Costs and comparisons
The cheapest way to heat one room
The short answer
Every electric heater turns one unit of electricity into one unit of heat. Nothing on sale in the UK beats that, whatever the advertising says. What varies is how much heat you waste — and that is where the savings live.
Written and checked by the RapidHeat UK team · Last updated September 2026 · how we work out running costs
Key takeaways
- Cheapest of all: draught-proofing, curtains and a heated throw before you buy any heater.
- For a single room, a thermostatic electric heater usually beats firing up central heating.
- The biggest saving is always heating fewer hours, not buying a different heater.
The honest league table
| Option | Typical power | Cost per hour at 27p/kWh | What you actually get |
|---|---|---|---|
| Heated throw or electric blanket | 60–120 W | 2p–3p | You are warm; the room is not |
| Heated clothes airer or footwarmer | 100–300 W | 3p–8p | Very local warmth |
| Small plug-in heater with thermostat | 1,000–1,500 W | 27p–41p while the element is on | A genuinely warm room |
| Same heater with no thermostat | 1,000–1,500 W | 27p–41p continuously | Warm room, higher bill |
| Gas central heating | Whole system | Depends on boiler output, efficiency and gas rate | Several rooms or the whole home |
Unit rates change with the price cap and your tariff, so use your own p/kWh figure. The arithmetic is in running costs.
The rule that decides it
Heating one room electrically can cost less than heating a whole house with gas when you are only using one room. The result depends on your boiler, tariffs, insulation, room count and heating schedule. Compare your own figures in electric heater vs central heating.
Six habits that save more than any purchase
- Close the door of the room you are heating.
- Draught-proof the door, letterbox and old window frames.
- Close curtains at dusk — glass is where the heat goes.
- Set a target of 19–20°C instead of turning a dial to maximum.
- Use a timer so nothing runs while the room is empty.
- Turn radiator valves down in rooms nobody is in.
What about "energy saving" heaters?
Any heater claiming to produce more heat than the electricity it consumes is claiming something physics does not allow. Genuine savings come from three things only: a thermostat that stops the element, a timer that limits the hours, and heating a smaller space. Be sceptical of anything else.
Warmth per pound in practice
If you just want to stop feeling cold on the sofa, a heated throw at 3p an hour is unbeatable. If you want a room you can work, eat or get dressed in, you need a properly sized heater with controls — and used well, that is still a fraction of firing up the whole house.
Where RapidHeat sits
RapidHeat is the second category: a compact ceramic heater with a thermostat and timer, sized for rooms up to about 12 m², that reaches temperature in around five minutes and then throttles back rather than running flat out. It will not beat a heated blanket on pence per hour, and we are not going to pretend it does — it makes a whole room comfortable without heating the rest of the house. See prices and bundles.
RapidHeat ceramic heater
4.8/5 · 1,247 UK customers£49.95· £89.91 for two · £110.89 for three (about £36.96 each)
- Thermostat, timer and remote
- Warm room in about 5 minutes
- Free tracked UK delivery
- 30-day money-back guarantee
Perfect for my cold office
I have a small office with a door that gets really cold because the building management keeps the winter temperature far too low for comfort. I plugged this into the socket above my desk and now I am warm without anyone even knowing it is there. I love it.
Great in the bathroom
We use it to take the chill off the bathroom before the kids' bath time. Warms up fast and the timer is handy. Four stars only because I wish the display were a little dimmer at night.
Worth being straight about: RapidHeat is built for rooms up to about 12 m². It is not a replacement for central heating and it will not transform an open-plan lounge or an uninsulated garage. If it is not right for your room, send it back within 30 days.
Questions people ask
- What is the cheapest way to heat one room?
- In order of cost: better insulation and draught-proofing, a heated throw or electric blanket (about 3p an hour), a right-sized thermostatic electric heater (14p to 40p an hour at 27p per kWh), then central heating for the whole house.
- Is it cheaper to use an electric heater or the central heating?
- Electric spot heating is most competitive for one enclosed room over a limited period. Gas central heating becomes more competitive as more rooms need heat, but the break-even point depends on tariffs, boiler efficiency, insulation and controls.
- Do halogen heaters cost less to run?
- A 400 W halogen bar is cheap per hour and warms you directly, but it does not raise the room temperature much. It is a personal warmer rather than a room heater.
- Does turning a heater up warm the room faster?
- A higher wattage setting does warm the room faster, but setting the thermostat to 28°C does not — the room heats at the same rate and then overshoots, costing you more.
Heat the room you are in, not the whole house
Order RapidHeat today with free tracked UK delivery and a 30-day money-back guarantee.
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