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Oil radiator buying guide

Updated: 22 October 2026

You have one cold room the central heating never quite reaches, and amazon.co.uk lists oil filled radiator wattage from 650 W desk units to 2.5 kW towers. An oil radiator buying guide should leave you with a kilowatt band, a control checklist and realistic safety habits before you open a product row. The [oil radiator comparison](/hub/heating/oil-radiator) lines up twelve plug-in models with timers and review counts so you can match a row to the band you choose here. Peter F. checked those listings and public UK sources. There was no lab test. A qualifying purchase can earn a commission at no extra cost to you.

You have one cold room the central heating never quite reaches, and amazon.co.uk lists oil filled radiator wattage from 650 W desk units to 2.5 kW towers.

Our top picks

De'Longhi De'Longhi Dragon 4 TRD40820T (2 kW)

Best overall

De'Longhi De'Longhi Dragon 4 TRD40820T (2 kW)
9.6/10about £149.00
View offer
Pro Breeze Pro Breeze PB-H white (2.5 kW)

Rank 2

Pro Breeze Pro Breeze PB-H white (2.5 kW)
9.2/10about £79.99
View offer
Warmlite Warmlite WL43002YW (650 W)

Best value

Warmlite Warmlite WL43002YW (650 W)
8.6/10about £26.00
View offer
On this page
  1. 1.How oil radiators heat a room
  2. 2.Wattage and room size
  3. 3.Thermostat, timer and smart features
  4. 4.Safety and placement basics
  5. 5.Next step: pick a row

How oil radiators heat a room

An oil-filled radiator is an electric heater with sealed diathermic oil inside metal fins. The element heats the oil. The fins warm the air mainly by convection, with a little radiant heat close up. Nothing is burned, and you do not refill the oil. Warm-up is slower than a fan heater. Many people prefer the fanless hush once the room settles. Clicking as the metal expands, and a brief smell on the first cycles, is common. Ventilate and use a moderate setting for the break-in period in the leaflet. The fins stay hot after switch-off. That residual warmth was still paid for as electricity.

Wattage and room size

A practical UK rule of thumb is about 100 W per square metre for a normal ceiling and reasonable insulation. A draught, a stairwell, a conservatory or a high ceiling often needs about ten to twenty per cent more. In this set, 650 W suits a small study or box room, roughly six to ten square metres. 1.5 kW fits a double bedroom in the mid-teens of square metres. 2 kW is the everyday default. 2.3–2.5 kW, including Pro Breeze and Midea, suits a larger or colder room. If a listing quotes cubic metres, use watts plus your floor area. An amazon.co.uk room-size line is seller text, not a survey of your house. At the October to December 2026 Ofgem average of 26.32 p/kWh, one hour at 2 kW full output is about 53p before the standing charge.
De'Longhi De'Longhi Dragon 4 TRD40820T (2 kW)

Testsieger

De'Longhi De'Longhi Dragon 4 TRD40820T (2 kW)
9.6/10about £149.00
View offer

Thermostat, timer and smart features

The thermostat switches the element off near the set point and on again as the room cools. A lower heat step, once the room is warm, beats leaving 2 kW on high all evening. A 24-hour timer covers a home office before 9 a.m. or a cut after bedtime. The De'Longhi Dragon 4 TRD40820T states a mechanical 24-hour timer. The electronic Dragon 4 states an electronic timer and ECO Plus. Pro Breeze 2.5 kW units and several Russell Hobbs rows include timer wording. The Daewoo 2 kW listing does not state a timer. DREO adds app and voice control, with eco steps down to 800 W, which pays only if you will programme it. If you will never open an app, a dial and a mechanical timer can do the same job for less.

Safety and placement basics

Portable electric space heaters sold in Great Britain fall under retained Regulation (EU) 2015/1188. The efficiency score rewards a thermostat. That is a design rule, not permission to leave a heater unattended. Stand the unit on a flat floor, plug into a wall socket, and keep about one metre from bedding, curtains and clothes. Do not dry laundry on the fins. None of the twelve saved specs shows a bathroom IP rating. Gloucestershire Fire and Rescue Service and Electrical Safety First warn that a coiled extension lead can overheat on a long run. Register the appliance so a recall can reach you, including the 2026 GOV.UK notice on a Kobe 2 kW oil-filled radiator plug. Stop if the plug discolours, smells of hot plastic, or trips the RCD.

Next step: pick a row

Once the wattage band and the timer need are clear, use the comparison and read the row, not only the badge. Persona picks, including who should skip the top pick, are on best oil filled radiator UK.

Common questions

What wattage oil radiator for a 12 m² bedroom?
Twelve square metres at about 100 W per square metre suggests about 1.2 kW. Sellers usually point you to 1.5 kW or 2 kW because a thermostat cycles and a UK room is not a lab cube. The Russell Hobbs 1.5 kW seven-fin model, with a stated 15 m² label, is a sensible match. A 2 kW unit gives headroom if the room is draughty or the door stays open to a cold landing.
What does heating coverage in m³ mean on Amazon?
It is the seller’s volume, length times width times height, rather than floor area. Without the ceiling height you cannot map that figure onto your room. Prefer the wattage and the floor area, adjusted for insulation, over a single amazon.co.uk coverage cell.
Are more fins better than fewer?
More fins spread the surface for a given wattage, which can help the air move a little. Wattage and how the thermostat cycles still decide comfort. An eleven-fin 2.5 kW radiator is overpowered in a small study, and it is heavier to move.
Can I use a 2.5 kW radiator on a normal UK socket?
A 2.5 kW heater on full power draws about 10.9 A at 230 V. That sits within a typical 13 A socket if nothing else heavy shares it. Plug into the wall, avoid a doubtful extension, and expect the plug to warm after a long run on high.
Is ECO mode worth paying for?
An ECO mode that cuts wattage as the room nears the set point can lower the average draw compared with flat 2 kW on high. It is worth it if you use it. It is not worth a large premium if you will leave the highest step on. The electronic De'Longhi Dragon 4 and the DREO listing mention that behaviour. At the same wattage, oil does not undercut a fan heater. That trade-off is on oil filled radiator vs fan heater.

Related pages

How to use an oil radiator

Oil radiator for bedrooms

Oil radiator

Best oil filled radiator UK: room and budget picks

Oil filled radiator vs fan heater: cost, noise, speed

Sources

Public UK sources named below. amazon.co.uk prices, stars and review counts on these twelve listings were taken from the listing files saved on 20 October 2026. Page updated October 2026.

  1. Centre for Sustainable Energy, room heaters (retrieved 20 October 2026)
  2. Ofgem price cap, 1 October to 31 December 2026 (retrieved 20 October 2026)
  3. Devon and Somerset Fire and Rescue Service, heater safety (retrieved 20 October 2026)
  4. Electrical Safety First, portable heaters (retrieved 20 October 2026)
  5. Homebuilding, oil-filled radiator size (retrieved 20 October 2026)
  6. Regulation 2015/1188 Annex II (retrieved 20 October 2026)
  7. GOV.UK, Kobe oil-filled radiator recall (retrieved 20 October 2026)
  8. Energy.org.uk, electric heaters compared (retrieved 20 October 2026)