Are Electric Heaters Expensive to Run UK?

Current Electric Heater Running Costs UK

The basic calculation is:

Heater power in kW × hours used × electricity unit rate = running cost

At the current Ofgem reference rate of 26.32p/kWh, the simple full-power examples are:

These are full-power cost equivalents. A thermostatically controlled heater may cycle on and off once the room reaches the target temperature, so real-world electricity use can be lower than the continuous full-power examples.

Your actual cost may be higher or lower depending on your tariff, region, payment method, thermostat behaviour and the power setting you use. For the most accurate estimate, use the unit rate shown on your own electricity bill.

The standing charge is not included in these heater-running-cost examples because it is paid for the electricity supply regardless of whether this heater is running.

If you are checking what a heater’s power rating means, see the Electric Heater Wattage Guide UK.

Source: Ofgem — Energy price cap unit rates and standing charges.

Should You Use an Electric Heater?

For short use, targeted electric heat can avoid heating parts of the home that are not being used. But once a 1.5kW or 2kW heater runs for many hours, its low purchase price can be outweighed by electricity consumption.

What Actually Makes Electric Heaters Expensive?

A heater does not become expensive simply because it has a high wattage. It becomes expensive when high power is combined with long runtime.

1. Long daily usage

A 2kW heater running at full power for one hour costs about 53p at 26.32p/kWh. Used for five hours every day, the simple 30-day example is roughly £79 per month.

If the same heater runs for around six to seven hours a day, or your electricity tariff is higher than the Ofgem average, the monthly cost can move towards or above £100.

2. Heating more space than you need

Portable electric heaters are most useful for targeted room heating. Trying to use them as a substitute for whole-home heating can increase total electricity use quickly.

3. Heat loss

If a room loses heat quickly through gaps, draughts, windows or poor insulation, the heater has to operate for longer to maintain the same level of comfort.

See How to Stop Heat Loss in a Room UK if the room warms up but cools down again quickly.

4. Poor control of runtime

Without a thermostat, timer or clear routine, it is easy to leave a heater running longer than necessary. Runtime is one of the easiest variables to control and measure.

Does the Type of Electric Heater Change the Running Cost?

Standard portable resistance heaters do not become dramatically cheaper simply because one is marketed as an oil-filled radiator, fan heater or convector. If two heaters use the same amount of electricity over the same period, their basic electricity cost is similar.

What changes is how they deliver heat and how that affects real-world runtime.

For product-level guidance, see Best Electric Heaters with Thermostat UK.

How to Reduce Electric Heater Running Costs

The fastest way to reduce the cost of direct electric heating is usually to reduce unnecessary runtime rather than replace the heater immediately.

• Heat the room you are actually using.
• Use the lowest comfortable heat setting.
• Reduce obvious draughts and heat loss.
• Use the heater’s thermostat and timer correctly.
• Switch the heater off when the room no longer needs heat.
• Measure or estimate how many hours it really operates.

For the wider strategy, see How to Reduce Electric Heating Costs in the UK and Do Smart Plugs Save Money in the UK?.

When Electric Heaters Can Be Economical

Electric heaters can be a sensible option when the heating job is small and controlled.

• You heat one room rather than the whole home.
• You need warmth for a short period.
• The room retains heat reasonably well.
• You avoid heating empty rooms.
• You control the runtime with a thermostat, timer or routine.

In these situations, the total cost can stay relatively modest because you are paying for focused heat for a limited time.

When Electric Heaters Become Expensive

Electric heaters become costly when several high-cost conditions happen together:

• the heater runs for many hours every day;
• you use heaters across several rooms;
• the room loses heat quickly;
• the thermostat is set higher than necessary;
• the heater stays on when the room is empty;
• you do not know your actual electricity unit rate.

This is when a seemingly small hourly cost turns into a noticeable monthly bill.

Common Mistakes That Increase Your Bill

• Running a heater for six to eight hours a day without checking the cost.
• Heating rooms that nobody is using.
• Ignoring draughts and obvious heat loss.
• Using maximum power when a lower setting is sufficient.
• Leaving thermostats or timers poorly configured.
• Assuming a newer resistance heater will automatically be much cheaper to run.

Most of these problems can be addressed before buying another heater.

Final Takeaway

Electric heaters are not automatically expensive, but they can become expensive quickly when used for long periods.

For one room and short periods, an electric heater can be a practical, controlled option. For long daily sessions — especially in a room that loses heat quickly — electricity use can accumulate rapidly.