An air source heat pump in the UK costs £8,000 to £14,000 after the £7,500 Boiler Upgrade Scheme grant, which runs until 31 March 2028.
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An air source heat pump (ASHP) extracts heat from outside air and uses it to warm your home and hot water.
It works on the same principle as a fridge in reverse. A refrigerant absorbs ambient heat from the air, even at temperatures as low as -15°C, then compresses it to a higher temperature and transfers it to your central heating system. The result is roughly 3 to 4 units of heat for every unit of electricity used, which is why heat pumps are described as 300-400% efficient. A modern gas boiler tops out at around 92%.
The UK installed around 60,000 heat pumps in 2024 according to MCS data, with installations growing roughly 50% year-on-year. The technology is mature, the supply chain is stable, and the Energy Saving Trust now treats ASHPs as the default low-carbon heating choice for most UK homes.
Two types exist: air-to-water (which feeds radiators and hot water cylinders, by far the most common in the UK) and air-to-air (which heats your home via fans, similar to air conditioning in reverse). When people say "heat pump" without qualification, they almost always mean air-to-water.
A full installation costs £14,000 to £21,000 before grants, or £8,000 to £14,000 after the £7,500 Boiler Upgrade Scheme grant.
The price depends on three things: the size of the unit (measured in kW output), whether your existing radiators and pipework need upgrading, and whether you need a new hot water cylinder. A typical three-bedroom semi needs a 7-9kW unit, which is the most common spec installed in the UK.
Boiler Upgrade Scheme grant available for air source heat pump installations until March 2028
The grant comes off your installer's invoice directly. You don't pay upfront and claim back. Your MCS-certified installer applies to Ofgem on your behalf, and the £7,500 is deducted from the quote before you sign anything.
For a fully ECO4-funded install (no cost at all), you need to be on qualifying benefits with an EPC rated D to G. The ECO4 scheme covers the full installation cost in those cases, though heat pumps are less commonly funded under ECO4 than boilers because the upgrade often requires extensive insulation work first.
Running costs average £900 to £1,400 a year for a three-bed home, depending on insulation quality and electricity tariff.
This is the question that derails most heat pump conversations. The honest answer: a well-installed heat pump in a properly insulated home runs cheaper than gas. A poorly installed heat pump in a draughty home runs more expensive. The variable isn't the technology, it's the property and the installer.
The maths: a heat pump with a Seasonal Coefficient of Performance (SCOP) of 3.5 uses 1 unit of electricity to produce 3.5 units of heat. At the April 2026 price cap of around 27p per kWh of electricity, that's an effective heat cost of 7.7p per kWh. Gas costs around 6.5p per kWh, but a 90% efficient boiler delivers effective heat at 7.2p per kWh. The numbers are close enough that insulation quality and tariff choice usually decide which is cheaper.
If you're on a standard electricity tariff, gas usually wins on running cost by a small margin. If you switch to a heat pump tariff like Octopus Cosy or OVO Heat Pump Plus, the heat pump usually wins by 15-25% because off-peak electricity drops to 12-15p per kWh.
The specialist heat pump tariffs are the deciding factor most buyers don't realise exists. They charge a higher peak rate but a much lower rate during 4-6 off-peak hours, which is when a well-controlled heat pump does most of its heating work via the thermal mass of your radiators and cylinder.
The Boiler Upgrade Scheme is open to most UK homeowners until 31 March 2028.
You own the property
Owner-occupiers, landlords and small businesses qualify. Tenants cannot apply directly, the landlord must apply.
Property has a valid EPC
The EPC must have no outstanding recommendations for loft insulation or cavity wall insulation. If your EPC flags either, you must complete those works first or get a new EPC issued.
You’re replacing fossil fuel heating
The grant applies whether you’re replacing gas, oil, LPG or electric. New-build properties don’t qualify because they’ve never had heating to replace.
England or Wales
BUS covers England and Wales only. Scotland has Home Energy Scotland loans and grants; Northern Ireland has separate schemes.
You use an MCS-certified installer
The installer applies for the grant on your behalf. You can’t self-apply. Check the installer’s MCS number on the official register before signing.
The eligibility checker confirms whether BUS, ECO4 or a local Warm Homes grant applies in 2 minutes.
The EPC requirement catches people out. If your last EPC (issued any time in the past 10 years) flagged "loft insulation could be improved" or "cavity wall insulation could be installed", BUS won't fund the heat pump until those measures are done or a new EPC is issued without the recommendations. The reason is simple: a heat pump in a leaky house runs inefficiently, which undermines the whole point of the subsidy.
A new EPC costs £60 to £120, our EPC ratings guide covers what assessors look for and how to improve your score before the heat pump survey.
Your situation
You own your home, EPC is C or above, no insulation recommendations
Best route
Boiler Upgrade Scheme (£7,500)Your situation
You receive Universal Credit, Pension Credit or other qualifying benefits
Best route
ECO4 (potentially fully funded)Your situation
Your household income is low but you don’t claim benefits
Best route
ECO4 Flex via your councilYour situation
You’re off the gas grid (oil, LPG, electric heating)
Best route
BUS plus prioritised council schemesYour situation
You’re a landlord with a rental property
Best route
From enquiry to working heat pump takes 8 to 14 weeks for most installations.
An MCS installer visits to measure heat loss, assess your radiators and check the proposed unit location. Survey is usually free.
The installer produces a room-by-room heat loss report. This determines the heat pump size and whether any radiators need upgrading.
Your installer applies to Ofgem with your EPC, property details and quote. Approval takes 2-3 weeks. The £7,500 is deducted from your invoice.
The single most important step is the heat loss calculation. A badly sized heat pump is the root cause of almost every "my heat pump doesn't work" complaint. Oversized units short-cycle and run inefficiently. Undersized units can't keep up in cold weather. A proper room-by-room calculation, not a rule-of-thumb estimate, is non-negotiable.
If an installer quotes without doing a heat loss calculation, walk away. The MCS standard MIS 3005 requires one, and any installer skipping it is cutting corners.
Most homes need at least some radiator upgrades, and the installer factors this into the quote.
Heat pumps run at lower flow temperatures than gas boilers, typically 45-55°C versus 65-75°C. To deliver the same heat output at a lower temperature, you need larger radiator surface area. In practice, this means around 30-50% of radiators in a typical UK home need replacing with larger units. The installer's heat loss survey identifies which ones.
Pipework is usually fine. Standard 15mm and 22mm copper pipework that's already in your house works for heat pumps in the vast majority of cases. The myth that heat pumps need a full microbore-to-22mm upgrade applies to maybe 5% of installations, usually older properties with very narrow original pipework.
The other component you'll need is a hot water cylinder if you don't already have one. Combi boiler homes don't have a cylinder, and a heat pump can't heat hot water on-demand the way a combi does. Budget around £600-£1,200 for a heat pump-compatible cylinder; this is included in the headline install cost.
Very few UK homes are genuinely unsuitable, but a handful of property types make heat pumps harder.
When a heat pump might not be the right call
The following situations don’t make a heat pump impossible, but they do mean extra cost, planning or design work:
One myth worth busting: heat pumps work fine in cold weather. They're standard heating in Norway, Sweden and Finland, where -25°C is normal. UK weather poses no thermodynamic challenge to a modern heat pump. The performance drop in very cold weather is real but small, around 10-15% efficiency loss at 0°C compared to 7°C, which the unit's sizing accounts for.
Air source is the default low-carbon heating choice for most UK homes. Ground source and air-to-air fit specific situations.
Best for
Properties with large gardens or boreholes already drilled
Grant available
£7,500 via Boiler Upgrade Scheme
Total cost
£18,000 to £35,000 before grant (much higher than ASHP)
Main advantage
Higher efficiency (SCOP 4-5) and lower running costs
Best for
Flats, open-plan homes, properties without wet central heating
Grant available
£2,500 via Boiler Upgrade Scheme (added April 2026)
Total cost
£3,000 to £8,000 before grant
Main catch
Doesn’t heat hot water; you need a separate cylinder or immersion
Ground source is more efficient but rarely worth the extra cost unless you already have a borehole or a large garden willing to be dug up. The £7,500 grant is the same for both, which makes the cost gap between £18,000 (ASHP) and £25,000+ (GSHP) entirely your problem to fund.
Air-to-air is interesting for flats and properties without existing wet central heating, but the lower grant and the lack of hot water capability limit its appeal for typical UK family homes.
Manufacturer finance through Daikin, Mitsubishi or Vaillant covers the balance over 5-10 years.
Most major heat pump manufacturers partner with finance providers to offer 0% APR over 24 months or longer-term plans at 6-10% APR. The monthly cost on a £10,000 heat pump balance over 7 years is roughly £150-£170, which many households offset against avoided boiler replacement costs and lower running bills.
The other option is to delay until the Warm Homes: Local Grant reaches your area. Councils across England are rolling out additional heat pump funding under the £15 billion Warm Homes Plan, with maximum grants varying by authority but typically reaching £10,000-£15,000 when combined with BUS for low-income households.
Air Source Heat Pump Cost
Full pricing breakdown by property size, brand and complexity. What you’ll actually pay after BUS.
Read guideHeat Pump Grant 2026
Every grant that funds a heat pump: BUS, ECO4, Warm Homes Local and the non-benefits route.
Read guideAre Heat Pumps Worth It?
Honest take on running costs, performance and whether a heat pump pays back in your specific situation.
Read guideBoiler Upgrade Scheme Guide
How the £7,500 BUS grant works, who qualifies, and how to find an MCS installer.
Read guideCommon questions
Your situation
None of the above and you can fund the install
Best route
BUS plus manufacturer financeRemoval of old boiler, installation of heat pump unit, hot water cylinder, controls and any radiator upgrades. Most installs take 2-5 days on site.
Installer commissions the system, balances the radiators, sets the weather compensation curve and walks you through the controls.