Running an electric heater in the UK can still add up quickly — but the real cost depends on its wattage, your electricity unit rate and how many hours you leave it on.
It is not usually the heater itself that makes the bill painful. The biggest cost driver is runtime.
In this guide, you will see the current UK cost per hour using Ofgem’s July to September 2026 electricity price cap figures, what actually drives your bill up, and how to use an electric heater without overspending.
Quick Answer
Using Ofgem’s average Direct Debit electricity unit rate of 26.11p per kWh for 1 July to 30 September 2026, a typical electric heater costs roughly:
- 13p per hour for a 500W heater
- 26p per hour for a 1000W heater
- 39p per hour for a 1500W heater
- 52p per hour for a 2000W heater
Your exact cost may be higher or lower depending on your region, tariff, payment method and whether you are on a fixed deal. For exact calculations, use your own electricity unit rate from your bill.
Source: Ofgem energy price cap unit rates and standing charges, 1 July to 30 September 2026.
At a Glance — Should You Use One?
Use it if:
- You only need to heat one room
- You use it for short periods, such as 1–3 hours
- You want fast, targeted warmth
Avoid it if:
- You leave it running all day
- You are trying to heat multiple rooms
- Your home loses heat quickly through draughts, thin windows or poor insulation
For the wider cost context, see our guide to electric heater running costs in the UK.
Most people do not overpay because they chose the “wrong” heater. They overpay because the heater runs for longer than they realise.
Electric Heater Running Cost UK
For the current Ofgem price cap period, the average Direct Debit electricity unit rate is 26.11p per kWh. The simple formula is:
Heater wattage in kW × hours used × electricity unit rate = running cost
Real Cost Per Hour
| Power | Approx. cost per hour | Approx. monthly cost at 5h/day |
|---|---|---|
| 500W | ~£0.13 | ~£20 |
| 1000W | ~£0.26 | ~£39 |
| 1500W | ~£0.39 | ~£59 |
| 2000W | ~£0.52 | ~£78 |
The key takeaway: a heater does not become expensive only because of its wattage. It becomes expensive when it runs for too many hours.
If you only use it for 1–2 hours, it can be a practical short-burst option. If you leave it on for 6–8 hours a day, the monthly cost can rise quickly.
For a future calculator reference, keep this inactive until the calculator page is live: reduce electric heating costs.
Cost Reality: What Most People Get Wrong
Using the July to September 2026 average Direct Debit electricity rate, running a 2000W heater for 5 hours a day costs roughly £78 per month.
That is lower than older estimates based on higher unit rates, but it is still a meaningful monthly cost for a single appliance.
If the same heater runs for around 6–7 hours a day, or if your tariff is higher than the Ofgem average, the cost can move towards or above £100 per month.
This is why runtime matters more than almost anything else.
Which Type of Electric Heater Is Best?
No standard electric heater is dramatically cheaper by design if it uses the same amount of electricity. Most portable electric heaters convert electricity into heat at a similar basic efficiency.
What changes is how the heater feels in real use:
- how quickly it warms the space
- how evenly it spreads heat
- how long the room stays comfortable after it switches off
- how long you need to run it
Quick Comparison: Real Use, Not Just Specs
| Type | Best for | Heat style | Running behaviour | Verdict |
|---|---|---|---|---|
| Oil-filled radiator | Bedrooms and longer sessions | Slow and steady | Retains warmth after switching off | Good for controlled longer use |
| Ceramic fan heater | Small rooms and quick heat | Fast and direct | Cools quickly after switching off | Best for short bursts |
| Convector heater | Occasional use | Moderate background warmth | May need longer runtime | Simple budget option |
For product-level guidance, see our editorial guide to the best energy efficient heaters UK.
What Actually Makes Electric Heaters Expensive
Electric heaters are simple, but they become expensive under specific conditions.
1. Long daily usage
This is the biggest cost factor. A 2000W heater used for one hour is not the problem. A 2000W heater used for many hours every day is where the bill starts to climb.
2. Heating the wrong space
Electric heaters are best for targeted room heating. They are usually a poor choice if you are trying to heat several rooms at once.
3. Heat loss
If the room loses heat quickly through gaps, draughts, windows or poor insulation, the heater has to run for longer to keep the space comfortable.
4. No control over runtime
Without a timer, thermostat or clear routine, it is easy to leave a heater running longer than needed.
The Smart Way to Reduce Costs
Most people try to reduce heating costs by replacing the heater first. That is not always the best move.
The fastest way to reduce the cost of an electric heater is to control how long it runs.
A timer, thermostat or smart plug can help prevent the most expensive mistake: leaving the heater on after the room is already warm enough.
The aim is simple: heat the room you are using, for the shortest sensible time, without wasting electricity on empty rooms or unnecessary runtime.
When Electric Heaters Are Actually Cheap
Electric heaters can be a sensible option in the UK when they are used for short, targeted heating.
They work best when:
- You heat one room only
- You use the heater for short periods
- You avoid heating rooms you are not using
- You control the runtime with a timer or thermostat
In these cases, an electric heater can be practical because you are paying for focused heat rather than heating the whole home.
When They Become Expensive
Electric heaters become costly when:
- You run them for many hours every day
- You use them across multiple rooms
- Your home loses heat quickly
- You do not control usage with a timer, thermostat or routine
This is when the hourly cost turns into a noticeable monthly bill.
Common Mistakes That Increase Your Bill
- Running heaters for 6–8 hours daily without checking the cost
- Heating empty rooms
- Ignoring draughts and heat loss
- Using maximum power when a lower setting would be enough
- Not using timers, thermostats or smart control
Most of these mistakes can be fixed without buying a new heater.
What Type of Electric Heater Makes Most Sense?
The best choice depends less on marketing claims and more on how you plan to use the heater.
Oil-filled radiator
Best for longer, steadier sessions where you want gentler background warmth. It can feel more stable than a fan heater, but the running cost still depends on wattage and time used.
Ceramic fan heater
Best for fast, short bursts of heat in a small room. It is usually not the best choice for all-day heating because it cools down quickly after switching off.
Convector heater
Best for simple occasional use. It can be affordable to buy, but it may need longer runtime in colder or draughtier rooms.
For a commercial comparison, use the dedicated guide: best energy efficient heaters UK.
Final Recommendation
Electric heaters are not automatically expensive, but they become expensive very quickly when used for long periods.
If you only need to heat one room for short periods, an electric heater can be a practical and controlled option.
If you are running it for hours every day, especially in a draughty room, it can become one of the more expensive ways to stay warm.
The best strategy is simple:
- Use electric heaters for targeted room heating
- Limit runtime
- Reduce heat loss first
- Use timers, thermostats or smart control where safe and suitable
For buying guidance, continue with our guide to the best energy efficient heaters UK.
FAQ
Are electric heaters cheaper than gas in the UK?
Gas is usually cheaper per kWh than electricity, but an electric heater can still make sense for short, targeted heating in one room. It becomes expensive when used for long periods or across multiple rooms.
How much does a 2000W heater cost?
Using Ofgem’s average Direct Debit electricity unit rate of 26.11p per kWh for 1 July to 30 September 2026, a 2000W heater costs about 52p per hour. Your exact cost depends on your own electricity tariff and how long you use it.
Is it cheaper to leave an electric heater on low?
Not automatically. The cost depends on the total electricity used over time. A lower setting can help if it reduces energy use, but leaving the heater on for longer can cancel out the saving.
Do smart plugs save money with electric heaters?
They can help reduce unnecessary runtime by switching a heater off automatically. However, only use a smart plug if it is suitable for the heater’s power rating and follows the heater manufacturer’s safety instructions.