Cheapest electric heater to run in the UK
De'Longhi Dragon 4 Oil-Filled Radiator 2kW
Photographed listing — tagged buy buttons go to the retailer, not another article.
The cheapest electric heater to run is the lowest-powered one that heats the space you are in. All electric heaters are equally efficient, so the bill comes down to wattage and how long the element is on. To warm yourself, an electric blanket costs about 2.9p an hour. To warm a room, a thermostat-controlled oil radiator sized to the room: a 1.5kW model costs about £1.10 for a 5-hour evening.
Electric heater running costs compared
| Heater | Hour† | Evening* |
|---|---|---|
Electric blanket (double) Heats you, not the room | 2.9p | 7.3p |
Heated throw Heats you, not the room | 2.9p | 10p |
Heated clothes airer Dries laundry; warms a little | 7.3p | 37p |
Oil filled radiator, 1.5kW Small room, with thermostat | 37p | £1.10 |
Oil filled radiator, 2.5kW Larger room, with thermostat | 61p | £1.84 |
Convector heater, 2kW With thermostat | 49p | £1.47 |
Halogen heater, 1.2kW No thermostat; heats what it faces | 29p | £1.47 |
Fan heater, 2kW Without a thermostat | 49p | £2.45 |
†At full power. *5 hours, with thermostat models on 50–70% of the time once warm and the rest running throughout. Typical wattages; 24.5p/kWh (Oct 2026 price cap).
Lowest-power heaters in stock now
A lower-wattage heater costs less per hour but only suits a smaller room. Allow roughly 100W per square metre of a typical UK room.
| Unit | Power | Hour† | Day* | Price |
|---|---|---|---|---|
| STATUS 5 Fin Oil Filled Radiator 500W White Portable Heater, Overheat Protection | 12p/hr | 37p | £16.15 | |
| Essentials 500W Portable Oil Filled Radiator Heater White 220-240V Indicator | 12p/hr | 37p | £16.15 | |
| 500W Mini Oil Filled Radiator Portable Electric Heater Thermostat White Boxed | 12p/hr | 37p | £17.99 | |
| Status 500W 5 Fin Oil Filled Radiator Heater White Thermostat Overheat Handle | 12p/hr | 37p | £18.28 | |
| De'Longhi TRNS0505M Oil Filled Radiator - White 500W | 12p/hr | 37p | £52.70 | |
| Mini Oil Filled Radiator 650W 5 Fin Portable Electric Heater Adjustable Thermost | 16p/hr | 48p | £9.99 |
†At full power. *5 hours at 60% of full power. In stock at the last check, lowest power first. Power is read from the retailer listing.
Five ways to cut what any heater costs
Look at the kit — then buy it
Dimplex 2kW Oil-Filled Radiator
Pro Breeze OmniWarm Smart 2500W 11 Fin Oil Filled Radiator
If you buy through these links we may earn a commission at no extra cost to you. As an eBay Partner Network Affiliate and Amazon Associate, we earn from qualifying purchases. Full disclosure.
- Use the thermostat, not the top setting: it is what lets the element switch off.
- Shut the door and heat the smallest space you can.
- Heat yourself first: a blanket or throw for sitting still costs a fraction of heating the room.
- Use a timer to warm the room before you need it, then let the thermostat hold it.
- Pick the wattage for the room: an oversized heater does not save money, an undersized one never switches off.
FAQ
Cheapest heater to run: common questions
- What is the cheapest electric heater to run?
- To heat yourself, an electric blanket or heated throw: about 2.9p an hour at full power. To heat a room, the lowest-wattage oil filled radiator that warms it, run on its thermostat: a 1.5kW radiator costs 37p an hour flat out and about £1.10 over a 5-hour evening.
- Are some electric heaters more efficient than others?
- No. Every plug-in electric heater turns 1kW of electricity into 1kW of heat, whatever the marketing says about 'energy saving' models. What changes the bill is the wattage, how long the element is actually on (a thermostat switches it off once the room is warm), and whether you heat the whole room or just yourself.
- Is an oil filled radiator cheaper to run than a fan heater?
- Over an evening, usually. Both cost 49p an hour at 2kW, but the radiator's thermostat and the oil's stored heat let it switch off for longer once the room is warm, while a fan heater without a thermostat runs flat out. A fan heater is cheaper for a quick 15-minute warm-up.
- Are halogen heaters cheap to run?
- They cost 29p an hour at 1.2kW. They heat whatever they face rather than the room, so they suit a draughty spot or a garage for short spells, not a room you sit in all evening.
- Is an electric blanket cheaper than putting a heater on?
- Much cheaper: a double electric blanket costs about 7.3p for a 5-hour evening against roughly £1.47 for a 2kW heater. It only warms you, so it works best alongside a room kept cooler.