How much does an air source heat pump cost in the UK?

Typical installation costs £10,500–£14,500 for a 3-bed semi in 2025, before the £7,500 BUS grant. After the grant, most homeowners pay £3,000–£7,000 out of pocket. Smaller properties (flats, 2-bed) cost less; larger properties more.

Are air source heat pumps efficient in cold UK winters?

Yes. A typical UK ASHP delivers SCOP 2.8–3.4 across a full year, including cold periods. Efficiency drops in deep cold (below -5°C the COP may fall to 2.0–2.2), but the units keep working down to around -15°C. Sizing is more important than ambient temperature.

How long does an air source heat pump last?

Modern units typically last 15–20 years. The compressor is the wear part — usually budget for refrigerant top-up around year 8–10. Lifespan correlates strongly with installation quality and annual servicing.

Does an air source heat pump need planning permission?

In most UK locations, no — air source heat pumps are usually covered by permitted development rights. Exceptions: conservation areas, listed buildings, and where the unit is closer than 1m to a property boundary. Always check with the installer and your local council.

How noisy is an air source heat pump?

Modern UK units run at 40–48 dB at 1m — similar to a kitchen fridge. Sited well (away from bedroom windows, on a vibration-damping base, away from boundary walls that can echo), they're rarely a nuisance. Sited badly, they can be annoying. Insist on a noise assessment as part of the install design.

Air Source Heat Pumps UK: Costs, Grants & Everything You Need to Know

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Clean professional installation of a Vaillant-style white air source heat pump on the side wall of a 1930s UK semi-detached home, paved garden, late afternoon

An air source heat pump install on a typical UK 3-bed semi — the most common heat pump type in British homes.

Air source heat pumps (ASHP) are the most common type of heat pump installed in UK homes — by a wide margin. They cost less than ground source systems, need no land disturbance, and qualify for the full £7,500 Boiler Upgrade Scheme grant. For most owner-occupied UK properties, an ASHP is the practical answer to "which heat pump should I get?".

What an air source heat pump is

An air source heat pump pulls warmth out of outdoor air and uses it to heat your home. It looks like a large outdoor air-conditioning unit — typically 1m wide × 1m tall × 0.4m deep — sited next to your house. Inside, it connects to a hot water cylinder and either radiators or underfloor heating.

The unit runs a refrigerant cycle (see our how heat pumps work guide) that concentrates heat from outside and pushes it into your home's water loop. Even at -10°C outside, there's enough thermal energy in the air for the refrigerant to extract.

Installation cost in 2025

Property type	Before BUS	After BUS grant
1-bed flat	£7,000–£9,500	£0–£2,000
2-bed terrace	£8,500–£11,500	£1,000–£4,000
3-bed semi (typical)	£10,500–£14,500	£3,000–£7,000
4-bed detached	£12,500–£17,000	£5,000–£9,500
5+ bed / large	£14,500–£22,000	£7,000–£14,500

Costs include unit, installation labour, hot water cylinder upgrade, basic pipework, and commissioning. Radiator upgrades and microbore pipe rework add £500–£2,000 in many UK homes — covered in our radiator compatibility guide.

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Modern heat pump indoor controller and hot water cylinder installed in a UK utility room, neat pipework, professional finish

The indoor unit houses the controller and connects to the hot water cylinder — usually in a utility room or airing cupboard.

Running costs

A typical 3-bed semi consuming 12,000 kWh of useful heat per year:

ASHP on Octopus Cosy tariff: £900–£1,100/yr
ASHP on standard variable tariff: £1,000–£1,250/yr
New gas boiler: £1,020–£1,250/yr
Oil boiler: £1,250–£1,500/yr
LPG boiler: £1,860–£2,100/yr

Heat pump tariff choice matters more than most people expect. The same ASHP can be £150–£300 cheaper or more expensive depending on whether you're on Octopus Cosy or standard variable. Worth modelling carefully in the cost calculator.

Is your home suitable for ASHP?

Most UK homes are. The key checks:

Outdoor space for the unit (~1m² of clear floor, with 30cm clearance for airflow). Walls, sheds, paving — all fine. Awkward routes around chimneys or directly under bedroom windows are less so.
Hot water cylinder space indoors. Combi-boiler homes need to find a 600×600mm footprint somewhere — usually in an airing cupboard or utility room.
Reasonable insulation. EPC D or above is the BUS threshold; lower-rated homes may need insulation work first (often ECO4-funded).
Radiator capacity. Most homes can keep most existing radiators, with 2–4 upgrades typical in a 3-bed semi.

When ASHP isn't the right choice

Air source is rarely wrong, but a few scenarios point elsewhere:

Very rural / off-grid with large plot — ground source can pay back its premium for higher annual heat demands.
Flats with no outdoor space — ASHP needs the outdoor unit somewhere; a flat without a balcony or garden may have no viable site.
Listed building in conservation area — outdoor unit visibility can be a planning blocker. Specialist installers can sometimes find solutions; many can't.

What brands install in the UK

The major UK ASHP brands (alphabetical, no endorsement):

Daikin — strong UK distribution, wide installer network
LG Therma V — competitive on price, good performance
Mitsubishi Ecodan — well-regarded for cold-climate performance
Samsung EHS — popular, competitive pricing
Vaillant aroTHERM — established UK boiler brand pivoting hard to heat pumps
Worcester Bosch Greensource — same boiler-led brand transition
NIBE — Swedish, premium, well-engineered for cold
Grant Aerona — Irish/UK, strong rural and off-grid presence

Brand matters less than installer quality. A well-installed mid-tier unit will outperform a badly-installed premium unit. Ask your installer which brands they install regularly and why.

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Composite of typical UK home types suited to air source heat pumps: 1930s semi, Victorian terrace, modern new-build detached, all with discreet outdoor units

Most UK property types suit air source heat pumps — semi-detached, terraces, and detached homes alike.

What to ask your installer

What's the modelled SCOP for this property?
What's the design flow temperature on the coldest day of the year?
Can I see the room-by-room heat loss calculation?
Which radiators are you replacing and which are you keeping?
What size cylinder, and where will it go?
What brand and model, and what's the warranty?
Where will the outdoor unit sit and what's the noise impact?
Have you confirmed your MCS certification covers this install type?
Will you handle the BUS application paperwork?

A competent MCS-certified installer answers all of these without hesitation. If they deflect, walk away.

The bottom line

Air source heat pumps work for the majority of UK homes. With the £7,500 BUS grant, the upfront cost is comparable to a high-end boiler replacement, and running costs on a heat-pump tariff are modestly cheaper. The make-or-break factor is installer quality, not the technology itself.

Check eligibility, run the cost calculator, then choose three MCS-certified installers and compare quotes. The whole decision can take a fortnight to research and 8–14 weeks to install.