Everything you need to know about electric boilers

What is an electric boiler?

An electric boiler works by heating water from the mains using electricity. Essentially, it works similar to a huge kettle, the only difference is that the heating element in the boiler is much more powerful, which allows the unit to heat the water almost instantly.

If you are one of the 4 million UK residents that live in an off grid area, or your house is a listed building and has restrictions that don't allow you to use a gas boiler, an electric boiler might be a great option for you.

Just like gas boilers, electric boilers are available in combi and system models. Combis are cheaper and easier to install, as they don't require a separate water storage tank. System (also known as storage) boilers come with a hot water tank that stores hot water until you need it, thus allowing you to heat water with cheaper electricity tariffs.

Economy 7 and Economy 10 are tariffs for electricity during the night, usually between midnight to 7 am or 10 am, depending on the tariff. Programming your boiler to heat water up during the night and storing it for you to use the following day can save you some much-needed money.

Key benefits of having an electric boiler

Zero CO2 emissions during operation

Carbon dioxide emissions from gas heated homes in the UK are a major concern for the government. Electric boilers don’t produce greenhouse gases during operation, which makes them one of the most environmentally friendly heating options available today. Electric boilers are future proof, as boilers fueled by 100% natural gas are likely to be phased out in the near future. In 2025, all new-built homes will need to install a low-carbon emission system, which can include an electric boiler.

Keep in mind that electricity is largely generated by burning fossil fuels in factories, so there is debate about the extent to which electric boilers are carbon free. However, if your electricity supply comes from green energy sources (e.g. solar parks or wind farms), an electric boiler is one of the greenest solutions out there.

Increased efficiency

In terms of energy efficiency, electric boilers are absolute leaders and can be up to 100% energy efficient, meaning that you get out what you put in. Since there is no steam emitting from the boiler, nearly all energy you pay for is transformed into useful heat for your taps and radiators.

Easy and cheap installation

Electric boilers are often cheaper to install than gas boilers and the unit itself is usually two times cheaper than the gas alternative. As electric boilers don’t produce any condensate, they don’t require a flue and the installation is not limited to the outside wall and can be placed almost anywhere. Electric boilers are ideal for small homes, such as studios, because they are silent during operation and can be installed even in the sleeping/living areas.

Enhanced safety

Electric boilers are safer than gas boilers since the latter carry an inherent risk of carbon monoxide leaks - something you can forget about with an electric boiler. For the same reason, electric boilers eliminate the need for gas certifications and regular servicing and you are likely to save on the maintenance costs, as well as yearly boiler inspections. As electric boilers contain little moving internal parts, they are much less likely to break or require costly parts replacement.

Compatible with solar panels

Most electric boilers are compatible with solar panels, which means you can you can use the energy you generate to heat your home and reduce your electricity bills. There are also options like storage batteries that release energy when you need it and solar thermal systems that heat water in the cylinder. For more information about solar panels and their types, please click below.

Things to consider before purchasing an electric boiler

Not as widely available as gas boilers

As electric boilers are still relatively new to the home heating market, there are less brands offering them, meaning there are limited options to choose from. Current market leaders are Electric Boiler Company and Elnur, who offer floor-standing and wall-hung boilers with warranties of 2 years or more.

Not necessarily better for the environment

Most of the UK's electricity is generated from burning fossil fuels, which not only have a negative impact on the environment but also push the price per unit higher and higher. This gives electric boilers a low ErP rating of D and below, as electricity is considered to be a carbon intensive fuel.

Even if your energy provider generates 100% electricity from renewable sources, the fuel overall is still considered carbon intensive. However, as more suppliers shift towards renewable sources of energy, the ErP rating of electricity is likely to improve in the near future.

Higher running costs

Electricity per unit is more expensive than natural gas per unit. However, with recent increases in gas prices, it may be possible that electricity can become more affordable than gas in the years to come, as renewable energy becomes more widely used for electricity generation.

It’s also worth noting that the design of your home has a significant impact on how much you’ll pay to heat it. From the materials used to the number of windows, many factors play a role. Electric boilers work particularly well in insulated properties, which are usually new builds. There are some things you can do to improve your home’s insulation with minimal spending. Click here for some tips.

Low power output

Currently, domestic electric boilers are only available with power outputs of up to 15 kW, which is sufficient to heat a property with a maximum of 9 radiators and one shower, which is most likely a one bedroom apartment or a small house. If you have a larger home, electric boilers do not (yet) come in the appropriate size. You may consider air or ground source heat pumps instead. Vaillant heat pumps come in a variety of installation options and provide great energy savings.

We would advise against choosing an electric combi boiler for a large home with two or more bathrooms, as it may not meet the high hot water demands.

Is an electric boiler the right choice for me?

In conclusion, it is safe to say that electric boilers still have a long way to go before they can compete with gas boilers in terms of power outputs and running costs. Today, electric boilers are worth considering if you live off the gas grid or plan to make use of solar energy.

For the majority of us, it is best to continue using our gas boilers for the time being, as the cost of electricity is almost four times higher than the cost of gas. It is as important as ever to look after your boiler.