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Electric heater vs central heating cost UK: the short answer
Per unit of energy, electricity is significantly more expensive than gas. Under the Ofgem price cap for 1 July to 30 September 2026, the average direct debit unit rate across England, Scotland and Wales was 26.11p/kWh for electricity and 7.33p/kWh for gas — electricity cost roughly 3.5 times as much as gas per kWh. Northern Ireland has a separate regulator and is not covered by this cap. Ofgem was due to confirm the next cap, covering October to December 2026, by 26 August 2026, so if you're reading this later, check your own current tariff or use the calculator below.
That gap means a gas-fired central heating system is almost always cheaper per unit of heat delivered. But that's only half the picture — the other half is how much space and time you're heating.
Why the electric heater sometimes still wins
A gas boiler heats water that's pumped around the whole house, whether you're using every room or not — and it doesn't turn every unit of gas into useful heat, as some is lost through flue gases and standing losses. So the real-world gap is narrower than the raw 3.5x suggests. An electric heater heats only the room it's in, with broadly all its electrical input converted to heat at the appliance.
So the real comparison isn't "electricity vs gas price" — it's the cost of heating one room with a heater against the cost of running the boiler to keep that same room warm. When you only use a fraction of the house, that difference in scope can outweigh electricity's higher unit price.
The decision framework
An electric heater suits one room for limited hours; central heating is the more efficient choice for anything bigger or longer.
A quick guide:
- Heating one room, for a short evening stretch, while the rest of the house stays unheated: an electric heater can genuinely work out cheaper, because you're not paying to heat rooms you're not in.
- Heating the whole house, or several rooms, for several hours: central heating almost always wins, because the per-kWh price gap dominates once you're covering a similar amount of space.
- Running a heater all day "instead of the boiler": this is the classic expensive mistake. A 2kW heater left on for hours adds up fast at the 26.11p/kWh cap rate for 1 July to 30 September 2026, and it rarely replaces the equivalent boiler time — it usually runs on top of, or far longer than, the heating would have been on.
- Cold snaps or whole-house comfort: central heating is built for consistent warmth; a portable heater supplements it but isn't a substitute in a poorly insulated or very cold home.
Check it with your own numbers
Every household's answer depends on the heater's wattage, your tariffs, and how many rooms and hours you'd otherwise heat. Rather than rely on a rule of thumb, use our free electric heater cost calculator to see what your heater costs per hour on your own tariff, then compare that against heating the same room via the boiler. For the fuller cost breakdown, see our guide on electric heater running cost UK, plus more tools in our heating tools hub and energy tools section.
Results are estimates only — always check against your own bill or supplier.
Frequently asked questions
Q: Is it cheaper to use an electric heater or central heating in the UK? A: It depends on scope. Electricity costs several times more than gas per kWh, so central heating is usually cheaper for warming the whole house or multiple rooms for extended periods. An electric heater can be cheaper only when you're heating a single room for a limited time and would otherwise be heating a much larger space.
Q: What's the cheapest way to heat one room in the UK? A: For a single room used for a short period, a well-sized electric heater run only while you're in that room is often the most cost-effective option, since it avoids heating the rest of the house. Check the wattage and your tariff in the calculator to see your own figure.
Q: Should I turn my heating off and use a heater instead? A: Only if you're consistently occupying one room and would otherwise be heating unused rooms too. If you use several rooms through the day or need consistent whole-house warmth, turning the central heating off in favour of a heater usually costs more, not less.
Q: Is it cheaper to heat one room than the whole house? A: Generally yes — heating less space for less time reduces energy use regardless of the source. The question is which method (electric heater or central heating with other radiators turned down) is the cheaper way to achieve that for your specific setup.
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Results are estimates only - always check against your own bill or supplier.