When I first switched to an electric boiler, one of my biggest questions was: how much is electric boiler cost per month? I wanted the warmth and efficiency without dreading the energy bill.

So I tracked my usage, dug into the data, and compared my findings with real-world figures across the UK.

If you’re thinking of making the same move or simply curious about electric boiler monthly costs, this guide is for you.

What Is an Electric Boiler and How Does It Work?

An electric boiler heats water using electricity instead of gas.

It can supply hot water for both radiators and taps in the same way a traditional gas boiler does — just without the emissions.

Types of Electric Boilers

• Combi Electric Boiler: Heats water on demand — great for small homes.
• System Boiler: Uses a hot water cylinder for storing heated water.
• Storage Electric Boiler: Heats water during off-peak hours (e.g. Economy 7) and stores it for later use.

Electric boilers are popular in flats, small homes, or areas without access to a gas supply. They’re also seen as a greener alternative, especially when powered by renewable electricity.

What Factors Affect the Monthly Cost of an Electric Boiler in the UK?

Several elements influence how much you’ll pay to run your electric boiler.

1. Property Size and Radiator Count

A one-bedroom flat needs far less energy than a four-bedroom detached home. More radiators mean more hot water — which means higher usage.

2. Insulation and Energy Efficiency

If your home is poorly insulated, your boiler has to work harder to maintain warmth. That’s money slipping through the cracks — literally.

3. Your Electricity Tariff

This is a big one. The average UK electricity price (as of 2025) is around 28p per kWh, but that varies. With an Economy 7 tariff, you might pay less overnight — around 12p per kWh during off-peak hours.

What Is Economy 7 and Is It Worth It?

If you use your heating mostly at night or can schedule it cleverly, Economy 7 can save you hundreds per year. My system runs mostly between 11pm and 7am, and the savings are real.

4. Boiler Size (kW Rating) and Usage Habits

Boilers typically range from 6kW to 15kW. The higher the rating, the more power it consumes. If you like your home toasty warm and your showers long, your bills will reflect that.

How Much Does an Electric Boiler Cost Per Month in 2025?

Monthly Running Cost Estimates (UK Average Electricity Rates)

Home Size	Boiler Size (kW)	Estimated Monthly Cost
1-bed flat	6–9 kW	£70–£95
2-bed terraced house	9–12 kW	£95–£135
3-bed semi-detached	12–15 kW	£130–£180
4-bed detached	15 kW+	£170–£250

How Much Electricity Does an Electric Boiler Use Per Month?

On average, a UK household using electric heating may consume 300–600 kWh/month in winter.

For example, a 9kW boiler running 4 hours per day:

• 9 kW × 4 hrs/day × 30 days = 1,080 kWh/month
• At 28p per kWh → £302.40/month

If you’re on Economy 7 and time usage well, this could drop to around £160/month.

How Much Does It Cost to Run a Boiler Per Day?

Daily costs depend on your setup, but here’s a rough idea:

Boiler Size	Daily Usage (4 hrs)	Daily Cost (Standard Rate – 28p/kWh)
6 kW	24 kWh/day	£6.72/day
9 kW	36 kWh/day	£10.08/day
12 kW	48 kWh/day	£13.44/day

You can slash this if you’re on an off-peak tariff or heat less frequently.

My Own Electric Boiler Bill: A Real Example

I live in a 2-bed home with a 9kW electric combi boiler. I’m on an Economy 7 tariff and use a programmable thermostat.

My average winter bill comes in at around £120/month, with summer usage dropping to just £40–£50/month when the heating’s off.

Do Boilers Use a Lot of Electricity?

Electricity Consumption by Boiler Size

Boiler Size	Power Draw (kWh/hr)	Monthly Cost Estimate (4 hrs/day)
6 kW	6	£120–£140
9 kW	9	£160–£200
12 kW	12	£200–£260
15 kW	15	£250+

Yes — electric boilers can use a lot of electricity, especially during colder months.

But their efficiency (often near 100%) means no energy is wasted through flues or combustion like in gas systems.

How Does Electric Boiler Running Cost Compare to Gas?

Fuel Type	Unit Price (2025)	Efficiency	Monthly Cost (Average 2-bed Home)
Gas	~8p per kWh	85–90%	£70–£100
Electricity	~28p per kWh	100%	£95–£135

Gas is still cheaper to run on a monthly basis. But if you don’t have a gas connection — or want to cut emissions — electric is the next best thing.

Discover more on how long does it take to fit a new boiler

How Can I Lower My Electric Boiler Heating Costs?

Here’s what I personally do to keep costs manageable:

• Use a smart thermostat to control when the boiler switches on/off
• Schedule heating during off-peak hours (if on Economy 7)
• Insulate your home – roof, walls, floors, and windows
• Keep radiators clear to allow efficient heat circulation
• Lower thermostat by 1°C – saves around 10% on bills

Conclusion: Is an Electric Boiler Worth the Monthly Cost?

From my experience, an electric boiler can be affordable if you manage your usage smartly and take advantage of off-peak rates.

While it’s not the cheapest option on the market, it’s low-maintenance, highly efficient, and environmentally friendlier than gas.

For smaller, well-insulated homes — especially without a gas connection — I believe it’s a solid investment.

Just be mindful of your tariff, insulation, and heating habits, and you’ll keep monthly costs under control.

Related Article: Why Does My Boiler Keep Losing Pressure?

FAQs – Answering Common Questions About Electric Boiler Cost Per Month

1. Is an electric boiler cheaper than gas monthly?

No — gas is still cheaper per kWh, so gas boilers usually win on monthly cost. But electric boilers are cleaner and easier to maintain.

2. How much electricity does an electric boiler use per hour?

• A 9kW boiler uses 9 kWh per hour
• Cost per hour: £2.52 at 28p/kWh

3. Do electric boilers work well with Economy 7?

Yes — especially storage or system boilers that can heat water during cheap overnight hours.

4.Are electric boilers suitable for large homes?

They can be — but you’ll need a higher kW unit (15kW or more), which increases both installation and running costs.