Air Source Heat Pump Cost UK — 2026 Prices, Grants, Payback
The UK Boiler Upgrade Scheme (BUS) gives you £7,500 off an air source heat pump (ASHP). Post-grant, install cost is £5,500–£9,000. Here is the full 2026 breakdown vs staying on gas.
Step-by-step method
Install cost
£13,000–£16,500 typical for a 3-bed UK home, minus £7,500 BUS grant = £5,500–£9,000 net. Includes cylinder, controls, radiator upgrades.
Running cost
With a COP of 3.5, 1kWh electricity = 3.5kWh heat. At 27p/kWh electricity vs 6p/kWh gas, ASHP is ~£20/year cheaper than a modern gas boiler for average usage.
Radiator upgrades
Because ASHPs run at 45–55°C not 70°C, 20–40% of radiators need upsizing (K2 doubles) to deliver the same heat. Budget £600–£1,200.
15-year TCO
ASHP £5,500 install + £15,000 running = £20,500. Modern combi £2,800 install + £15,300 running + 1x £2,500 replacement = £20,600. Roughly break-even, with lower CO2.
Frequently asked questions
How do I get the £7,500 heat pump grant?+
Your MCS-certified installer applies for the BUS grant on your behalf — you pay the net figure.
Is my house suitable for a heat pump?+
Most UK homes are. You need cavity or solid-wall insulation to a decent level, 0.4m² outside for the unit, and a hot water cylinder.