Heater buying guides for UK homes

All electric heaters turn electricity into heat at the same rate, so the cheapest heater is the one that heats only the space you need, for only as long as you need. A 1200W ceramic heater like the K1 costs about 32p an hour at full power and about 16p an hour in typical thermostat use at 26.32p per kWh.

As a rough guide, a 1200W heater suits a room up to about 20 m², such as a bedroom, home office or small living room. For larger or open-plan rooms, use two smaller heaters or a more powerful one.

UK fire-safety advice is to switch off portable heaters when you go out or go to sleep. Choose a heater with tip-over and overheat protection, keep it 1 metre from curtains and bedding, and plug it straight into a wall socket.

A ceramic heater warms up in seconds and is light to carry, so it suits rooms you use for a few hours. An oil-filled radiator takes 20–30 minutes to heat up but holds warmth longer, so it suits rooms heated all day.

Gas costs less per kWh than electricity, so a plug-in heater only saves money when it lets you turn down or switch off central heating in rooms you aren't using.

The Ofenwerk UK team. Running-cost figures use the official Ofgem price cap and we show our sources at the end of each guide.