Home  >  Advice Centre   >   Electric Combi Boiler Replacement Guide

Electric Combi Boiler Replacement Guide


For homeowners who are not connected to the gas grid, an electric boiler comes as a no brainer. Most homes are connected to power, and it saves you the trouble of having to LPG or oil storage tanks for your new boiler.

Going for the combi option is also a relatively easy decision. Combi boilers are practical and efficient and most importantly operate quietly to keep your home warm and give you a steady supply of hot water.

Considering these two factors, it’s easy to see why electric combi boilers are a popular choice where gas varieties cannot make it.

While the decision on using an electric combi boiler might come easy, the work involved in research and understanding the aspects of installing the new boiler is the same as with other boilers. With this guide, you can ease the task and get all the information you need in one place.

What is an Electric Combi Boiler?

As the name suggests, electric boilers use electricity as a source of power to produce heat for heating water in the same way as a gas boiler. The heat produced by the boiler can be used to warm the radiators and consequently the house and you also get hot water from kitchen taps and in the bathrooms.

Electric combi boilers come in various shapes and sizes designed to suit the needs and size of different households. Regardless of the size or power, the functioning is the same. Ideally, electric boilers work the same way that electric kettles work only at a higher capacity.

How Much Does an Electric Combi Boiler Cost?

As noted earlier, electric combi boilers come in different sizes. The bigger the boiler (or, the higher the capacity), the more you will pay for it. A 9kW model will set you back in the region of £1,500. Needless to mention, a smaller boiler will also cost you less in maintenance. The downside with small boilers is they are not as efficient as the larger varieties.

A larger electric combi boiler can cost as much as £2,500. There are also premium models built for longevity with a broad range of features. While these will last longer, be more efficient and offer more features, they have a higher price tag and can cost up to £4,500.

The electric boiler market is no longer a small market. It’s aggressively growing and there are plenty of boilers to choose from depending on your budget and size of your home. To help make the task of finding the right boiler for you easier, here is a table detailing how much different electric combi boiler costs and the different power ratings.

In addition to the cost of the boiler, you should also factor in the price of installing the boiler, which is also significant. However, the cost of boiler installation or replacement is never the same. Various factors affect the cost of installation among them the type of boiler, the extent of boiler work required and the size of your home.

Compare the Boiler Market can provide you with up to 4 FREE quotes from different installers in your area with no obligation to help you come up with an accurate budget.

Are Electric Boilers Cheaper than Gas?

At face value, it seems like electric boilers are more expensive to run than their gas-powered counterparts. This is because the UK relies heavily on fossil fuels to produce most of its electricity.

However, a closer look reveals that while electricity is more expensive, there are tons of other areas that you can save money when using electric boilers.

For instance, with electricity boilers, you don’t need to worry about the annual maintenance or safety inspections that come with gas boilers. That is one area where you get to save money.

Additionally, electric boilers are cheaper to install, which take up a substantial size of your budget.  You also don’t have to pay for an annual gas certificate when using an electric boiler. Electric boilers are also more reliable and fail less often. Efficiency ratings also show that electric boilers are more efficient than their gas counterparts.

With the government advocating for green investments, you might find it cheaper to have an electric boiler for your home as opposed to gas boilers.

On the surface, Gas boilers are cheaper to run than electric boilers. However, after considering all the different areas you can save money using electric boilers and the fact that you don’t need annual servicing or gas certificates, the odds look to be piling up in favour of the electric boilers.

What are the running costs of Electric Combi Boilers?

On average, an electric combi boiler will cost about £1,800 to run per year. For higher capacity models, the running cost per year can go as high as £2,025. This is assuming the boiler uses 13,500kWh with the average price of electricity per kWh at 15 pence.

Electric Combi Boiler Types

Choosing the right electric combi boiler goes a little further than most boilers. In addition to the power rating of the boiler, there are also a few different types of electric combi boilers that you have to sift through before you can settle on your preferred option.

Storage Electric Boilers

This type of electric boiler comes with a hot water tank built into the unit or separately. These types of electric boilers allow you to manoeuvre around the electricity rates and heat your water when the rates are lower. However, the extra tank will take up more space during installation, not to mention you might have to stretch your budget slightly when considering this option.

Direct Acting Electric Boiler

There are no tanks involved here. This is the simplest type of electric combi boiler in the market. Expectedly, it’s much cheaper but doesn’t offer you as much convenience as some of the other models. In this boiler, a heating element heats the water using electrical resistance. The boiler only heats water on demand. Without storage, you can’t take advantage of low night-time tariffs.

Electric CPSU

When it comes to electric boilers, the amount of hot water you can heat is limited. The Combined Primary Storage Unit boilers are designed to overcome this challenge. This type of electric combi boiler can hold loads of water. It heats large amounts of water quickly. The boiler can handle high pressure resulting from handling large volumes of water at a time. The CPSU boilers are best suited for large homes and commercial properties with a high appetite for hot water.

Dry Core Storage Boiler

The Dry Core boiler uses the same principle as the storage electric boilers. At night, the heater warms up bricks that retain heat. During the day, the heat is released into the water on demand. The hot water is then used in the same way as with other types of boilers.

Solar Compatible Electric Boilers

In a bid to remain energy efficient, there are electric heaters that are compatible with solar energy. These work in homes that have an immersion heater. The solar panels installed on the home heat up during the day and store the energy which can be used to power the heater instead of using electricity. This type of boiler also allows you to leverage on the lower night-time electricity rates. 

What is the Best Electric Combi Boiler?

The Comet by EHC

EHC is one of the most reputable electric boiler manufacturing companies. The comet is their most popular model.

The boiler offers storage of up to 140 litres to keep up with the demands of the home. You also get to choose from multiple power ratings suited for different homes. These include 9kW, 12kW or 14kW.

While the comet is affordable, it features premium parts like a stainless-steel heat exchanger. It also proves to be very efficient and easy on your pockets with a 100% energy efficient rating. The 2-year standard warranty will have you resting easy after making the purchase.

Electromax by Heatrae Sadia

Heatrae Sadia is an extension of Baxi Heating – one of the largest heating companies in the UK. Electromax comes with a hot water storage with a capacity of 180L and comes pre-plumbed with a factory fitted circulating pump.

The boiler comes in two varieties: 6kW and 9kW, which are perfect for domestic applications. With a 99.8% rating, you don’t need to worry about electricity bills drilling holes into your pockets.

Mattira MAC15 by Elnur

If you’re looking for an option that offers multiple varieties, the Mattira MAC15 could be the best option for you. It comes with power outputs of 3kW all the way 15kW in single and 3-phase supplies.

The boiler pairs its 50 litres water storage with a draw rate of 12 litres per minute. The hi-tech adjustable temperature regulation can provide instant hot water. It is a regular boiler with all the right features and remains affordable.

Advantages of an Electric Combi Boiler

The higher running costs of electric boilers might leave reconsidering your decision to get a new electric boiler. But there are a variety of benefits that come with electric boilers that you will find interesting:

No gas or oil needed

Electric combi boilers are an excellent alternative for homes that are not connected to the gas network and don’t have space for an oil tank. If you have electricity in your home, you have an electric boiler installed.

Better Efficiency

Electric boilers don’t burn fuel to produce heat. That means they don’t lose energy through waste gases. Electric combi boilers have efficiencies of 99% to 100% while the best gas boilers have about 95% efficiency rating.

Lower Emissions

Since electricity doesn’t release any waste gases, electric boilers are considered a much greener option compared to oil or gas boilers hence more environment-friendly.

Cheaper Installation

Because electric boilers don’t release any gases, there are fewer and less challenging components involved with the installation of electric boilers. Electric boilers don’t need a condensate or flue which reduces the cost of installation drastically.

Flexible Installation

Unlike gas or oil varieties that require to be installed in close proximity to the outdoor walls because of the flue or condensate pipe, the case is not the same with an electric boiler. You have more freedom to choose where you would like to install your new boiler.

No Annual Servicing

Gas and oil boilers need annual servicing, which can cost up to 160 each time. Electric boilers don’t require to be serviced every year which saves you money. However, it’s important to note that the hot water cylinder does need annual servicing even though the heating unit itself doesn’t.

No Carbon Monoxide leaks

Gas and oil boilers produce harmful gases like carbon monoxide as by-products. There are systems to expel the gases, but this could fail, leading to a leak. With an electric boiler, such gases are not produced, so you have nothing to worry about.

Quiet Operation

There are no moving parts in electric boilers. You no longer have to worry about loud clanks and frightening noises coming from your boiler. Electric varieties operate silently.

Solar Compatible

Some types of electric boilers can be incorporated with solar systems. This means the heater can be partially powered by solar energy and partly by electricity, allowing you to save more money.

Lightweight and compact

For wall-mounted varieties, you don’t have to worry about the heater ripping your wall down. Because the boiler doesn’t have the additional weight of flue or condensate pipes, it’s more compact and lightweight opening up more installation options.  

Disadvantages of an Electric Combi Boiler

On the other hand, electric boilers do have some shortcomings as well. Being able to find solutions or decide whether you can cope with the downsides is a critical aspect when determining if an electric combi boiler is the best option for you.

Some of the downsides of an electric boiler include:

Smaller Systems

Typically, electric boilers are not as diverse as gas or oil boilers. They are a little shorthanded and as such, they might struggle to keep up in larger properties.

Higher Running Costs

Electric boilers will typically cost you more in running costs, especially energy costs. It gets worse when you have to use the boiler during the day if you’re on a split tariff.

Power Cuts

If there’s a loss of power and you don’t have a backup that means you lose access to both heating and hot water. However, this problem does not affect electric boilers only. It also affects other boilers since they have electric components as well.

Could Blow the Fuse

Electric boilers use about 48amps. Most homes have a 60 amp fuse. Even though using the boiler alone will not blow the fuse, using a couple more appliances while the boiler is running could easily blow the fuse. You should check with an electrician during the installation.

Combi Boiler Size Calculator

Choosing the right combi boiler for your home requires a careful balance of a variety of factors to identify a boiler with the right output and will keep up with the demands of your home.

If the output is low, the boiler will struggle. If the output is high, you will be paying more in energy bills, yet you don’t use the additional output.

A combi boiler size calculator considers various aspects of your home to help you find the ideal boiler for your home with just enough output to provide you with plenty of heating and hot water.

Some of the factors put into consideration include:

  • The number of bathrooms around the house that don’t have electric showers.
  • The number of radiators in the house.
  • The number of people living in the house.
  • The number of hot water taps.

By analysing these factors, the calculator can recommend the ideal output for your combi boiler, ensuring you get a combi boiler that will satisfy the demand without being wasteful on energy consumption.

It goes without mention, choosing a boiler with the right output for your home will go a long way in reducing the running cost of the boiler while keeping your home comfortable and warm.

Get Free Quotes for a Replacement Today!

Getting accurate prices for a new boiler and the installation cost is a big challenge for every homeowner. The process of boiler replacement is a tedious and financially intensive one that requires careful planning and budgeting.

You can’t budget if you don’t have the correct prices. Compare the Boiler Market can help you get multiple quotes free from up to 4 installers in your areas. All you need to do is fill up a short inquiry, and we will have the installers call you with a FREE quote.

To ensure the quotes are bespoke to your task and accurate, the installer will ask a few questions like the type of boiler being replaced, where you live as well as the amount of boiler work required. If there are any boiler replacement parts needed, the installer will consider the cost of sourcing for those parts as well.

  • Buy Now Pay Later Schemes!
    • Interest Free Credit
    • Buy Now Pay Later
    • Spread Payments
    Finance Options
  • Free Boiler Quotes

    No-obligation to buy!

    • From the comfort of your home
    • You choose the best company
    • Gas Safe trusted companies
    Get Quote NOW
Need a New Boiler

Get FREE quotes from tradesmen in your area today. What are you looking for?