Electric boilers for home heating and hot water

With  gas boilers due to be banned  in new-build homes from 2025, you may be wondering what other heating options are available to you. While you may wish to  consider a heat pump,  you may have also heard about electric boilers. All methods which can help to support the decarbonisation of our home heating.

What is an electric boiler?

An electric boiler does what it says - it simply uses electricity to heat water instead of gas, but many of the parts and functions are the same. They’re particularly beneficial for homes that don’t have a nearby gas supply, of which there are around four million in the UK, and are thought to be a little more environmentally friendly than gas boilers, especially when used alongside solar panels.

Just like gas boilers come as combi, conventional and system varieties, there are different types of electric boilers, too, including direct and storage. In the following section, we will look at what each of these types are and how they work.

Before we do this, it’s worth noting that an electric boiler is different to an electric water heater. The latter is a device that can heat water for taps on demand, but it doesn’t supply the hot water that is used to heat your home.

How do electric boilers work?

As already mentioned, there are two main types of domestic electric boiler. We explain how each one works below.

Direct electric boilers

A direct electric boiler is most similar to a combi boiler in the sense that it heats the water on demand instead of storing it in a tank. The water is heated via an internal heating element that reaches a certain temperature when electricity is applied to it, much like how a kettle works.

This means that cold water enters directly from the mains, without coming through a cold feed tank first, and can be heated to supply both your home’s radiators and taps as and when you need it.

Storage electric boilers

Storage electric boilers work in much the same way as the direct type, but the system has a storage tank that means the water can be stored for use later. The tank can sometimes be built into the boiler, making the unit a little bigger than a direct boiler, or can sometimes be located elsewhere in the house. This is ideal for homes that are a bit bigger and therefore use more hot water.

Are electric boilers better for the environment?

There are loads of benefits of an electric boiler, from cheaper installation to easy maintenance. But are they better for the environment?

While many sites state that electric boilers are better for the environment because they don’t burn natural gas (which is true), natural gas and other fossil fuels are still burned in order to generate some electricity that will be used by the boiler. Even if you're on a 100 per cent green energy tariff with your energy provider, this green energy still goes to the grid to be mixed in with the rest of the electricity before being rolled out to homes and businesses. Being on a green energy tariff is great - the more of us that are on them, the harder energy providers have to work to generate energy in sustainable ways. But it still means that your boiler might be partly using electricity that has been created by burning fossil fuels.

Yet, it’s not all bad news. Electric boilers may partially use sustainable energy, and that there are ways you can create your own green energy to heat your home. These appliances can work in conjunction with solar panels. When this is the case, you know that the energy it uses has been collected in a sustainable way and could mean that your electric boiler is almost emission free and significantly reduces your heating bills.

How much electricity does an electric boiler use?

The amount of electricity your electric boiler uses will depend on the size of the boiler. They’re usually sized in kilowatts (kW), and we’ve included some examples below so you can get an idea of how much electricity you could use to heat your home.

For our calculations, we’ve used the government average of 7.5 hours for the amount of time your heating is on per day. They also state that most people have their heating on for five months (about 150 days).  

Your boiler may use more or less electricity than this if you leave it on for more or less than 7.5 hours a day for 150 days.

Depending on the  size of your boiler, you can figure out approximately how much it can cost to heat your home. Electricity currently costs is based on 14.4 pence per kWh*. This means that you could pay the following:

*Average pricing taken June 2021. Prices in 2022 will be considerably higher due to the changes in price cap and increased costs per kWh.

How to use an electric boiler

As electric boilers are so similar to their gas equivalent, they can be used in much the same way. Most electric boilers will come with a thermostat, that allows you to set the temperature you wish the home to be heated to, as well as a programmer, so you can set a heating schedule that’s suitable for you. This means you don’t have to worry about changing any settings on the boiler itself.

As with a gas boiler, you should continue to regularly check the boiler pressure (this should be around 1.5 bar) and bleed any radiators that have cold spots.

When your electric boiler is installed, be sure to ask the qualified electrical installer anything you’re unsure about. We’re sure they’ll be happy to fill you in with the necessary information.  

Sources:

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/274772/4_Main_heating_systems.pdf