Heat pump vs boiler running costs in 2026
The question that decides most installations, answered with arithmetic instead of advocacy: what each heating system costs to run this year, for the same warm house.
The method (so you can check it)
Take a typical UK three-bed semi needing 14,000 kWh of heat a year for space heating and hot water. Divide by each system's realistic seasonal efficiency to get fuel input, multiply by 2026 fuel prices: gas at ~6.5p/kWh, electricity at ~26p/kWh standard or ~17p on a heat pump tariff, heating oil at ~7p/kWh-equivalent, LPG at ~10p. Standing charges excluded (you pay the electricity one regardless; ditching gas entirely saves its ~£110/year standing charge — we credit that where it applies). Round numbers, deliberately conservative.
The league table — annual cost for the same heat
- Ground source heat pump, SCOP 4.2, heat pump tariff — 3,333 kWh electricity ≈ £570
- Air source heat pump, SCOP 3.5, heat pump tariff — 4,000 kWh ≈ £680
- Air source heat pump, SCOP 3.5, standard tariff — 4,000 kWh ≈ £1,040
- Modern gas boiler, 90% efficient — 15,550 kWh gas ≈ £1,010 plus gas standing charge ≈ £1,120
- Oil boiler, 88% efficient — ≈ £1,110
- LPG boiler, 88% efficient — ≈ £1,590
- Poorly installed ASHP, SCOP 2.5, standard tariff — 5,600 kWh ≈ £1,460 (the cautionary row)
- Direct electric heating — 14,000 kWh ≈ £3,640
Read the table twice and the real findings emerge. A good heat pump on the right tariff is the cheapest way to heat a UK home in 2026 short of burning wood you already own. A good heat pump on a standard tariff sits within noise of a gas boiler once the gas standing charge is counted. And a bad heat pump install is more expensive than the boiler it replaced — the entire running-cost case lives or dies on the SCOP, which is set by design quality, not by the badge on the unit. That is why the grant requires MCS-certified installers, and why our cost pages bang on about heat loss calculations and radiator sizing.
Where the comparison is a landslide
Off the gas grid, there is no contest to referee. Against LPG the heat pump saves £700–£900 a year on our reference house; against direct electric heating it saves around £2,500; against oil it saves modestly on fuel and decisively once boiler servicing, tank maintenance, and price volatility join the ledger. This is why off-grid homes — about 15% of the UK — have been the fastest adopters under the Boiler Upgrade Scheme, and why the £7,500 against an after-grant cost of £4,000–£8,500 frequently produces sub-five-year paybacks for oil and LPG households.
How to land on the right side of the table
Three controllables. Demand a room-by-room heat loss calculation and a design flow temperature of 45°C or lower — it is the single best predictor of real-world SCOP. Switch tariffs the week the system is commissioned; running a heat pump on a default standard tariff leaves £300+ a year on the table. Run it like a heat pump — steady and low, with weather compensation doing the thinking, not morning blasts. Get those three right and the brochure numbers are not optimistic; they are conservative. Our myths page deals with the remaining folklore, including the January question.