Quick answer
Choose a plug-in heater with a ceramic (PTC) element, a thermostat, and tip-over and overheat cut-offs. A 1200W unit like the Ofenwerk K1 heats a typical UK room of up to 20 m², gives warm air in about 2 seconds, and costs around 16p an hour in typical use.
Quick checklist
- Ceramic (PTC) element for fast, even heat
- Adjustable thermostat
- Tip-over and overheat cut-offs
- Cool-touch casing
- Around 1000–1500W for a typical UK room
- UK 3-pin plug and UKCA/CE marking
- At least 12 months' warranty from a UK seller
What is a plug-in heater?
A plug-in heater is any electric heater that runs from a standard UK 3-pin socket. You don't need any installation, so you can move it to wherever you are. The main types are fan, ceramic, oil-filled, convector and halogen heaters.
Types of plug-in heater compared
| Type | Warm-up | Best for | Watch out for |
|---|---|---|---|
| Ceramic (PTC) | Seconds | Quick, targeted warmth | Gentle fan noise |
| Coil fan heater | Seconds | Occasional use | Burnt-dust smell, glowing coil |
| Oil-filled radiator | 20–30 min | All-day background heat | Heavy, slow |
| Convector | 10–15 min | Larger rooms | Uneven heat |
| Halogen | Instant | Spot heat | Bright glow, hot surface |
What to look for
- Thermostat: holds the temperature so it isn't running at full power all the time
- Tip-over switch and overheat protection, which are essential with children, pets or older relatives
- Cool-touch casing
- Right wattage: about 1000–1500W for most UK rooms
- A UK plug and CE/UKCA marking
- A warranty of at least 12 months
How much does a plug-in heater cost to run?
Multiply the wattage in kW by your unit rate. A 1200W heater at 26.32p per kWh costs about 32p an hour at full power. With a thermostat cycling it on and off once the room is warm, typical use is nearer 16p an hour. Use our running cost calculator to check your own tariff.
Are plug-in heaters cheaper than central heating?
To heat one room for a few hours, often yes. Gas central heating is cheaper per kWh but warms the whole house. If you spend the evening in one room, a plug-in heater lets you turn the boiler down and heat only where you are.
What it costs to run (current UK prices)
At the Ofgem price cap of 26.32p per kWh (1 October to 31 December 2026), a 1200W heater like the K1 costs about 32p an hour at full power. Once the room is warm the thermostat switches the heater on and off, so in normal use it averages about 16p an hour.
| How long | Typical cost per day | Over 30 days |
|---|---|---|
| 1 hour | 16p | £4.74 |
| An evening (4 hours) | 63p | £18.95 |
| A working day (8 hours) | £1.26 | £37.90 |
Your own price may be a little higher or lower depending on your region and tariff. See how we calculate running costs or try the running cost calculator with your own unit rate.
How to pick the right size plug-in heater
A rough guide used by many UK installers is about 100W for every square metre in an average, reasonably insulated room. So a 12 m² bedroom needs about 1200W, and a 20 m² living room needs 1500–2000W if the room is draughty or has high ceilings.
If your room is well insulated, or you only want to take the chill off while you sit in one spot, a 1200W ceramic heater is usually enough. Bigger isn't always better: a 3kW heater costs more than double to run at full power and often gets the room too hot, too fast.
Where to put a plug-in heater
Place it on the floor or a stable table, pointing towards where you sit, not at the window. Ceramic heaters move warm air, so aiming the airflow across the room warms it faster than leaving it in a corner.
Keep it at least a metre from anything that could catch fire, and plug it directly into a wall socket. If your sockets are behind furniture, move the furniture rather than using an extension lead.
Signs of a poor-quality plug-in heater
- No UK plug, or a plug adaptor in the box
- No UKCA or CE mark and no UK company address
- Wattage claims like '3000W mini heater' in a palm-sized case
- No tip-over switch
- Prices far below what similar heaters sell for, with no returns policy
How the K1 compares with other heaters
| Heater type | Warm in | Running cost | Safety and comfort |
|---|---|---|---|
| Ofenwerk K1 (ceramic) | About 2 seconds | About 16p/hour typical | Tip-over and overheat cut-off, cool-touch case, no glowing coil |
| Coil fan heater (2–3kW) | Seconds | 53–79p/hour at full power | Hot coil, can smell of burnt dust, often noisy |
| Oil-filled radiator (1.5–2.5kW) | 20–30 minutes | 39–66p/hour at full power | Surfaces get hot, heavy to move |
| Convector (2kW) | 10–15 minutes | About 53p/hour at full power | Heat rises to the ceiling first |
| Electric blanket (100W) | 10–20 minutes | About 3p/hour | Warms the bed only, not the room |
Full-power costs worked out at 26.32p per kWh. Thermostats lower all of these in real use.
Using any electric heater safely
These tips follow UK fire-service and Electrical Safety First advice and apply to any portable heater, including ours:
- Plug the heater straight into a wall socket. Don't use an extension lead or adaptor; they can overheat.
- Keep it at least 1 metre from curtains, bedding, clothes and furniture.
- Stand it on a flat, hard, stable surface where it can't be knocked over.
- Never cover it or dry clothes on it.
- Switch it off at the wall when you go out.
- Check the plug and cable now and then. Stop using it if either is damaged or feels hot.
- Make sure you have a working smoke alarm on every floor. Many UK fire services fit them free for older residents.
When the K1 is not the right choice
We'd rather you buy the right heater than return ours. The K1 is probably not for you if:
- You want to heat a large open-plan space over about 20 m² with one heater. Two K1s, or a bigger heater, will do a better job.
- You want to replace central heating for the whole house. The K1 heats the room you're in, not every room at once.
- You need total silence. The K1 has a gentle fan sound, a bit like a quiet laptop.
Our pick: the Ofenwerk K1 Heater
- Warm air in about 2 seconds (PTC ceramic)
- 1200W, heats rooms up to 20 m²
- Tip-over and overheat cut-offs, cool-touch casing
- Thermostat + remote, about 16p an hour typical
- Free UK delivery, 30-day money back, 24-month warranty
Frequently asked questions
Are plug-in heaters safe?
Modern plug-in heaters with tip-over and overheat cut-offs are safe when used properly. Plug straight into a wall socket, never an extension reel, and keep at least 1 m from curtains and bedding.
Do plug-in heaters use a lot of electricity?
A 1200W heater uses 1.2 kWh per hour at full power. With a thermostat it uses less once the room is warm.
Are plug-in heaters any good?
Yes, for heating the room you're in. They're not designed to replace whole-house heating.
Can I leave a plug-in heater on overnight?
Only if it has a thermostat, tip-over and overheat protection, and you follow safety advice. Many people warm the bedroom before bed and switch off, which is cheaper and safer. Never cover a heater or put it near bedding.
What is the most efficient plug-in heater?
All electric heaters turn almost 100% of the electricity they use into heat. The savings come from heating only the room you're in, using a thermostat, and choosing the right wattage, not from a special type of element.
Can I plug a heater into an extension lead?
UK fire services advise against it. Heaters draw a lot of current, and extension leads can overheat. Plug straight into a wall socket.
How long does a plug-in heater last?
A good-quality ceramic heater normally lasts several winters. The K1 comes with a 24-month warranty.
Sources and how we checked this guide
- Electricity price: Ofgem: energy price cap unit rates and standing charges, checked 25 October 2026.
- Heater safety: UK fire and rescue service advice and Electrical Safety First guidance on portable heaters.
- K1 figures (1200W, about 2-second warm-up, room size up to 20 m², safety cut-offs) come from the product specification.
- Costs are worked out with the method on how we calculate running costs.