than a gas boiler. For a less well insulated home, a heat pump could be more expensive to run than gas. 

But air source heat pumps can be much cheaper to run than night storage heaters, bottled gas, electric boilers or plug-in heaters. 

Future running costs will depend heavily on electricity prices and home insulation standards.

Is the home suitable?

Most homes can be fitted with an air source heat pump, but some are more suitable than others. Key requirements for the home include:

• An electricity supply
• Space outside for the heat pump unit, usually on an external wall
• Space indoors for a hot water cylinder. If the home currently has a combi boiler, more space will be needed.

Air source heat pumps work best in homes that are well insulated and draught proofed. Improving insulation before installing the heat pump helps the system work more efficiently and keeps running costs down.

Installation

The heat pumps must be installed by a qualified specialist installer.

Before installation, the installer will assess how well the home retains heat. They will calculate the right size for the new system and check whether any upgrades (such as larger radiators) are needed.

The disruption from the installation is similar to having a new central heating system fitted.

Comfort and heating controls

Air source heat pumps work differently to traditional boilers. They provide a steady background heat rather than quick bursts of hot air. Once set, the system maintains a consistent indoor temperature.

They are well suited to people who are at home during the day or who prefer simple, automatic heating controls.

The unit makes a noise similar to a fridge-freezer. Installers will take this into account when choosing a suitable location outside the house. 

More information

Find out about the Boiler Upgrade Scheme

Clean Energy Campaign heat pump advice

Centre for Sustainable Energy heat pump Q&A

Energy Saving Trust heat pump advice