Heating accounts for around 60–70 % of a typical UK household’s energy bill. Choosing the right heating system — or understanding the costs of your existing one — can make a significant financial difference year on year. This guide compares gas, direct electric, and heat pump heating using realistic 2026 UK energy prices and a worked example for a typical three-bedroom semi-detached house.
2026 UK Energy Prices
The Ofgem price cap sets the unit rate and standing charge for default tariffs. As of early 2026, typical rates on the standard variable tariff are:
- Gas: approximately 6.0–7.0 p/kWh (unit rate)
- Electricity: approximately 24–27 p/kWh (unit rate)
- Economy 7 (off-peak electricity): approximately 15–18 p/kWh off-peak, 27–30 p/kWh on-peak
These figures change quarterly with the price cap and can vary by region and tariff. Always check the current Ofgem cap before making heating decisions.
What Is the Coefficient of Performance?
Before comparing costs, it helps to understand efficiency:
- A gas boiler converts gas to heat at around 90–95 % efficiency (A-rated condensing boilers). So every 1 kWh of gas produces roughly 0.90–0.95 kWh of usable heat.
- Direct electric heaters are 100 % efficient at point of use — 1 kWh of electricity = 1 kWh of heat. They are costly to run purely because electricity is so much more expensive per unit than gas.
- Air source heat pumps move heat rather than generate it, achieving a Coefficient of Performance (COP) of 2.5–4.0 in typical UK conditions. A COP of 3 means 1 kWh of electricity produces 3 kWh of usable heat.
The Seasonal COP (SCOP) across the heating season is the more useful figure — typically 2.5–3.2 for air source heat pumps in the UK climate.
Worked Example: 3-Bed Semi-Detached
A typical mid-terrace or semi-detached house with double glazing and loft insulation might require around 12,000–14,000 kWh of heat per year for space heating and hot water.
Using 13,000 kWh of heat demand and 2026 unit rates:
| System | Efficiency / COP | Energy input needed | Unit rate | Annual fuel cost |
|---|---|---|---|---|
| Gas condensing boiler | 92 % | 14,130 kWh gas | 6.5 p/kWh | £919 |
| Direct electric heaters | 100 % | 13,000 kWh electricity | 25 p/kWh | £3,250 |
| Economy 7 storage heaters | ~100% (off-peak biased) | ~11,000 kWh off-peak | 16 p/kWh | ~£1,760 |
| Air source heat pump (SCOP 2.8) | 280 % | 4,643 kWh electricity | 25 p/kWh | £1,161 |
| Air source heat pump (SCOP 3.2) | 320 % | 4,063 kWh electricity | 25 p/kWh | £1,016 |
Standing charges and boiler/heat pump service costs are not included above. Add:
- Gas boiler: ~£110–£130/year for annual service + £105–£120/year gas standing charge
- Heat pump: ~£120–£180/year for annual service (no gas standing charge)
Gas Boiler: The Baseline
For most UK homes currently on the gas grid, a modern condensing gas boiler remains the cheapest heating option to run on a per-year basis at 2026 prices. The all-in annual cost for a 3-bed semi is typically £1,000–£1,400, including service and standing charges.
The risk with gas is price volatility and the government’s long-term policy direction: the Future Homes Standard (applying to new builds from 2025) prohibits gas boiler installation, and there is ongoing policy pressure to phase gas out of existing homes over the 2030s, though no firm mandatory replacement date for existing boilers has been set as of 2026.
Direct Electric: Expensive but Simple
Direct electric heating (panel heaters, fan heaters, night storage heaters) is the most expensive heating method on a running-cost basis in the UK — up to 3–4 times the annual fuel cost of gas. It is nonetheless common in:
- Flats without a gas connection
- Properties where gas infrastructure upgrade is prohibitively expensive
- Supplementary heating in well-insulated extensions
Economy 7 storage heaters partially close the gap by using cheaper overnight electricity, but require good insulation to retain heat through the day and are less comfortable to control than modern heating systems.
Heat Pumps: Lower Running Costs Than Electric, But Not Always Cheaper Than Gas
At current energy prices, an air source heat pump running at SCOP 3.0 costs roughly £1,000–£1,200/year to heat the same 3-bed semi that a gas boiler heats for £900–£1,100/year. The gap is smaller than many assume — and at times (depending on tariff) they can be broadly comparable.
Where heat pumps genuinely save money is in homes that are currently off-grid (oil, LPG, or direct electric), where fuel costs are significantly higher:
- Oil boiler: 9–11 p/kWh effective cost (oil at ~65–75 p/litre, ~10 kWh/litre) → annual running cost £1,300–£1,600
- LPG boiler: 12–16 p/kWh effective cost → annual running cost £1,700–£2,300
In off-grid scenarios, a heat pump’s running cost can be 30–50 % lower, giving payback periods of 8–14 years against the installation cost — a far more compelling case than the gas-grid comparison.
Capital Costs and Payback
| System | Typical installed cost |
|---|---|
| Gas condensing boiler (replacement) | £1,800–£3,500 |
| Direct electric heaters (full house) | £1,500–£4,000 |
| Economy 7 storage heaters (full house) | £2,000–£5,000 |
| Air source heat pump (fully installed) | £8,000–£15,000 |
| Ground source heat pump | £15,000–£25,000 |
The Boiler Upgrade Scheme (BUS) grant of £7,500 (as of 2026) reduces heat pump costs materially. After the grant, a mid-range ASHP installation might cost £5,000–£9,000 net.
Payback vs gas (after BUS grant, 3-bed semi):
- Running cost saving: ~£0–£200/year (marginal at current prices)
- Net capital difference vs new gas boiler: ~£3,500–£6,500 more for heat pump
- Implied payback: 18–40+ years on running costs alone
However, if the gas boiler comparison point is a replacement that would cost £2,500–£3,500 anyway, and you factor in likely electricity-to-gas price ratio convergence over 10–15 years, the case improves. Many householders also weigh in carbon reduction, future-proofing, and EPC score improvements.
Electricity Tariffs Designed for Heat Pumps
Octopus Cosy, Intelligent Octopus, and other time-of-use tariffs offer significantly cheaper off-peak rates (sometimes 7–12 p/kWh) that dramatically improve heat pump economics when the system can pre-heat the building during cheap periods. On an optimised time-of-use tariff with a COP of 3, effective heat cost can fall to 2.5–4 p/kWh — cheaper than gas.
Key Takeaways
- Direct electric is always the most expensive option at current UK tariffs — avoid it if gas or a heat pump is feasible
- Gas boilers remain cheapest to run on-grid at 2026 prices, but the margin over heat pumps is narrowing
- Heat pumps make strongest financial sense for off-grid properties or with time-of-use tariffs
- The BUS grant of £7,500 materially changes the capital equation for heat pumps
- Building Regulations Part L requires all new or replacement boilers to be condensing type and to be properly controlled with TRVs and thermostats
