How many watts does a fan heater use?

By Tom Calder · Figures checked 4 November 2026 · Costs at 26.32p per kWh (Ofgem cap, 1 October to 31 December 2026)

In short

A typical portable fan heater such as Dimplex’s DXFF20TS is 2,000W on full and 1,000W on half. An hour costs 26p to 53p at 26.32p per kWh, on half to full power; once the room is warm the thermostat cuts in and real use is lower.

A kettle coming to the boil beside a microwave and slow cooker in a warmly lit kitchen on a rainy evening

The numbers

Running watts: 1,000W to 2,000W; Dimplex DXFF20TS: 2,000W with half and full settings.
Amps at 230V (most): 8.7A
Energy an hour: 1 to 2 kWh; Half and full power for an hour. Once the room is warm the thermostat cycles, so this is the most an hour can cost.
Cost an hour: 26p to 53p
On a 1kWh power station: 25 to 45 minutes (only 1 of the 7 units around 1kWh we list can supply 2,000W)
On a 2kWh power station: 45 minutes to 1.5 hours

Costs use 26.32p per kWh, the Ofgem price cap's average Direct Debit electricity unit rate for 1 October to 31 December 2026. Your own rate is on your bill; on a fixed or time-of-use tariff it will differ.

How it’s used, and what that costs

Every electric heater turns one unit of electricity into one unit of heat, so at full power a 2kW fan heater costs the same per hour as any other 2kW heater. What differs is how the heat reaches you and how long it runs. Our guide to electric heater safety and running costs works through the costs for a winter evening.

The honest bit

Plug a heater straight into a wall socket, never an extension lead, keep a clear metre around it and don’t leave it on when you go out or go to bed: that is the National Fire Chiefs Council and Electrical Safety First advice in our electric heater safety and running costs guide.

In a power cut: how long a power station would run it

A 1kWh power station: 25 to 45 minutes (only 1 of the 7 units around 1kWh we list can supply 2,000W). A 2kWh power station: 45 minutes to 1.5 hours. These use the same planning method as our power station pages: capacity × 90% usable depth × 85% inverter efficiency, divided by the load plus about 10W the unit uses itself (BLUETTI’s UK formula).

Output matters as much as capacity. The 7 units around 1kWh we list supply 1,500W to 2,000W continuously, and the 6 around 2kWh supply 2,200W to 3,000W, so check a unit’s rated output covers 2,000W before you rely on it.

A power station is a poor way to heat a room: at 2kW even a 2kWh unit lasts well under an hour. An electric blanket keeps a person warm on a fraction of the power. Never bring a barbecue, camping stove or patio heater indoors. Use a gas or paraffin heater only if it is made for indoor use, with ventilation and a working carbon monoxide alarm (NHS).

To size one for everything you’d want to keep running, use the sizer on our power stations comparison.

Common questions

How much does a portable heater cost to run per hour?

At 26.32p per kWh, a 2kW heater costs 26p to 53p an hour, on half to full power. A thermostat lowers the real figure once the room is warm.

How many amps does a 2kW fan heater draw?

At the UK’s 230 volts, amps are watts divided by 230. At 1,000W to 2,000W, that is 4.3 to 8.7 amps while it runs at full power. Plug it into a wall socket, not an extension lead.

Fan heaters compared →Power stations compared, with a sizer →Home backup power sizer →Running a fridge-freezer on a power station →How to lower your electricity bill →Electric heater safety and running costs →Every appliance’s running cost →

Compare: Oil-filled radiator · Electric blanket · Dehumidifier

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