Air source heat pumps have gone from a niche choice to the default recommendation for anyone replacing a heating system in the UK. The technology is proven, the grant support is generous and installer numbers have grown sharply. The sticking point for most households is the same as it has always been: what does it actually cost?
This guide sets out realistic 2026 figures for supply and installation, explains how the £7,500 grant works, and covers the extras that quotes often gloss over, from radiator upgrades to hot water cylinders.
A full air source heat pump installation costs £8,000 to £15,000 before support. The Boiler Upgrade Scheme grant takes £7,500 off that in England and Wales, leaving most households paying £2,500 to £7,500. Running costs are broadly similar to a gas boiler on a standard tariff and lower on a dedicated heat pump tariff, provided the system is designed properly.
What You Are Actually Paying For
A heat pump quote covers far more than the white box on the wall outside. Understanding the parts helps you compare quotes on a level footing.
- The heat pump unit: £2,500 to £5,500 depending on brand and output. Most UK homes need 5kW to 12kW.
- Hot water cylinder: £800 to £1,800 supplied. Heat pumps cannot use a combi arrangement, so if you have no cylinder you will need one, plus somewhere to put it.
- Labour and commissioning: £2,000 to £4,000 for a two or three day installation by a qualified team.
- Radiator upgrades: £150 to £350 per radiator fitted. Many homes need three to six changed to suit the lower flow temperature.
- Pipework, controls and electrics: £500 to £1,500 for new controls, condensate drainage and any consumer unit work.
Installation Costs by Property Size
Prices below are typical 2026 totals for supply and full installation before the grant is applied, assuming a straightforward job on a property with reasonable insulation.
| Property Type | Typical Cost Before Grant |
|---|---|
| Two bedroom flat or small terrace (5 to 6kW) | £7,500 to £10,000 |
| Three bedroom semi (7 to 9kW) | £9,000 to £13,000 |
| Four bedroom detached (10 to 12kW) | £11,000 to £15,000 |
| Large or older detached (12kW plus) | £14,000 to £20,000 |
Subtract £7,500 from each figure if you qualify for the Boiler Upgrade Scheme. That puts a typical three bedroom semi at £1,500 to £5,500 out of pocket, which is close to the cost of a new boiler installation in many cases.
The £7,500 Boiler Upgrade Scheme
The Boiler Upgrade Scheme (BUS) is the main support route in England and Wales. It pays £7,500 towards an air source heat pump when you replace a fossil fuel system. The key points for 2026:
- Who qualifies: Owners of homes and small non domestic buildings replacing gas, oil or LPG heating. New builds generally do not qualify.
- How it is paid: Your MCS certified installer applies and deducts the grant from your quote. You never claim it yourself.
- Scotland: Home Energy Scotland offers grants and interest free loans instead, currently worth up to £7,500 as a grant plus optional loan funding.
- Conditions: The installation must meet MCS standards and the property needs a valid EPC. Insulation recommendations no longer block the grant.
Running Costs Compared With a Gas Boiler
A heat pump delivers three to four units of heat for every unit of electricity it uses. That multiplier, the seasonal coefficient of performance, decides your bills. At 2026 prices of roughly 24p per kWh for electricity and 6.5p for gas, a system needs an efficiency of about 3.5 to beat gas on a standard tariff.
- Well designed system, standard tariff: £700 to £1,100 per year for a typical three bedroom semi, roughly level with gas.
- Well designed system, heat pump tariff: £550 to £900 per year. Dedicated tariffs with cheaper off peak electricity are now widely available.
- Poorly designed system: £1,200 or more per year. Oversized units, undersized radiators and badly set controls are the usual culprits.
Heat pumps pair particularly well with underfloor heating, which runs at exactly the low flow temperatures where heat pumps are most efficient, and with solar panels, which can supply a meaningful share of the electricity the pump uses.
What Affects the Final Price?
- Radiator survey results: The single biggest variable. A home that needs eight radiators changed will cost £1,500 to £2,500 more than one that needs none.
- Cylinder location: Finding space for a 200 to 250 litre cylinder in a home built around a combi boiler can add joinery and pipework costs.
- Insulation standard: A leaky house needs a bigger, dearer pump and costs more to run. Loft top ups and draught proofing before the survey often pay for themselves.
- Unit siting: Long pipe runs between the outdoor unit and the cylinder add cost. Noise rules mean the unit must sit a sensible distance from neighbouring windows.
- Region: London and the South East quotes run 15 to 25 percent above the national average, as with most trades.
Choosing an Installer
Only MCS certified installers can access the grant, so that certification is your starting filter. Get at least three quotes and insist each one includes a full room by room heat loss calculation rather than a rule of thumb estimate. A proper survey takes a couple of hours; a quote produced in fifteen minutes from the doorstep is a warning sign. Ask each installer for the design flow temperature too. Lower is better, and anything above 50 degrees C suggests the design leans on the pump working harder rather than the emitters being right.
Budget £8,000 to £15,000 before support for a full air source heat pump installation, and £2,500 to £7,500 after the Boiler Upgrade Scheme grant in England and Wales. Insist on a room by room heat loss survey, budget honestly for radiator upgrades and a cylinder, and pick a heat pump electricity tariff once the system is in. Done properly, the running costs match or beat a gas boiler and the unit should outlast one by five years or more.