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Boiler Installation: Everything You Need to Know

Adam Cherry
By: Adam Cherry
Updated: 17th May 2022

Boiler Installation: Everything You Need to Know
Fitting a boiler may seem as simple as replacing the old boiler with a new one. However, there are actually several things you'll need to keep in mind that may affect your boiler installation. How long does it take to fit a boiler? Who can install it? We answer these questions and more in this guide to boiler installation.

If you're simply looking for someone to install a boiler for you, you can get free quotes from up to 3 Gas Safe registered heating engineers near you, simply click the link below and answer a few questions.

Boiler installation procedure

When it comes to having a new boiler installed there are different processes depending on how complex or complicated the boiler replacement process is. For example, there are a lot fewer steps to replacing a like-for-like combination boiler than there are for replacing a combi boiler with a system boiler. There are also more steps if you want your boiler fitted in a different location like the loft or a garage.

Find out more here: How much does moving a boiler cost?

Regardless of how complicated an installation is though, there are 3 broad steps that every boiler installation involves.

  1. Removing the old boiler

    Before a heating engineer can begin fitting your new boiler, they will need to remove the old one. You can make this easier for them by clearing the space around your boiler and ensuring they have easy access to it. If your boiler is installed in the attic, it should be accessible via a set of stairs and a safe walkway, and the room should be lit sufficiently. For a more complicated boiler fitting or the relocation of a boiler, the heating engineer may need to remove old pipework and radiators, before installing the new boiler.

  2. New boiler installation

    Once the old boiler and any old pipework has been removed, the heating engineer will begin the installation of your new boiler and its pipework. Depending on how much work is required and how complex the job is, this part of the process can be extremely quick, especially if you're getting a like-for-like boiler.

  3. New boiler product tour

    Having fitted your new boiler and checked that it has been installed properly, the heating engineer will then provide you with a product tour. This covers how to use the controls, what features the boiler has, and how to set a schedule dictating when the boiler will be on or off. Be sure to take note of your new boiler's features and ask questions while you have the heating engineer present. This will help you to use your new heating system effectively and efficiently, and is a great chance to get answers from an expert.

Following boiler installation

After your boiler is installed, you should ensure the heating engineer provides you with a Building Regulations Compliance certificate which confirms the unit has been installed safely, and register the installation of your boiler with the manufacturer to validate the warranty. Most manufacturers request that this happens within 30 days of installation.

To keep your warranty valid you will have to get your boiler serviced annually by a Gas Safe registered engineer. This involves them inspecting the boiler inside and out, checking the flue pipe, ensuring that the gas pressure is correct and checking how the boiler performs during operation. Find out more about boiler warranties and boiler servicing.

What is needed for fitting a boiler?

Fitting a boiler is not something you should do for yourself. It can only be done safely and legally by a fully qualified professional, so the first thing you will need is a Gas Safe registered heating engineer (OFTEC for oil boilers). Sometimes this is all you will need to get a boiler fitted, as the heating engineer will often source the appropriate boiler and required components themselves. If you would prefer to source a boiler yourself to cut costs, it is possible to do so, but you will still need to have the boiler installed by a Gas Safe registered heating engineer.

Discover more in our article: What is the Gas Safe register?

Boiler installation regulations

When installing a boiler there are many building regulations that need to be followed. These include acceptable locations for the boiler to be situated, where the flue can and can't be located, whether the right size of gas pipe has been installed, and whether the boiler has a high enough efficiency rating. The list goes on.

Frankly, there are so many building regulations to follow when installing a boiler that it's best to let an accredited professional worry about them. So long as you get a Building Regulations Compliance certificate from the heating engineer, you'll know that all of the appropriate regulations have been followed.

The easiest way to ensure that your boiler installation follows all of the required building regulations is by using a Gas Safe registered heating engineer. We recommend getting comparison quotes from at least 3 heating engineers in your area, to ensure you get the best deal possible. You can do so by clicking the link below.

How long does it take to fit a boiler?

Depending on how complex the installation of a new boiler is, you can expect a boiler installation to take between 1 and 3 days to complete. The more complex the installation is, the longer it will take. Longer installations lead to more labour costs as well, which is something to consider if you're thinking about moving a boiler to a new location.
How long does it take to fit a boiler?

How quickly can you get a boiler installed?

For the most basic like-for-like boiler installation jobs, you can expect the installation to take between 4 and 6 hours to complete. However, you will need to agree a date with a local installer and it may take some time to find one, luckily, this is something we can help with.

Find an engineer to install your boiler

We have access to over 5000 heating engineers across the UK, we can put you in contact with local heating engineers within as little as 48 hours. All you need to do is click the link below and we'll get you free quotes from up to 3 Gas Safe registered heating engineers near you.


How much does a boiler installation cost?
The cost of installing a boiler can range vastly, depending on how complex the installation is. To get a rough idea of the costs, we recommend using our Boiler Installation Calculator

Can I legally install my own boiler?
Only if you are a Gas Safe registered heating engineer with the required accreditations. Otherwise you definitely should not do it yourself. Why You Shouldn't DIY!

Can a plumber install a boiler?
Only if they are a Gas Safe registered heating engineer as well as a plumber. Heating Engineers and Plumbers: What's the Difference?

Can you get a boiler installation comparison?
Yes and we highly recommend getting comparison quotes from up to 3 heating engineers near you. This is actually something we can help with: Get Free Comparison Quotes

How do I install a boiler in my house?
By enlisting the help of a Gas Safe registered heating engineer. How to Choose a Boiler Installer

Adam Cherry

About the author

Adam Cherry

Adam is our resident home heating expert. His experience and advice has helped millions of customers improve the efficiency of their homes and save money.

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