Heat pump running cost for a 5+ bedroom bungalow
A 5+ bedroom bungalow uses roughly 21,000 kWh of heat a year. At the current Ofgem price cap an air source heat pump (SCOP 3.5) would cost about £1,567/yr to run, versus about £1,816/yr for mains gas. That is roughly £250 saved a year. A typical ~11kW system costs about £14,750, or £7,250 after the £7,500 grant, paying back in about 29 years.
Your standard rate. The tariff scenario is shown separately.
Efficiency. 3.5 is typical.
On a standard tariff (price cap)
electricity at 26.11p/kWh
£250 /yr saved
Heat pump £1,567/yr · payback 29 yrs
On a heat pump tariff (~15p/kWh)
cheap-rate electricity
£916 /yr saved
Heat pump £900/yr · payback 7.9 yrs
Heat pump tariffs (Octopus Cosy, EDF, Scottish Power) offered off-peak rates of about 14p to 15p/kWh in June 2026. The ~15p scenario assumes most heating runs in the cheap hours.
- Now: mains gas heating
- £1,816/yr
- Gas standing charge saved
- £106/yr
- Indicative system size
- ~11kW
- Install after grant
- £7,250
- CO₂ saved
- 3,028 kg/yr
If you buy through links on this site we may earn a commission. It never changes the price you pay.
Estimate only. Real figures depend on your home, install and tariff. Prices: Ofgem cap, Jul-Sep 2026.