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Heat pump vs gas boiler

Compare annual running costs of a heat pump vs a gas boiler at your actual energy rates. Adjust everything — the answer updates as you type.

Prices checked 1 July 2026
6,000 typical UK: 12,000 26,000

12,000 kWh / yr

p/kWh
p/kWh
2.5 typical: 3.5 4.5

3.5

75% typical: 90% 95%

90%

Annual running costs

Based on your inputs

Heat pump

£0/yr

0 kWh electricity used

Gas boiler

£0/yr

0 kWh gas used

Annual saving with heat pump £0/yr

CO2 emissions

Gas boiler 0 kg/yr
Heat pump 0 kg/yr
Difference 0 kg/yr
With the £7,500 BUS grant, your heat pump install could cost £1,500–£6,500 after the grant.
A well-designed heat pump with SCOP above 3.5 typically costs less to run than a gas boiler at current UK prices. Below 3.0, gas still wins on running cost alone.

How the comparison works

Heat pump running cost — your heat demand divided by the heat pump's SCOP (Seasonal Coefficient of Performance) gives the electricity used in kWh. A SCOP of 3.5 means for every 1 kWh of electricity the heat pump produces 3.5 kWh of heat. The cost is that electricity used times your electricity rate.

Gas boiler running cost — your heat demand divided by the boiler's efficiency gives the gas used. A 90% efficient boiler uses 10% more gas than the heat it delivers. The cost is that gas used times your gas rate.

SCOP matters most. A well-designed heat pump install (correctly sized, good controls, well-insulated home) can achieve SCOP 3.5–4.5. A cheap or poorly designed install might only hit 2.5–3.0, making running costs similar to or higher than gas.

BUS grant. The Boiler Upgrade Scheme gives £7,500 off an air source heat pump in England and Wales. Your installer claims it and passes the saving to you. Typical install costs are £9,000–£14,000 before the grant, so you'd pay roughly £1,500–£6,500.

Keep going

Common heat pump questions

At the price cap, a heat pump with SCOP 3.5 costs about £80-100 more per year than a gas boiler. However, on a heat pump tariff like Octopus Cosy, the heat pump becomes £200-300 cheaper per year. The BUS grant (£7,500) covers the upfront difference. Read our full running cost comparison.

A well-designed system in a reasonably insulated home should achieve SCOP 3.5-4.0. The best installs reach 4.5. Below 3.0, the installer has likely undersized or poorly designed something. The SCOP slider lets you model different outcomes — try 3.5 for a good install, 2.8 for a mediocre one.

Better insulation always helps, but it's not always essential. A heat pump can work in most UK homes. Good loft insulation (300mm) and double glazing make the biggest difference. A proper heat loss survey will tell you if insulation upgrades are needed first — a good installer won't proceed without one.

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