How much does it cost to run a electric combi boiler? (2026 price cap)
At the GB-average Ofgem price cap for 1 October to 31 December 2026, a electric combi boiler rated at 9kW costs £2.37 an hour to run and around £1,297 a year assuming 1.5 hours a day of heating demand.
Per hour
£2.37
Per typical use
£3.55
Per day
£3.55
Per week
£24.94
Per year
£1,297
Typical rating and how we worked this out
This page uses a typical rating of 9kW for a electric combi boiler; published figures for this appliance range from 6kW to 14kW. Electric combi boilers heat water directly with a resistive element rated 6–14kW, with 9kW a common size for a small home; because they have no flue losses they are close to 100% efficient, but on a standard electricity tariff the energy itself costs far more per kWh than mains gas. The running cost follows the same formula used across this site: watts ÷ 1,000 × hours × unit rate. Typical use is modelled as 1.5 hours a day of heating demand, which is how the per-day, per-week and per-year figures above were calculated — see the cost-to-run calculator to change the wattage, hours or region yourself.
Rate used: Ofgem price cap, 1 October to 31 December 2026, GB average electricity — 26.32p/kWh (excl. VAT, removed 1 Oct 2026–31 Mar 2027).
Cost by region
Same appliance, same use — ranked most to least expensive by region under the price cap:
| Region | Elec p/kWh | Cost per hour | Typical annual cost |
|---|---|---|---|
| Merseyside and Northern Wales | 27.86 | £2.51 | £1,373 |
| South Eastern England | 26.88 | £2.42 | £1,325 |
| Eastern England | 26.61 | £2.39 | £1,311 |
| London | 26.60 | £2.39 | £1,311 |
| South Western England | 26.58 | £2.39 | £1,310 |
| Southern Wales | 26.55 | £2.39 | £1,308 |
| North Western England | 26.49 | £2.38 | £1,305 |
| Southern England | 26.47 | £2.38 | £1,304 |
| Northern Scotland | 26.35 | £2.37 | £1,298 |
| Southern Scotland | 26.11 | £2.35 | £1,287 |
| West Midlands | 25.60 | £2.30 | £1,261 |
| Yorkshire | 25.60 | £2.30 | £1,261 |
| North Eastern England | 25.46 | £2.29 | £1,255 |
| East Midlands | 25.36 | £2.28 | £1,250 |
| Great Britain average | 26.32 | £2.37 | £1,297 |
East Midlands is cheapest at £1,250 a year; Merseyside and Northern Wales is most expensive at £1,373 a year — a gap of £123 for identical use.
How a electric combi boiler compares with similar appliances
Ranked by typical annual cost in heating & cooling, GB average:
- electric combi boiler — £1,297 a year (this page)
- air source heat pump — £1,307 a year
- night storage heater — £1,345 a year
- hot tub — £769 a year
- portable air conditioner — £692 a year
- oil-filled radiator — £576 a year
Three practical ways to cut the cost
- Set the thermostat and timer accurately rather than heating to a higher temperature than needed
- Consider an off-peak or heat-pump-friendly tariff if switching from gas, since standard electricity is priced well above gas
- Keep radiators bled and the system balanced — trapped air makes the boiler run longer to heat the same rooms
FAQs
- How much does it cost to run a electric combi boiler for an hour?
- £2.37 at the GB-average rate (26.32p/kWh, 9kW). One typical use — 1.5 hours a day of heating demand — costs closer to £3.55.
- How much does a electric combi boiler cost to run per year?
- Around £1,297 a year at the GB-average rate, assuming 1.5 hours a day of heating demand — about £24.94 a week.
- Which UK region is cheapest to run a electric combi boiler in?
- East Midlands, at £1,250 a year, against £1,373 in Merseyside and Northern Wales — £123 apart for identical use, purely from the regional rate.
- Does the exact wattage of my electric combi boiler change the cost much?
- Yes — ratings range 6kW–14kW, so the top of that range costs about 2.3x the bottom. This page uses 9kW; check your own rating plate.
- Does the October 2026 price cap affect this figure?
- Yes — figures use the Ofgem cap for 1 October to 31 December 2026. Electricity excludes VAT (removed 1 Oct 2026–31 Mar 2027); gas includes 5%. See the price cap page for the full breakdown.
Sources
- Heatable — how much energy do household appliances use — wattage and usage figures for this appliance.
- Ofgem — Energy price cap unit rates and standing charges (regional tables, read 12 September 2026).
Related
- Cost-to-run calculator and full A–Z — check any appliance or enter a custom wattage.
- Energy price cap, 1 October to 31 December 2026 — every region, every payment method.
- Back-billing calculator — if a bill for this or any appliance looks like it covers too many months.
- Free bill audit — if your overall energy costs look high regardless of any one appliance.
Send us one bill. We'll send back every overcharge — and the cheapest legitimate replacement.
Whether you run a Mayfair restaurant group or rent a flat in Salford, the audit is the same and the fee is the same: nothing, unless we save you money.