ENERGY · RUNNING COSTS

What an oil-filled radiator costs to run

On the price cap from 1 October to 31 December 2026, a 2 kW oil-filled radiator at full power costs 52.6p an hour, in Great Britain on average and paying by Direct Debit. Put in your own model and region below.

Your region
Today's cap
Real models

An hour at full power

52.6p

At 26.32p a kWh: the cap's Great Britain average on Direct Debit, 1 October 2026 to 31 December 2026.

Each time: £1.05
A week: £7.37
A month: £32.03
A year: £384.30

The working

2 kW for 2 hours uses 4 kWh at full power.
4 kWh × 26.32p a kWh (Great Britain average, Direct Debit, VAT included) = £1.05 each time.
7 times a week is £7.37; × 52.14 weeks = £384.30 a year, or £32.03 a month.

The standing charge (54.83p a day here) isn't in these figures: you pay it whatever you run. On Economy 7 or another time-of-use tariff, the cost depends on when it runs and your supplier's rates.

Real models

Ratings from each maker's or retailer's page. Great Britain average, Direct Debit.

Model	Rating	An hour
De'Longhi Radia S 1.5kW Oil Filled Radiator (TRRS0715)	1.5 kW	39.5p
De'Longhi Radia S 2kW Oil Filled Radiator (TRRS0920)	2 kW	52.6p
De'Longhi Dragon 4 Oil Filled Radiator 2kW with electronic timer (TRDX40820E)	2 kW	52.6p
De'Longhi Dragon 4 Oil Filled Radiator 2.5kW (TRDSX41025E.WB)	2.5 kW	65.8p

Where you live

A 2 kW oil-filled radiator at full power, on Direct Debit. The Great Britain average is 27.80p a kWh paying on receipt of a bill, and 25.52p on prepayment.

Region	A kWh	An hour	A year
Great Britain average	26.32p	52.6p	£384.30
Eastern England	26.61p	53.2p	£388.55
East Midlands	25.36p	50.7p	£370.19
London	26.60p	53.2p	£388.30
Merseyside and North Wales	27.86p	55.7p	£406.79
West Midlands	25.60p	51.2p	£373.81
North East England	25.46p	50.9p	£371.65
North West England	26.49p	53p	£386.74
Southern England	26.47p	52.9p	£386.41
South East England	26.88p	53.8p	£392.44
South Wales	26.55p	53.1p	£387.69
South West England	26.58p	53.2p	£388.10
Yorkshire	25.60p	51.2p	£373.80
South Scotland	26.11p	52.2p	£381.15
North Scotland	26.35p	52.7p	£384.66

A year is 2 hours a day, every day: my assumption, so put in your own use above.

Or the central heating

A kWh of heat in the room from each.

Heated by	A kWh of heat	2 kW of heat for an hour
An electric room heater (100% in SAP)	26.3p	52.6p
A gas boiler fitted in England since April 2018 (at least 92%)	8.7p	17.3p
A condensing gas boiler from 1998 or later (84%)	9.5p	19p
A non-condensing gas boiler from 1998 or later (74%)	10.8p	21.5p
A gas boiler from before 1998 (66%)	12.1p	24.1p

At the cap's Great Britain average on Direct Debit: electricity 26.32p and gas 7.97p a kWh. The government's home energy rating (SAP) counts an electric room heater as 100% efficient, a kWh of heat for each kWh of electricity, and a gas boiler at its own efficiency, so a kWh of the boiler's heat costs the gas rate divided by that. The older boilers' figures are the ones SAP uses when a boiler's own isn't known; 92% is the least a gas boiler fitted in England since April 2018 must reach.

This is the price of the heat alone. Warming one room with a heater and heating the whole home with the boiler are different questions, and how much heat each room needs isn't something I can price.

A gas boiler fitted after 2005 is most likely a condensing one. Another sign is a plastic flue, and a plastic pipe from its base through the wall to a drain. (Energy Saving Trust, Boiler types explained (last updated 20 May 2026))

The advertising rules' guidance on plug-in heaters says gas is cheaper than electricity at present (citing the Energy Saving Trust) and that, for heating a single room, a single central heating radiator would likely be cheaper to run. It also says ads shouldn't suggest a plug-in heater is an efficient alternative to central heating. (CAP advice, Electric plug-in heaters)

What it uses

The power in watts or kilowatts on the label on the radiator, in the manual or on the maker's site. It's the top setting; the specifications often list the lower ones too.

Does it always use this much? No. A room thermostat holds the set temperature, lower settings draw less than the rating, and the oil keeps giving off heat for a while after the radiator switches off. De'Longhi's 2,000 W Dragon 4 (TRDX40820E), for one, has a lowest setting of 900 W.

Spending less

Try not to run portable heaters for long periods: they usually cost a lot more than central heating or storage heaters. (Citizens Advice: Save money heating your home)
A higher temperature setting won't warm the room faster. It just uses more energy to make it hotter, so try setting it 1 degree lower. (Citizens Advice: Save money heating your home)
The more power an oil-filled radiator uses, the faster it heats the room: a lower setting draws less an hour but heats more slowly. (Which?: Best oil filled radiators)

Questions

How much does an oil-filled radiator cost to run?

A 2 kW oil-filled radiator at full power costs 52.6p an hour at the price cap's 26.32p a kWh (Great Britain average, Direct Debit, from 1 October to 31 December 2026). For 2 hours a day, every day, that's £384.30 a year. The calculator above takes your own model, use, region and how you pay.

Do oil-filled radiators use a lot of electricity?

They use their rated power while heating: the models Which? lists run from 800W to 2.5kW. A thermostat cuts that once the room is warm. In Which?'s tests they cost less an hour to run than fan and convector heaters, and warmed the room more slowly.

Are oil-filled radiators cheaper than fan heaters?

By the hour, in Which?'s tests: on average they cost less an hour to run than fan heaters and convector heaters, but took longer to warm the test room.

Do oil-filled radiators stay warm after you switch them off?

Yes. Which? typically got about half an hour more heating before the room started to cool again.