Air Source Heat Pump Cost UK (2026)
Last updated 5 October 2026 · Prices based on the Ofgem price cap (October 2026 – December 2026)
Air source heat pumps extract heat from outside air, even in winter, and are the most common low-carbon heating upgrade in the UK. They sit outside like a large air-conditioning unit and connect to your radiators and a hot water cylinder.
Heat pump vs gas boiler running cost calculator
Gas boiler: £1,042 a year. Heat pump: £1,009 a year. Heat pump saves about £33 a year.
- Gas boiler / year
- £1,042
- Heat pump / year
- £1,009
- Difference
- −£33
Boiler: 11500 kWh ÷ 88% × 7.97p. Heat pump: 11500 kWh ÷ SCOP 3 × 26.32p.
Air source heat pump cost by unit size
| Unit size | Suits | Installed cost | After grant |
|---|---|---|---|
| 5kW | Flat or small terrace | £8,000–£9,500 | £500–£2,000 |
| 8kW | 3-bed semi | £9,500–£12,000 | £2,000–£4,500 |
| 12kW | 4-bed detached | £12,000–£14,000 | £4,500–£6,500 |
| 16kW | Large older home | £14,000–£16,000 | £6,500–£8,500 |
Running cost by property (vs gas boiler)
| Property type | Typical cost | Annual saving | Payback |
|---|---|---|---|
| Flat (6,000 kWh heat) | £526 | £543 gas | — |
| Semi (11,500 kWh) | £1,009 | £1,042 gas | — |
| Detached (16,000 kWh) | £1,404 | £1,449 gas | — |
What affects the cost
Unit capacity
Sized from a heat loss survey, usually 5–16kW.
Outdoor space
Needs a wall or ground position with airflow, ideally at least 1m from the boundary.
Planning
Most installations are permitted development in England.
Noise and siting
Moving the unit further from the house adds pipework.
Flow temperature
Lower flow temperatures raise efficiency but may need bigger radiators.
How to reduce the cost
- Ask for a guaranteed SCOP in the quote
- Keep the unit clear of leaves and snow
- Leave it running steadily — don't switch on and off
- Use weather compensation settings
- Pair with solar panels to offset running costs
Frequently asked questions
What size air source heat pump do I need?
Most 3-bed homes need 6–9kW. Only a heat loss survey can confirm.
Are air source heat pumps noisy?
Modern units are around 40–60dB at 1m — about the level of a fridge to a quiet conversation.
Do I need planning permission?
Usually not in England under permitted development, subject to size and siting rules.
Can I keep my gas boiler as backup?
Hybrids exist but don't qualify for the Boiler Upgrade Scheme grant.
How efficient are air source heat pumps?
A good installation achieves SCOP 3–4: three to four units of heat per unit of electricity.
Sources and methodology
Energy prices come from the Ofgem price cap for Direct Debit customers (GB average). Installation costs are typical UK ranges from installer quotes and industry guidance, rounded. Savings use today's rates and do not predict future prices.