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How long does it take to fit a boiler?

Joe Minihane
Written by  Joe Minihane
5 min read
Updated: 10 Aug 2023

Depending on your home and the type of boiler you’re having fitted, installation can take anywhere from a few hours to three days. Read on and we’ll take a closer look so you know what to expect.

Should I invest in a new boiler?

Getting a new boiler fitted doesn’t have to be a stressful experience. If yours is over 15 years old, it may be inefficient, losing you money on your energy bills as well as lacking the environmental credentials of newer models.

The good news is that it doesn’t take long to fit a new boiler, with the timeframe ranging from one to three days depending on the kind of model you’re having fitted and whether it’s being put in a different part of the home compared with your old one.

Get it done in summer and you won’t have to worry about your house going cold while all the work is done, either.

Boiler installation

What does a boiler installation involve?

Boiler installation involves a few key stages, none of which need to be onerous. First of all, you need to choose which kind of boiler you want. You can either buy it independently and find an engineer to install it, or get one from a retailer that will send an engineer out when you buy a boiler from them.

When the engineer arrives, they will start by removing your old boiler. Once this has been completed, they’ll get to work on installing the new boiler. If this is in the same place as your old one, the process will be straightforward, but will take longer if it’s being relocated to another part of the property – or if you’re switching from an older style boiler to a new condensing (or combi) one.

As part of the installation, the engineer will fully check over the new boiler and ensure that it’s working properly before certifying it safe for use. And when it comes to disposing of the old boiler, they often also take it away, along with any mess created by its removal. This is a job which requires a Gas Safe engineer.

What affects how long it takes to install a boiler?

There are a number of factors which affect how long it takes to install a boiler. If you’re having a new combi boiler installed and it’s replacing an older combi, then the job is relatively straightforward and shouldn’t take more than a day.

However, if you’re getting rid of an older boiler with a large water tank, the job will take longer as you’ll need to have more parts removed and need some new pipework fitted.

Having a boiler fitted in a new part of the home will also take longer, as you’ll need to have new pipework to connect the heating to the boiler in its new location. This may involve lifting up floorboards and other disruptive work.

What is the average time for a new boiler to be installed?

The average time for a new boiler installed depends on the kind of work you require.

Expect a new combi boiler installation to take up to one day, while replacing an older regular boiler with a new combi boiler can take around two days.

Moving your boiler to a new part of the home can take an extra half day. Additional issues, such as the need for 22mm wide pipes when replacing very old models, mean work may go on for as many as three days.

Are combi boilers quicker to install?

In general, yes. Combi boilers are smaller and a lot more common than other types of boilers, meaning engineers should be able to install them within a day as long as the old model can be easily replaced.

If you’re having it placed in a new part of the home or getting rid of a very old system, however, then it may take longer.

How long does it take to move an existing boiler elsewhere in the home?

Moving your existing boiler to a new part of the home can take anything between half a day and one day.

A lot depends on where you want to move the boiler and how far away it is from its previous location. This is because an engineer will need to fit new pipework and a new flue. They’ll then need to run the requisite safety check to ensure it’s all working properly.

What to expect when you have a new boiler installed

When you have a new boiler installed, the process should follow similar steps, no matter what kind of job you’re having done.

A Gas Safe engineer should show you their credentials before they enter your home.

They will then ask to have the water switched off, before removing the old boiler and checking that all the pipework is ok, then start on the installation of the new one.

Once the new boiler has been fitted, they will then turn the water back on and fill the boiler, making sure that the pressure is correct and the boiler properly balanced. They’ll then check that the heating is working and that you can get hot water.

Gas Safe engineers are also registered to dispose of your old boiler, meaning they should take away any parts and clear any mess before they leave. Just be aware that you may need to sign up and pay for this as an additional service when you book your boiler installation.

If you are having a boiler relocated, engineers may need to move floorboards and fit new pipework, which may mean you are without heating and hot water for a few days. Be sure to check all details prior to installation.