Heat Pump vs Gas Boiler: Which Is Cheaper to Run in 2026?

The Running Cost Comparison

At current energy prices on standard tariffs, heat pumps and gas boilers are roughly comparable in running costs. A gas boiler costs approximately £650-£750/year for a typical 3-bed home. An air source heat pump at SCOP 3.6 costs £610-£720/year. The difference is marginal — but this changes dramatically with smart tariffs.

On Cosy Octopus (11.7p/kWh off-peak), heat pump running costs drop to £350-£450/year — saving £250-£400 annually versus gas. As the grid decarbonises and potential carbon taxes on fossil fuels arrive, the gap will widen further. Gas standing charges (£120-£180/year) can also be eliminated entirely when switching to a heat pump.

Off-Gas-Grid Properties: Clear Winner

For properties currently on oil (common in rural Norfolk, Suffolk, and fenland villages like Littleport, Lakenheath, Mildenhall, and Brandon), heat pumps are clearly cheaper. Oil boiler running costs of £1,200-£1,800/year drop to £610-£720/year with a heat pump — savings of 30-50%. Many off-gas villages around Ely and in Breckland have oil-dependent housing stock where heat pumps provide immediate financial benefit alongside the £7,500 BUS grant.