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.
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 | Around 10p–25p once up to temperature | 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 house | Whole system | Often £1+ per hour of boiler firing | Everywhere warm, including empty rooms |
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 is cheaper than heating the whole house with gas whenever you are only using one room. As soon as the family spreads across three rooms, central heating wins. Full working 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.
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.
