Every plug-in electric heater turns one unit of electricity into the same amount of heat, so a 1kW heater costs about 26p an hour whatever type it is. The cheapest heater to run is the one with the lowest wattage that still warms your room, controlled by a thermostat and timer so it only draws power when you need it.
That figure uses Ofgem's price cap for 1 October to 31 December 2026: 26.32p per kWh for electricity (Direct Debit, average for England, Scotland and Wales, announced 26/08/2026). VAT has been removed from electricity bills from 1 October 2026 to 31 March 2027, so that is the price you pay.
The sum: watts ÷ 1,000 × price per kWh
| Heater setting | Sum | Cost per hour |
|---|---|---|
| 600W (oil radiator, low) | 0.6 × 26.32p | about 16p |
| 800W (fan heater, low) | 0.8 × 26.32p | about 21p |
| 1.2kW (small convector) | 1.2 × 26.32p | about 32p |
| 1.5kW | 1.5 × 26.32p | about 39p |
| 2kW | 2 × 26.32p | about 53p |
| 2.5kW (large oil radiator, high) | 2.5 × 26.32p | about 66p |
Adverts that call one heater "cheaper to run" than another at the same wattage are talking about how the heat is used, not how much of it is made. That's where the real savings are.
Oil-filled radiator vs convector vs fan heater vs halogen
- Oil-filled radiator: slow to warm up, but the oil holds heat and keeps radiating after the thermostat clicks off. Silent. Best for rooms you sit in for hours, like a bedroom overnight or a home office all day. Three power settings let you run it at 600W or 800W when the room only needs topping up.
- Convector or panel heater: warms the air, which circulates round the room. Quicker than an oil radiator, fanless and quiet, and usually slim enough to wall mount. The ones below have weekly timers, which is the single best money-saver for a room you use at set times.
- Fan heater or ceramic heater: hot air in seconds, but the room cools quickly when it stops. Cheapest to buy, and cheapest to run for short bursts: warming a bathroom or a cold study for 20 minutes.
- Halogen heater: heats you, not the room, like standing in sunshine. Fine for sitting right in front of it, poor for a whole room. We don't currently stock halogen heaters.
Electric heaters compared
| Heater | Type | Power settings | Room size | Controls | Price |
|---|---|---|---|---|---|
| 1500W PTC Ceramic Fan Heater | Fan | 800W / 1,500W | up to 15m² | Thermostat, 24-hour timer | £25.95 |
| 1500W Oil Filled Radiator | Oil-filled | 600W / 900W / 1,500W | 9–15m² | Thermostat | £47.95 |
| 1.2kW Electric Convector Heater | Convector | 1,200W | 8–12m² | Thermostat, weekly timer, remote | £59.95 |
| 2000W Oil Filled Radiator, 9 Fin | Oil-filled | 800W / 1,200W / 2,000W | 9–15m² | Thermostat | £59.95 |
| Tower Fan Heater with Oscillation | Fan | 1,100W / 2,200W | 20–25m² | Thermostat, 8-hour timer, remote | £64.95 |
| 2000W Electric Convector Heater | Convector | 2,000W | 15–20m² | Thermostat, weekly timer, remote | £73.95 |
| 1500W Smart Electric Panel Heater | Panel | 1,500W | 15–18m² | App, 24-hour and weekly timer | £74.95 |
How to choose the cheapest heater for you
- Work out how long you'll run it. Minutes at a time: a fan heater. Hours at a time: an oil-filled radiator or a convector with a thermostat.
- Don't oversize it. A 2kW heater in a small bedroom reaches temperature fast, then cycles on and off. A lower setting on a thermostat does the same job with less overshoot. Match the room size in the table to your floor area (length × width).
- Insist on a thermostat. Without one, a heater runs flat out until you switch it off. Every heater above has one.
- Use the timer. Warming the room for the 30 minutes before you get up costs a fraction of running it all night.
- Heat the room, not the house. Electricity costs 26.32p per kWh against 7.97p for gas at the same price cap. An electric heater saves money when it lets you turn the central heating down and warm only the room you're in. It costs more if it runs alongside the central heating.
- Close the door and stop draughts. Nothing makes a heater cheaper to run than keeping the heat in.
Compare all oil-filled radiators, convectors and fan heaters in our Heating range.
Frequently asked questions
Are oil-filled radiators cheaper to run than convector heaters? Not per hour at the same wattage: 1kW costs about 26p either way. An oil radiator can work out cheaper over an evening because its stored heat keeps the room warm while the thermostat has it switched off.
How much does a 2kW heater cost to run per hour? About 53p an hour on full power at the October–December 2026 price cap (2 × 26.32p). Less in practice, because the thermostat switches it off once the room is warm.
What is the cheapest heater to run for a bedroom? A low-wattage oil-filled radiator on its thermostat. It's silent (our radiators are rated 0dB), and on its 600W setting costs about 16p an hour.
Is a fan heater expensive to run? Per hour, no more than any other heater of the same wattage. It becomes expensive when used to heat a room for hours, because the warmth disappears the moment it switches off.
Is it cheaper to use an electric heater or the central heating? For one room, an electric heater can be cheaper if you turn the central heating down. For the whole house, gas central heating is cheaper because gas costs less than a third of the price per kWh.
