Complete combi boiler installation guide for you

Here is everything you need to know about having a combi boiler installed into your home. In this useful guide we answer the most common questions around a new combi boiler installation, what is a combi boiler? How do combi boilers work? How much do they cost? And also, what the best option for you is.

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What is a combi boiler?

From the top, A combi or combination boiler controls your entire central heating system directly from one, compact unit. Combi boilers are the most sort after type of boiler in the UK with more and more people switching from a conventional or traditional system.

Combi boilers are a perfect option for most homes as they come in a range of sizes and outputs for different size homes. With this type of boiler, you can save much more space than you would with a regular boiler as there is no need for an external water cylinder or water tank. A great thing about combi boilers is that they give you instant and unlimited access to hot water, as you don’t have to wait for a water cylinder to heat the water up.

Combi boilers are also known as the energy efficient option as all modern combi boilers are condensing so they use much more of the energy they produce and less is wasted. Condensing boilers make more use of the energy supplied by extracting heat from flue gasses that would have otherwise been lost by a non-condensing boiler. Combi boilers are usually faster and cheaper to install, as there’s no requirement for a water cylinder, meaning less pipe work is needed.

How do combi boilers work?

Combi boilers work by having one compact system heating both your hot water and radiators so there is no need to have an additional external cold-water tank or hot water cylinder. Combi boilers supply instant hot water, by constantly being on standby when there is no water demand. As soon as you turn on the hot water tap, the boiler will fire up and the water will become hot very quickly. When the request for hot water is trigged by someone turning on the hot tap, this signals the boiler to start heating water inside of the system. The heat exchanger transfers most of the heat from the burnt gas inside the boiler to the cold water, and then gives it to the taps as required.

Inside combi boilers, the control valves operate in contrasting directions to either allow water to flow through the central heating system or divert it to the appropriate hot water tap as required — but never both at the same time. You can pre-set your required temperature and the boiler will work with the room thermostat to ensure your home is heated as you like it to be.

How much does a combi boiler installation cost?

The price of a combi boiler can depend on several things, such as the size of your home and the involvement of the boiler installation.

When someone needs a new boiler, one of the first questions they have is ‘How much will a new boiler cost?’. In the UK, most people replacing their boiler are likely to choose a combi boiler as they are more efficient and greater for saving space in your home.

The cost of the combi boiler itself will be less money than you are quoted for by the installation company as they will add the cost of labour on top of this price. Whilst the cost of installation may seem expensive, it’s important to note that a new boiler should always be installed by a Gas Safe registered engineer who will follow strict checks and procedures. Having an experienced Gas Safe registered engineer ensures peace of mind that the installation has been completed to the highest regulated standards.

There can be a great difference in boiler prices so if you want to know how much a combi boiler costs it’s best to get an online quote for your home. This will consider your current central heating system, the fuel you boiler uses and how many radiators you have in your home to give you an accurate price.

Our prices for a new combi boiler, with installation included are great value for money and we have a range of boiler brands and fuel types available.

The price of a new combi boiler can depend on the brand you choose to have installed but it’s important to remember that you shouldn’t compromise on quality. If the price of a new boiler is particularly low, it’s worth checking to make sure the boiler itself is manufactured to a high standard to avoid additional repair costs in due course.

We only install high quality boilers from highly regarded brands so you have the peace of mind that you are getting the best for your budget. Our boilers come with a manufacturer backed warranty of up to 13 years so you can be postitive of how long lasting they are.

What is the best type of combi boiler for me?

There is a wide range of combi boilers available with a wide choice of brands available. Recommending the right boiler will greatly depend on your home and needs. If you have a lower demand for hot water or a smaller home, then a boiler with a lower output might be more suitable. The higher your hot water demands are, the higher the output of boiler you will need to be installed. As a general guide you can learn what the best combi boiler is for you by considering what your needs are based on size, price and performance.


The size of your home will have a huge influence when deciding what the best combi boiler is for you. Combi boilers are a great choice for a wide range of homes in the UK as they are powerful enough to supply large amounts of instant hot water. However, if you have a very large property with a high demand for hot water then a combi boiler may not be a suitable option.


The price of a combi boiler is a major influential factor when deciding which boiler is best suited for you. It’s important to make sure that a new boiler installation is always performed by a Gas Safe registered engineer. If the price you are being quoted seems too good to be true, it could be that the engineer is not qualified enough which could have huge consequences. To keep price down, you could consider installing the new boiler in the same place as the existing one and avoid purchasing additional factors that are not required.


Different boilers have varied performance levels based the home they are heating. If you have a smaller home, the best combi boiler may be one with a low output performance. This is because the house is smaller, the demands on the boiler for heating and hot water will be reduced. In the same way if you have a larger home, you may require a boiler with a larger output as it will need to provide a more powerful performance in order to supply the demand of hot water required.

If you’re not sure what the best combi boiler is for you then let us help you to choose. With nearly a combined experience of 50 years, you can trust us to recommend the right boiler for you, our easy to use online quote tool will provide you with the best option of boiler for your home.

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