Electric boilers: the future of space and water heating in your home?

Electric boilers offer a highly-efficient and environmentally-friendly way to heat you home. In this article we deep-dive on the technology so you can make informed decisions.

FD Team
Climate Change
Electric boilers: the future of space and water heating in your home?
    Contents ( - )
  1. What is an electric boiler?
  2. How do electric combi boilers heat ...
  3. Advantages of an electric boiler (o...
  4. Disadvantages of an electric boiler
  5. Cost range for an electric boiler (...
  6. Electric storage boilers: reducing ...
  7. Electric boiler installations
  8. FAQs about electric boilers

With the gas boiler ban approaching in the UK and other regions worldwide, we must look for alternative technologies for central heating and cooling in our homes. As an alternative to gas, an electric boiler is something that, until recently, would have been unthinkable. But thanks to the rapid decarbonization of the electrical grid in developed nations such as the UK, widespread electric boiler adoption is now possible.

What is an electric boiler?

As the name suggests, an electric boiler uses electric elements inside the boiler to heat water rather than the combustion of any gases. Imagine your kitchen kettle, but on a larger (and more efficient) scale.

Then, this hot water is pumped around your home to radiators or underfloor heating systems, as required.

In the UK, around 25 million homes use a traditional gas boiler to heat their homes, but as the climate crisis worsens, action must be taken to decarbonize domestic properties, which accounts for 13-14% of the UK's total carbon emissions.

As an alternative to fossil fuel boilers, an electric boiler has many benefits, but some drawbacks which will be discussed in more detail throughout this article.

How do electric combi boilers heat your hot water and house?

Electric combi boilers are relatively simple technology, which in itself is a benefit. This short video provides an explanation of how an electric boiler works:

Advantages of an electric boiler (over a gas boiler)

  • removes gas completely from your home
  • no risk of a carbon monoxide leak
  • can be fitted anywhere in your home
  • faults can be managed remotely
  • can be controlled by a mobile device
  • energy efficiency - nearly 100% efficient
  • can be powered by renewable energy

To elaborate further on the list above:

  • Simplification of your home: for many, gas and oil boilers provoke anxiety. A gas combi boiler is another layer of complexity in your home; something to go wrong and typically very expensive to fix. Gas safe certificates will become a thing of the past. There's something attractive about removing the worry of mains gas supply from your home altogether. The underlying technology is simple too.
  • No flue or fuel pipes (therefore for be fitted anywhere): with no need for a mains gas supply coming into your home, you also won't need a flue or fuel pipes. The electric combi boiler can be installed anywhere in your home; it doesn't need to be on an external wall. This can hand over space to a homeowner that might have been lost before.
  • Remote fault diagnosis: one of the benefits of being fully electric is its remote diagnosis capabilities. If something goes wrong with your electric combi boiler, the fault can be remotely diagnosed by the company that installed your boiler, rapidly reducing the amount of money you spend on callout fees.
  • Remote mobile app control: most electric combi boilers come with a smartphone application so that you can turn on/off the system using your device.
  • Nearly 100% efficient: with your current type of boiler (whether it's gas, oil tank, biomass, or hydrogen), there is always an element of inefficiency. As such, some of the energy supplied to your home will be wasted in the process of energy consumption (i.e., converting it to heat). With electric boilers, nearly 100% of the electricity supplied is converted into useful energy; this is much higher than an average gas boiler and even an energy-efficient gas boiler. However, this does not necessarily mean they are cheaper to run.
  • Can be 100% renewable: a significant benefit of an electric system (or anything) is that it can be power entirely by renewable energy, cutting your carbon footprint to nearly zero. In the UK, you can switch to a green energy supplier such as Bulb and Octupus, and in the United States, you can opt for a green pricing tariff or similar.

Disadvantages of an electric boiler

  • cost
  • limited to smaller dwellings
  • at risk of power cuts
  • can be disrupted by a fuse failure of other electrical devices in your home
  • your electrical system must be able to cope with 5-15kWh

To elaborate further on this list:

  • Cost: at the time of writing in 2021 in the UK, the price of a unit for electricity (14p/unit) is higher than gas (4p/unit). Electricity price is the main barrier to widespread adoption. However, as countries rapidly scale up their electrical grid supply, there is reason to believe the cost for a unit of electricity will only decrease in the future.
  • It depends on your property type: current technology limits electric boilers to only really be useful in small or medium homes. This is because electric boilers heat water on demand, so a large hot water demand (i.e., two showers, kitchen, and heating demand all at one time) will take a while to respond. If you live in a larger property, you might want to consider two electric boilers or supplementing your electric boiler with another renewable heating system. You can read more about ground source heat pumps, hydrogen boilers, or biomass boilers in our previous stories.
  • Removing gas from your home is likely to make your overall electric heating system much more reliable, but that doesn't necessarily mean it is entirely fault-proof. Typically your boiler will be wired into your fuse box for safety. This presents the possibility that faults with other electrical devices in your home could blow the fuse of your electric boiler. Always consult an electrician on the best installation practices to try to avoid this.
  • Although uncommon, it's also worth stating that a power cut will limit your ability to heat water/ your home (but this isn't necessarily limited to electric boilers, many gas boilers rely on electrical components too!).
  • Finally, although it could not be considered a disadvantage as such, it should be noted that to install an electric boiler, your electrical system in your house must be capable of handling a 5-15 kWs load.

Cost range for an electric boiler (upfront and maintenance)

Electric boilers cost within the range of 1400-2000 GBP, including installation costs in the UK. In terms of ongoing costs, the main cost will be your electricity. You can see from the table below how the average electricity cost compares to the cost of other fuel types in England, Scotland, and Wales:

Fuel - Average Cost in England, Scotland and Wales (pence per kilowatt-hour)

  • Electricity (standard rate) - 16.36
  • Electricity (off-peak economy 7) - 9.76
  • Electricity (on-peak economy 7) - 20.03
  • Gas - 4.17
  • LPG - 7.19
  • Oil - 4.81
  • Wood Pellets - 5.99

Source: the boiler guide

Electric storage boilers: reducing the cost of electricity

An intelligent way of reducing your electricity cost is to install an electric storage boiler. This is like an electric boiler, but instead of heating your water in real-time (i.e., whenever new hot water is required), water is heated and then stored in a water storage cylinder. This storage can either be built-in in some of the newer models or a separate tank.

Although an electric storage boiler is more expensive to buy than an electric boiler, the long-term cost savings could be enormous. This is because different electricity tariffs are available in the UK (and many other nations) depending on when you use the electricity.

With an electric storage boiler, you can heat a full tank of water during the night to be used the next day.

In doing so, you will be charged a much lower rate for your electricity - around 9.76p per kWh for off-peak Economy 7 electricity - instead of the standard daytime rate of around 15-16p per kWh.

Electric boiler installations

In the UK, there still isn't a central organization that promotes electric boiler uptake (like the Ground Heat Pump Association, for example).

Probably the quickest way to find a professional heating engineer for your electric boiler installation near you is to do a google search.

FAQs about electric boilers

What is an electric boiler? An electric boiler passes water over a heating element to heat water that is then used for space and water heating in your home. An electric boiler can form part of an efficient heating solution for your home.

Is an electric boiler worth it? Millions of us have been heating our homes and hot water with gas for longer than we can remember, but with all this talk of gas boilers (central heating boilers) being phased out to meet climate change targets and for people without access to gas, an electric boiler could well be worth considering.

What is an electric storage boiler? An electric storage heater comes with a storage tank (sometimes inbuilt) to store heated water. This has the benefit that you can heat your water during the night (on a lower tariff) and store it for the next day, saving up to 50% on your electricity bills.

What are the Benefits of Electric Boilers? They're cheaper to install than other boilers, very efficient, very quiet, can practically eradicate your carbon footprint from space heating, have no risk of waste gases and carbon monoxide leakage, and minimal annual maintenance requirements and, therefore, a low maintenance cost.

What is the efficiency rating of electric boilers? This results in an efficiency rating of 99% compared to 89%-95% for most central heating boilers (gas).

Where do electric boilers go? Not only is an electric boiler installation cheaper, but they also don't have to be installed on external/outdoor walls like gas and oil units so that you can put them anywhere in your home with access to the electricity supply.