How much does an oil-filled radiator cost to run?
A typical oil-filled radiator costs about £1.05 per evening to run. At 7 evenings a week that is £7.37 a week, or £383.22 a year, based on 1,000 W for 4 hours (4.00 kWh) at 26.32p per kWh.
Adjust for your oil-filled radiator
Worked example
1,000 W is 1 kW. Running for 4 hours uses 1 × 4 = 4.00 kWh. At 26.32p per kWh that costs £1.05.
Seven four-hour evenings a week comes to about £383.22 a year. Using it two hours less each evening would save about £191.61.
How to cut the cost
Every unit of electricity becomes one unit of heat, so the only savings come from using it less: shut doors, use the lowest setting that keeps you comfortable, and use a timer. A heat pump typically delivers around three units of heat for each unit of electricity, which is why it is cheaper to run.
Questions
How much does an oil-filled radiator cost to run per hour?
At an average draw of 1 kW, one hour costs 26.3p at 26.32p per kWh.
Are oil-filled radiators cheaper to run than other electric heaters?
Not on running cost: every electric resistance heater turns one unit of electricity into one unit of heat. Oil-filled radiators keep giving off warmth after they switch off, which suits steady, longer use.
Other appliances
Electricity rate: Ofgem energy price cap, 1 October to 31 December 2026, Great Britain average, Direct Debit, default tariff: 26.32p per kWh. Your own tariff and region may differ, so change the rate above to match your bill. Appliance figures are typical estimates; your appliance's energy label or manual is more accurate. Last checked 2026-11-03. Next review: January 2027, when Ofgem announces the next quarter's cap.