How much does a heat pump cost to run per year in the UK?

Most UK 3-bed semi homes with a heat pump and a heat-pump-specific tariff (Octopus Cosy, BGE HomeEnergy) spend £500–£900/year on heating + hot water. The same home on a flat-rate electricity tariff (single 28p/kWh rate) spends £950–£1,250. Larger detached homes (4-bed, 4,000+ kWh of extra heat demand) spend roughly 50% more. Smaller flats and well-insulated new builds spend roughly 40% less. The headline number is meaningless without specifying property size, insulation level, and tariff — those three swing the answer by a factor of 2-3×.

Why does the same heat pump cost so differently to run depending on tariff?

Heat pumps consume electricity, and the per-kWh price of electricity varies more than 2× across UK tariffs. The standard variable tariff caps at ~28p/kWh in 2026. Heat-pump-specific tariffs with off-peak windows can blend down to 14-18p/kWh if you shift consumption into the cheap hours. Dynamic tariffs (Octopus Agile) can blend below 14p/kWh for households with smart-tariff controllers. Because a heat pump uses 3,000-5,000 kWh/year for a typical 3-bed home, every penny per kWh equals £30-£50/year. So the gap between a 28p flat rate and a 17p blended smart rate is £330-£550/year for the same heat pump in the same house — bigger than the cost gap to gas in most cases.

Is a heat pump always cheaper than gas to run?

No. With a poorly tuned heat pump on a flat-rate tariff in an uninsulated solid-wall home, running costs can be 20-40% higher than the same home on gas. The places heat pumps cleanly beat gas are: well-insulated homes, paired with a heat-pump-specific smart tariff, with weather compensation enabled and tuned, and a properly-sized cylinder. Done right, the running cost is 15-30% below the equivalent gas bill. Done badly, it's worse. The variance is the main reason for the 'heat pumps are expensive to run' anecdotes — they're true in the bad case.

How do oil and LPG running costs compare?

Oil and LPG are both significantly more expensive to run than mains gas in 2026. Heating oil costs roughly 9p/kWh delivered at a typical 88%-efficient boiler, working out at ~£1,200/year for the same 12,000 kWh heat demand. LPG is even worse at ~14p/kWh delivered, ~£1,900/year. Heat pumps comfortably beat both fuels even on flat-rate electricity — typical saving £200-£600/year vs oil, £700-£1,200/year vs LPG. This is why heat pump uptake in off-gas-grid properties has accelerated faster than on-grid: the running-cost case is unambiguous.

What's the biggest single thing I can do to reduce my heat pump running cost?

Switch to a heat-pump-specific tariff and schedule consumption into the cheap-rate hours. This is typically 15-30% off your annual bill for zero capex. After that, enable + tune weather compensation (10-20% more saving). After that, address any uncleared insulation (loft + cavity, ~10-20% reduction in heat demand). The three together can take a heat pump from 'parity with gas' to '25-40% cheaper than gas'. See the smart-tariff setup guide for the implementation details.

Heat pump vs gas boiler running costs UK 2026: real numbers

What we’re calculating — and why it varies

Running cost has three components: the heat demand of the home (kWh of heat needed per year), the efficiency of the heating system (how much fuel turns into useful heat), and the price of that fuel per kWh.

For gas:

Heat demand × 1 / boiler efficiency × gas price per kWh = annual cost.

For a heat pump:

Heat demand × 1 / SCOP × blended electricity price per kWh = annual cost.

The catch: every variable in those equations differs by household. The 3-bed semi number is the central anchor; your bill scales up or down with house size and insulation level.

Baseline — a typical UK 3-bed semi

Assumptions:

12,000 kWh/year of useful heat (heating + hot water).
Modern condensing gas boiler at 90% seasonal efficiency.
Air-source heat pump at SCOP 3.2 (typical UK installed performance).
Gas price: 7p/kWh (Ofgem cap, May 2026).
Standard variable electricity: 28p/kWh.
Octopus Cosy blended: ~17p/kWh (mix of peak + cheap).
Octopus Agile (automated): ~14p/kWh blended.

Annual cost calculation:

Gas boiler baseline

12,000 ÷ 0.90 × £0.07 = £933/year gas consumption. Plus standing charges (~£155/year for gas and partial standing charge attribution for the heating side) = ~£780–£900/year for the heating + hot water side of the bill.

Heat pump on standard variable

12,000 ÷ 3.2 × £0.28 = £1,050/year electricity for heating. Plus electricity standing charge (already partially attributed elsewhere) = ~£1,000–£1,100/year. Slightly worse than gas, before any optimisation.

Heat pump on Octopus Cosy

12,000 ÷ 3.2 × £0.17 = £640/year electricity for heating. About 18% cheaper than gas on the same heat demand.

Heat pump on Octopus Agile (smart-controlled)

12,000 ÷ 3.2 × £0.14 = £525/year electricity for heating. Roughly 33% cheaper than gas.

How insulation changes the picture

The heat-demand number (the 12,000 kWh in the example above) is set by your home’s insulation, not your heating system. Improvements scale linearly:

Loft top-up (no loft now → 270mm): ~20% reduction in heat demand. 9,600 kWh/year instead of 12,000. Annual saving on Cosy: ~£128.
Cavity wall (unfilled → filled): ~25% reduction. 9,000 kWh/year. Annual saving on Cosy: ~£160.
Loft + cavity + draughtproofing: ~40% combined reduction. 7,200 kWh/year. Annual saving on Cosy: ~£256.

See the fabric-first retrofit guide for the implementation order and grant routes.

How weather compensation tuning matters

SCOP is sensitive to flow temperature. Every 5°C lower flow temperature improves COP by 10-15%. A typical installer commissions at a conservative flow-temp curve; tuning down across the first winter typically improves SCOP from 3.0 to 3.5+.

Worked impact: a household with SCOP 3.0 on Cosy spends 12,000 ÷ 3.0 × £0.17 = £680/year. Tuned to SCOP 3.5: 12,000 ÷ 3.5 × £0.17 = £583/year. Saving: ~£100/year from a control setting tweak.

Scaling to other house sizes

Rule of thumb for heat demand by house type in UK 2026:

1-bed flat (well-insulated): 4,000-6,000 kWh/year
2-bed terrace: 8,000-10,000 kWh/year
3-bed semi (typical): 11,000-13,000 kWh/year
4-bed detached: 15,000-18,000 kWh/year
5-bed+ or solid-wall detached: 20,000+ kWh/year

Multiply your kWh by the SCOP-divided cost figure relevant to your tariff. The proportions stay constant — a heat pump on Cosy is roughly 80% of the gas cost regardless of house size.

Comparison to oil and LPG

Heat pumps decisively beat oil and LPG, and the gap widens with house size:

Heating oil at 9p/kWh delivered, 88% boiler efficiency: 12,000 ÷ 0.88 × £0.09 = £1,227/year. Heat pump on Cosy saves ~£600/year.
LPG at 14p/kWh delivered, 88% boiler efficiency: 12,000 ÷ 0.88 × £0.14 = £1,909/year. Heat pump on Cosy saves ~£1,270/year.
Electric resistance / panel heaters at 28p/kWh flat: 12,000 × £0.28 = £3,360/year. Heat pump on Cosy saves ~£2,720/year.

Off-gas-grid properties have the strongest running-cost case for switching, which is why DESNZ statistics show heat pump uptake accelerating fastest in rural areas.

What this means for payback

See the dedicated payback period guide for the full IRR calculation. Short version: a £7,500 BUS grant cuts net install cost to ~£6,000–£8,000. Running-cost savings of £200–£500/year vs gas put payback at 12-25 years on gas, 5-10 years on oil, 3-7 years on LPG.

The summary

The headline “is a heat pump cheaper than gas?” is the wrong question — it depends on tariff, insulation, and tuning. A heat pump on a smart tariff, with weather compensation enabled, in a home with loft and cavity insulation cleared, is reliably 15-30% cheaper than gas. The same heat pump on a flat-rate tariff in an uninsulated home is 10-20% more expensive than gas. The system design choices determine which side of break-even you land. Oil and LPG comparisons are unambiguous: heat pumps beat both in every realistic configuration.

Heat pump vs gas boiler running costs in UK 2026: the real numbers