The best heaters for large rooms and living rooms (November 2026)
Which electric heater warms a big living room or open-plan space, what size you need and what it costs to run each month at the Ofgem price cap.
The best heaters for large rooms (November 2026)
| # | Model | Type | Power | Per hour | Per month* | Controls | Score | |
|---|---|---|---|---|---|---|---|---|
| 1 | Devola DVPW2500WH Smart Glass Panel Heater 2500W Best for large rooms | Panel heater | 2,500 W | 65.8p | £59.22 5 hours a day on thermostat | Digital thermostat, weekly schedule, Wi-Fi, remote | 8.8 | Check price → |
| 2 | De'Longhi Dragon 4 TRD41025T 2.5kW Premium for large rooms | Oil filled radiator | 2,500 W | 65.8p | £59.22 5 hours a day on thermostat | Dial thermostat, timer | 8.1 | Check price → |
| 3 | Dreo Smart Whole Room Heater 714S Whole-room circulation | Fan heater | 2,000 W | 52.6p | £31.58 2 hours a day at full power | Timer, Wi-Fi | 8.0 | Check price → |
| 4 | Dimplex ECR24TiFB 2.4kW Oil-Free Radiator with Turbo Fan Fast heat, large rooms | Oil-free radiator | 2,400 W | 63.2p | £56.85 5 hours a day on thermostat | Dial thermostat, timer | 7.6 | Check price → |
| 5 | Dimplex DXFF30TSN 3kW Fan Heater Big rooms and garages | Fan heater | 3,000 W | 79.0p | £47.38 2 hours a day at full power | Dial thermostat | 7.4 | Check price → |
| 6 | Dimplex RUG3TS Rugged Workshop 3kW Fan Heater Workshop tough | Fan heater | 3,000 W | 79.0p | £47.38 2 hours a day at full power | Dial thermostat | 7.2 | Check price → |
| 7 | Dimplex ML3TSTIE7 3kW Convector Heater Big rooms on a schedule | Convector heater | 3,000 W | 79.0p | £71.06 5 hours a day on thermostat | Digital thermostat, weekly schedule | 7.0 | Check price → |
Devola DVPW2500WH Smart Glass Panel Heater 2500W
Digital thermostat, weekly schedule, Wi-Fi, remote
De'Longhi Dragon 4 TRD41025T 2.5kW
Dial thermostat, timer
Dreo Smart Whole Room Heater 714S
Timer, Wi-Fi
Dimplex ECR24TiFB 2.4kW Oil-Free Radiator with Turbo Fan
Dial thermostat, timer
Dimplex DXFF30TSN 3kW Fan Heater
Dial thermostat
Dimplex RUG3TS Rugged Workshop 3kW Fan Heater
Dial thermostat
Dimplex ML3TSTIE7 3kW Convector Heater
Digital thermostat, weekly schedule
* Typical use shown under each figure, 30 days, at the Ofgem price cap (26.32p/kWh). Typical means the seller does not publish the power, so we use a typical figure for that kind of appliance. Recalculated every update.
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What size heater for a large room?
| Room | Size | Heater | Per hour | 5 hours a day on thermostat, a month |
|---|---|---|---|---|
| Living room | about 20 m² (215 sq ft) | 2 kW | 52.6p | £47.38 |
| Large living room | about 25 m² (269 sq ft) | 2.5 kW | 65.8p | £59.22 |
| Open-plan or through lounge | about 30 m² (323 sq ft) | 3 kW | 79.0p | £71.06 |
| Very large or poorly insulated | about 40 m² (431 sq ft) | two heaters of 2 kW | £1.05 | £94.75 |
About 100 W per m² in a reasonably insulated room, at the Ofgem price cap (26.32p/kWh). A plug-in heater is limited to about 3 kW on a 13 A socket.
Which type works best in a big room
- 2.5 kW oil filled radiator: silent, steady heat for an evening; the thermostat keeps it off for longer once the room is warm.
- 2.5 kW panel heater with a 7-day timer: heats only when you are in, from the app or a schedule. Wall-mounted, it frees floor space.
- Whole-room fan heater: warms a big room fastest by moving the air; best for a few hours rather than all day.
- 3 kW convector: the most power from one plug for very large or draughty rooms.
Heating a big room for less
- Two smaller heaters at opposite ends heat a long room more evenly than one big one, and you can switch one off.
- Close doors and curtains; a through lounge loses heat to the hall and stairs.
- Mind the sofa: a heated throw (3.9p an hour) lets you keep the room a degree or two cooler.
- Whole house every day? Gas central heating (8.86p per kWh of heat) or a heat pump is cheaper than plug-in heaters: see the cheapest way to heat.
Frequently asked questions
What is the best heater for a large room?
A 2.5 kW oil filled radiator or panel heater with a thermostat and timer for evenings, or a whole-room fan heater when you need heat fast. Above about 30 m², two heaters work better than one.
How many kW do I need to heat a large room?
About 100 W per m² if it is reasonably insulated: 2 kW for 20 m², 2.5 kW for 25 m² and 3 kW for 30 m². Add more for high ceilings, old windows or an outside wall.
How much does it cost to heat a large room with electric heaters?
A 2.5 kW heater costs 65.8p an hour at full power at the price cap. On its thermostat, 5 hours a day, about £59.22 a month.
Can a plug-in heater heat a whole open-plan room?
Up to about 30 m² with a 3 kW heater, the most a 13 A socket allows. Bigger spaces need two heaters on different sockets, or central heating.
Running costs use the Ofgem energy price cap, 1 October to 31 December 2026: average unit rate for electricity paid by Direct Debit (26.32p/kWh, standing charge 54.83p/day) and gas (7.97p/kWh). National averages; your region and tariff may differ. Prices on Amazon change: check the live price before you buy.