Air source heat pump FAQs

A typical installed air source heat pump costs £8,000 to £16,000 before the grant, depending on the size of your home and whether radiators or a hot water cylinder need replacing. After the £7,500 BUS grant, most homes pay between £1,500 and £8,000.

The Boiler Upgrade Scheme (BUS) gives £7,500 off the cost of an air source heat pump in England and Wales. Your MCS-certified installer applies for it and deducts it from your quote, so you never pay the full price up front.

You must own the property (homeowners, landlords and small businesses all qualify), live in England or Wales, be replacing a fossil fuel system such as gas, oil or LPG (or direct electric heating), and have a valid Energy Performance Certificate. Most new-build homes are not eligible, though custom self-builds can be.

For most homes coming off oil, LPG or old electric heating, yes: running costs usually fall and the £7,500 grant covers much of the installation. Against mains gas the savings are smaller and depend on your tariff and how well the system is designed, but you cut your heating carbon emissions by around 70% or more.

Modern units are quiet: typically 40 to 55 dB at one metre, similar to a fridge or a quiet conversation. Your installer must complete an MCS noise assessment to confirm the unit meets permitted development limits at your neighbour's nearest window.

Yes. Air source heat pumps extract heat from outside air down to around -20°C and are used widely across Scandinavia. Efficiency dips on the coldest days, which is why a correctly sized system matters, but a well-designed install keeps a UK home warm all winter.

Usually not. In England and Wales most air source heat pumps are permitted development, provided the unit meets size, siting and MCS noise rules. Listed buildings, flats and some conservation areas may need consent, and your installer will check this during the survey.

Most homes are fitted in 2 to 4 days. That includes mounting the outdoor unit, fitting a hot water cylinder, connecting pipework and upgrading any radiators that are too small. You'll have hot water and heating back at the end of each working day wherever possible.

Around 20 years with an annual service, compared with 10 to 15 years for a typical gas boiler. Most manufacturers offer 7 to 10 year warranties when the unit is fitted by an approved installer.

Not always. Heat pumps run at lower flow temperatures than boilers, so some radiators may need to be upsized to keep each room warm. Your installer works this out with a room-by-room heat loss calculation and includes any changes in your quote.

No. Heat pumps installed in homes in Great Britain are zero-rated for VAT until 31 March 2027, which is already reflected in the prices you'll be quoted.

The Boiler Upgrade Scheme covers England and Wales. In Scotland, Home Energy Scotland offers a grant of up to £7,500 (plus a rural uplift) and an optional interest-free loan. Northern Ireland does not currently have an equivalent heat pump grant.

An adviser will call you, usually within one working day, to confirm a few details. An MCS-certified installer then carries out a survey and heat loss calculation and gives you a fixed quote with the £7,500 grant already deducted.

Yes. Checking your eligibility and getting a quote costs nothing and there's no obligation to go ahead. We're paid by our installer partners, not by you.

Yes, for an air-to-water heat pump. It heats water into a stored cylinder, typically 150 to 300 litres for a family home. If you currently have a combi boiler, your installer will find a suitable space.

To claim the £7,500 grant, the heat pump must replace your fossil fuel system and meet your full heating and hot water needs. Hybrid systems that keep a gas boiler are not eligible.

An annual service is recommended and is often a condition of the manufacturer's warranty. It's quick: checking refrigerant pressures, cleaning filters and the outdoor coil, and reviewing controls.

Often, yes. Many radiators are already big enough. Your installer's heat loss calculation will show which, if any, need upgrading to keep each room warm at the heat pump's lower flow temperature.