Oil-Filled Radiator vs Convector vs Fan Heater: Which to Buy?

Quick answer: all three cost the same per hour for the same wattage, because every electric heater turns electricity into heat at almost 100%. Choose by how you heat: an oil-filled radiator for long, quiet evenings and bedrooms, a convector for a slim heater that warms the air in minutes, and a fan heater for quick bursts in a study or cold room.

Last updated 25 October 2026 · Facts checked by Abdul Aziz

This guide sits in our home heating series, next to what size heater do I need and the oil-filled radiator running cost guide. Every model below is from our electric heaters and radiators ranges.

What is the difference between an oil-filled radiator, a convector and a fan heater?

They differ in how they move heat into the room, not in how much heat they make. The table shows what that means day to day.

	Oil-filled radiator	Convector heater	Fan heater (ceramic or PTC)
How it heats	An element heats sealed oil, which warms metal fins; heat radiates out and rises from the fins	An element warms air, which rises out of the top and pulls cooler air in at the bottom	A fan blows air across a hot ceramic element
Time to feel warm	Slowest: the oil must warm up first	A few minutes	Seconds
After switching off	Keeps giving off heat as the oil cools	Stops almost at once	Stops at once
Noise	Near silent (some models add a boost fan)	Near silent	Always some fan noise
Feel of the heat	Gentle, even, less drying	Warm air layer near the ceiling first	Direct stream of warm air
Size and weight	Bulky and heavy, on castors (the De'Longhi Dragon 4 weighs 17.8kg)	Slim, can often be wall mounted	Small and light
Best use	Long sessions: evenings, bedrooms, home offices	Background heat in small rooms, garden offices	Short bursts, quick warm-ups, under a desk

Weights and features from manufacturer specifications on our product pages, checked 25 October 2026.

Which is cheapest to run?

None of them, per hour. A heater's running cost depends on its wattage and how long it runs, not its type. Electric resistance heaters convert nearly all the electricity they draw into heat, so a 2kW fan heater and a 2kW oil-filled radiator use exactly the same 2kWh in an hour on full power.

Power setting	Cost per hour on full power	Typical heater
1kW	26.3p	Small convector, low setting on most radiators
1.5kW	39.5p	Bedroom oil-filled radiator or ceramic fan heater
2kW	52.6p	Living-room radiator, convector or fan heater
2.5kW	65.8p	Large oil-filled radiator

Cost = kW × 26.32p, the average electricity unit rate under the Ofgem price cap for 1 October to 31 December 2026 (direct debit). Your tariff may differ.

Where the real difference appears is in how long the heater has to run. Three things cut the bill more than the heater type:

• A thermostat. Once the room reaches its set temperature, the heater only switches on to top it up. All the heaters in our comparison below have one.
• Matching the type to the session. For a 20-minute warm-up before you leave the house, a fan heater wins: it is warm at once and you are not paying to heat oil you will walk away from. For a four-hour evening, an oil-filled radiator holds the room more steadily and keeps radiating after its thermostat clicks off.
• The right size. An undersized heater runs flat out and never reaches temperature. Use our heater sizing guide to pick the wattage.

If your home has gas central heating, heating one room with it is usually cheaper again, because gas costs roughly a third as much per kWh. Our running cost guide has the full comparison.

When should you choose an oil-filled radiator?

Choose one when you heat the same room for hours at a time and want quiet, even warmth. That covers most living rooms, bedrooms and home offices.

• It is silent apart from a thermostat click, so it suits sleeping and working.
• The warm oil smooths out temperature swings, so the room feels less stuffy than with blown air.
• It is the slowest to warm up. Use the timer to start it 30 minutes before you need the room.
• Smart models such as the Duux Edge 2kW add a small fan for a faster start, then run silently once warm.

When should you choose a convector heater?

Choose a convector when you want a slim heater that warms a small room in minutes and can go on the wall. It suits garden offices, box rooms and spare rooms that need background heat.

• It is quiet, because it relies on rising warm air rather than a fan.
• Warm air rises first, so feet can stay cooler than head height in a tall room.
• Heat stops as soon as it switches off, so it suits rooms you heat on a schedule rather than all evening.
• The Duux Edge 1kW convector is 6.5cm deep, rated for rooms up to 15m², app controlled and rated IP24 for splashes.

When should you choose a fan heater?

Choose a fan heater for quick, short bursts of heat: warming a cold study before work, taking the chill off a bedroom before bed, or heating your legs under a desk.

• It is warm within seconds and light enough to carry from room to room.
• It always makes some fan noise. Dreo lists the Dreo Atom Core at 40dB, which is quiet for a fan heater.
• Ceramic (PTC) elements limit their own temperature, and good models add tip-over and overheat cut-outs.
• For year-round use, the Dyson Pure Hot + Cool HP00 is a fan heater, cooling fan and HEPA H13 air purifier in one.

What about infrared heaters?

Infrared heaters are a fourth type: they warm people and surfaces directly instead of the air. That makes them the best choice for spaces where warm air escapes, such as conservatories, garages and covered patios. They are less suited to heating a whole closed room. See the Veito Blade Mini (1,200W, IP55) and our infrared and patio heaters.

Which heater should I buy? Our models compared

Model	Type	Power settings	Key specs (maker's figures)	Best for
De'Longhi Dragon 4	Oil-filled radiator	Up to 2,500W, 3 settings	Up to 75m³, 24-hour timer, ECO Plus mode, 17.8kg	Large or draughty living rooms
Dreo DR-HSH010	Oil-filled radiator	800W / 1,200W / 2,000W	9 fins, ECO mode, 24-hour timer, remote, tip-over cut-off	Living rooms
Duux Edge 2kW Smart	Oil-filled, fan assisted	1,000W eco / 2,000W, boost	App, Alexa and Google Assistant, 24-hour schedules	Rooms heated on a schedule
De'Longhi Radia S	Oil-filled radiator	Up to 1,500W, 3 settings	7 fins, room thermostat, anti-frost	Bedrooms and small offices
Dreo OH621	Oil-filled radiator	Up to 1,500W	8 fins, ECO mode, thermostat 5 to 35°C, tip-over cut-off	Bedrooms
Duux Edge 1kW Gen 2	Convector	500W / 1,000W	Up to 15m², 6.5cm deep, IP24, app control	Garden offices, small rooms
Dreo Atom Core	Ceramic fan heater	900W to 1,500W	Up to 18m², 40dB, 70° oscillation, child lock	Quick warmth in a study or bedroom
Dyson HP00	Fan heater and purifier	Thermostatic	HEPA H13 filter, heats and cools, 70° oscillation	All-year use, allergy sufferers

Specs from manufacturer listings on each product page, checked 25 October 2026. Room coverage figures are the maker's own and assume good insulation.

How to choose in 5 steps

1. Decide how long you heat. Hours at a time: oil-filled radiator. Under an hour: fan heater. A small room on a schedule: convector.
2. Size it. Floor area × 70 to 100W per m², depending on insulation (see our sizing guide).
3. Check noise. For bedrooms, pick a heater with no fan, or one with a quiet mode.
4. Insist on a thermostat, timer and tip-over cut-off. They save money and make the heater safer.
5. Plan the socket. Plug the heater straight into a wall socket, never an extension lead, and keep it at least 1 metre from curtains, bedding and furniture, as Electrical Safety First advises.

Frequently asked questions

Is an oil-filled radiator cheaper to run than a fan heater?

Not per hour. A 2kW oil-filled radiator and a 2kW fan heater both use 2kWh an hour on full power, about 52.6p at the October to December 2026 price cap. The radiator can work out cheaper over a long evening because it keeps radiating after its thermostat switches off, while a fan heater suits short bursts.

Which heater warms a room the fastest?

A fan heater, then a convector, then an oil-filled radiator. A ceramic fan heater blows warm air within seconds. A convector warms the air in a few minutes. An oil-filled radiator has to heat its oil first, so it is the slowest to start but the most even once it is warm.

Which type of heater is quietest for a bedroom?

An oil-filled radiator with no fan, or a convector, because neither has moving parts. You may hear a click from the thermostat and faint ticking as the metal warms. Fan heaters always make some noise; Dreo lists the Atom Core ceramic heater at 40dB, about the level of a quiet library.

Can I use a convector heater in a bathroom?

Only a model rated and installed for it. Free-standing plug-in heaters are not intended for bathrooms. The Duux Edge 1kW convector is rated IP24 for splashes and can be wall mounted, but bathroom heaters must sit in the right zone and be fitted by a qualified electrician, away from sockets near water.

Are oil-filled radiators safe to touch?

The fins get hot, but well-designed models keep surface temperatures lower than fan or bar heaters, and most have tip-over and overheat cut-outs. Keep the radiator at least a metre from curtains and bedding, plug it straight into a wall socket and never use it to dry clothes.

Ready to choose? Browse our oil-filled radiators, electric heaters and full heating range, or read our pick of the best electric heaters UK. Standard UK mainland delivery 3 to 5 working days; see the product page for the full price including delivery.

Sources: Ofgem energy price cap, 1 October to 31 December 2026; Electrical Safety First portable heater safety advice; Cornell Cooperative Extension, portable electric heaters (heat per watt is the same for every type); manufacturer specifications on each Elite Store product page.