Gas Boiler vs Heat Pump

Gas BoilerAir Source Heat Pump
Install cost\£1,500\–4,000\£8,000\–15,000
After BUS grant (\£7,500)\u2014\£500\–7,500
Annual running cost\£900\–1,200\£700\–1,000
Lifespan12\–15 years20\–25 years
Needs new radiators?NoOften yes (larger ones)