Electric Heater Running Costs UK 2026: What Each Type Really Costs

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Electric heater running costs in the UK come down to one sum: wattage multiplied by hours multiplied by the price of a kilowatt-hour. At the October 2026 price cap rate of 26.32p per kWh, a 2kW fan heater costs 52.6p an hour at full blast, and a 1.5kW oil-filled radiator costs 39.5p an hour.

But those headline numbers are the reason most articles on this subject are misleading. A thermostatic heater does not run at full power for the whole hour - it heats the room, clicks off, and idles. Once you account for that, the same 1.5kW oil-filled radiator costs closer to 20p an hour in a normal room. That gap, between the nameplate figure and the real one, is worth about £120 across a winter, and almost nobody publishes it.

This guide gives you both numbers for every common heater type, the full-winter cost of running one, and the one comparison that actually decides whether a plug-in heater saves you money or costs you a fortune.

The rate these figures use

All the costs below use the Ofgem price cap rate for 1 October to 31 December 2026: 26.32p per kWh for electricity, with a 54.83p daily standing charge. There is no VAT on electricity between 1 October 2026 and 31 March 2027.

If you are on a fixed or time-of-use tariff your rate will differ, so the method matters more than the number: kilowatts x hours x your unit rate in pounds. A 2kW heater for 3 hours at 26.32p is 2 x 3 x 0.2632 = £1.58.

Be careful with figures you find elsewhere. A lot of running-cost pages still quote 24.5p or 25p per kWh, which understates every result by 5-7%.

Electric heater running costs by type and wattage

This is the nameplate cost - what the heater draws when it is actually on, running at full power.

Two things fall out of this table immediately.

The first is that the type of heater barely matters. A 2kW fan heater and a 2kW convector cost exactly the same to run, because every electric resistance heater on the UK market is 100% efficient. All of the electricity becomes heat. There is no such thing as a more efficient bar fire or a more efficient ceramic element - the marketing around this is noise.

The second is that wattage is the only lever on the cost side, and it is not a free one. A 400W panel heater costs a quarter of what a 2kW fan heater costs per hour, but it also produces a quarter of the heat, so in a cold room it simply runs for longer or never reaches temperature at all.

Why the thermostat, not the heater, decides your bill

Here is what the table above does not capture. A heater with a thermostat cycles. It runs at full power to bring the room up to temperature, then switches the element off and only kicks back in when the room drops below the setpoint. Over a typical evening in a reasonably insulated room, a thermostatic heater is actually drawing power for somewhere between 40% and 60% of the time.

That changes the numbers substantially.

The difference between the worst and best rows is £142 across one winter, on the same heater, in the same room. That is what the thermostat is worth.

This is also the honest answer to "which is the cheapest heater to run?". It is not the halogen one or the ceramic one. It is whichever one has a working thermostat and a timer, sized so it can actually reach temperature and then stop. A cheap 2kW fan heater with no thermostat, left running, is the most expensive way to heat a room in Britain: at 5 hours a day for 120 days it costs £315.84.

If you want to know your own duty cycle rather than guess at it, put the heater on a smart plug with energy monitoring for a week. It logs actual kilowatt-hours, which is the only figure that settles the argument. It is the same trick we used to get real numbers for dehumidifier running costs and tumble dryer running costs.

What "1p an hour" heaters actually cost

You will see low-wattage tube and panel heaters advertised as costing "1p an hour" or "pennies a day". At 26.32p per kWh, a heater that genuinely costs 1p an hour draws 38 watts. That is less than a laptop charger, and it is not going to heat a room - those claims usually come from a period when electricity was around 14p, or they quote the lowest setting of a multi-setting unit.

The realistic figures for the low-wattage category:

• A 100W tube heater costs 2.6p an hour, or 63p if you leave it on for a full 24 hours.
• A 400W panel heater costs 10.5p an hour.

Low-wattage heaters have a genuine use - keeping a greenhouse, garage or conservatory above freezing, or taking the edge off a small, well-insulated room. They are not a substitute for heating. If a room is genuinely cold, a 400W heater will run continuously and still lose to the weather, which is worse value than a 1.5kW unit that runs for a third of the time.

Electric heating vs gas central heating

This is the comparison that decides whether a plug-in heater is a smart move or an expensive mistake, and it needs to be made per unit of heat, not per unit of energy.

Electric resistance heat costs roughly three times as much per unit as gas. So as a rule, using electric heaters instead of your central heating makes you poorer.

The exception is the one that matters in practice: heating one room instead of the whole house. If you are in a home office for five hours and the alternative is firing the boiler for the entire property, the electric heater can win. A 2kW electric heater running at a 50% duty cycle for five hours costs about £1.32. Running a gas boiler to heat a whole house for the same five hours is realistically £3 or more, and most of that heat goes into rooms nobody is in.

The rule of thumb: electric heaters win on one room, lose on the whole house. If you find yourself using two or three of them at once, you have crossed the line and the central heating is cheaper.

For anyone weighing up a permanent change rather than a plug-in stopgap, our heat pump running costs guide has the full comparison - a heat pump is the only electric heating that beats gas, because it moves heat rather than making it.

Storage heaters and Economy 7

If you are on an Economy 7 tariff, storage heaters change the arithmetic, because they charge overnight at an off-peak rate typically around 13p per kWh rather than 26.32p.

A 3.4kW storage heater charging for seven off-peak hours uses about 24 kWh and costs roughly £3.09 a night. The same energy at the day rate would be £6.26. That is a genuine halving.

The catch is that Economy 7 raises your daytime rate to pay for the cheap night rate, so it only works if the bulk of your consumption really is overnight. If you top up with a plug-in heater at 4pm because the storage heater has gone cold - which is the classic failure mode - you pay the elevated day rate on top, and the tariff loses money overall.

The cheapest ways to stay warm

The genuinely cheap options are not room heaters at all. They heat the person rather than the space, which is a far smaller volume to raise in temperature.

An electric blanket for the winter costs less than three evenings with a 2kW fan heater, and we break the sums down properly in our electric blanket running costs guide. This is the same finding as our heated airer running costs guide: the low-wattage, close-to-the-body appliance almost always beats the high-wattage one that heats a whole room.

The other cheap win is not spending anything on heat at all. Draughts are the reason a room needs a heater running longer than it should, and draught-proofing costs £30-£100 in materials with a payback usually inside one winter. Fixing draughts lowers the duty cycle of every heater in the table above, which is the compounding version of a saving.

How to cut electric heater running costs

Six things, roughly in order of how much they are worth.

1. Use a thermostat and a timer. Worth up to £142 a winter on a single 1.5kW heater, as the duty-cycle table shows. If your main heating is central rather than electric, the same control logic applies there too - see do smart thermostats save money. If your heater has neither, a plug-in timer or smart plug adds the timer for under £20 and lets you measure consumption at the same time.
2. Heat the room you are in, and shut the door. The whole economic case for a plug-in heater is that it heats a small volume. Leaving the door open removes the advantage.
3. Size the heater to the room. An undersized heater running flat out for four hours costs more than a correctly sized one cycling at 50%.
4. Turn the setpoint down before you turn the heater off. Every degree on the thermostat is worth roughly 5-8% of the heating energy for that room. Dropping from 22C to 20C is a bigger saving than most people expect and is barely noticeable with a jumper on.
5. Draught-proof first. See above - it lowers the running cost of everything permanently.
6. Check it against your meter. Watch your in-home display while the heater cycles. Seeing 2kW appear and disappear on the live reading is the fastest way to understand what your heater is genuinely costing you.

Frequently asked questions

How much does it cost to run an electric heater for 1 hour in the UK?

At the October 2026 price cap rate of 26.32p per kWh, a 2kW electric heater costs 52.6p an hour at full power, a 1.5kW heater costs 39.5p, and a 1.2kW halogen heater costs 31.6p. Those are nameplate figures. If the heater has a working thermostat it will not run at full power for the whole hour - a typical thermostatic heater draws power for 40-60% of the time once the room is warm, so a 1.5kW oil-filled radiator realistically costs 16-24p an hour rather than 39.5p.

What is the cheapest type of electric heater to run?

No electric heater type is cheaper to run than another at the same wattage, because all electric resistance heaters are 100% efficient - every watt becomes heat. A 2kW fan heater, a 2kW convector and a 2kW oil-filled radiator all cost 52.6p an hour when running. What actually varies the cost is wattage, whether there is a thermostat, and whether the heater is sized correctly for the room. The cheapest heater to run is the one with a thermostat and timer that is big enough to reach temperature and then switch itself off.

Does a 2kW heater use a lot of electricity?

Yes. A 2kW heater uses 2 kWh for every hour it runs at full power, which is about a fifth of the daily electricity use of a typical UK household. At 26.32p per kWh that is 52.6p an hour. Running one for five hours a day through a 120-day winter costs £315.84 if it never cycles off - which is why a thermostat matters so much on a heater this size.

Is it cheaper to use an electric heater or central heating?

It is cheaper to use an electric heater only if you are heating one room instead of the whole house. Per unit of heat, electricity costs about 26.32p against roughly 8.86p for gas, so electric heat is around three times more expensive. But heating a single room with a 2kW electric heater for an evening costs about £1.32, whereas running a gas boiler for the whole house over the same period is usually £3 or more. If you are running two or more electric heaters at once, central heating is almost certainly cheaper.

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

A 1.5kW oil-filled radiator costs 39.5p an hour at full power and a 2.5kW model costs 65.8p. In practice oil-filled radiators almost always have a thermostat, and the oil holds heat after the element switches off, so the real duty cycle is usually 40-60%. That puts a 1.5kW model at roughly 16-24p an hour in normal use, or £95-£142 for five hours a day across a winter.

Do "1p an hour" electric heaters really cost 1p an hour?

No. At 26.32p per kWh, a heater would have to draw just 38 watts to cost 1p an hour, which is not enough to heat a room. The claim usually dates from when electricity cost around 14p per kWh, or refers to the lowest setting of a multi-setting heater. A realistic low-wattage tube heater at 100W costs 2.6p an hour, and a 400W panel heater costs 10.5p an hour.

The bottom line

The honest summary of electric heater running costs is that the heater you buy matters far less than how it is controlled. Every electric heater converts electricity to heat at the same rate, so the only variables are wattage, hours, and how much of that time the element is actually drawing power.

At 26.32p per kWh, budget 50p an hour for a 2kW heater at full tilt and roughly 20p an hour for a well-controlled 1.5kW oil-filled radiator in a draught-proofed room. Use one for a single occupied room and it can genuinely beat firing the boiler. Use several, or leave one running with no thermostat, and it becomes one of the most expensive lines on your winter bill.

If you want to know exactly what yours is costing rather than working from a table, our smart meter savings calculator and a week of real readings will tell you more than any average ever will.