How Long Does It Take To Fit A New Boiler is reader-supported. When you buy through links on our site, we may earn an affiliate commission. Learn More

Are you thinking of replacing your boiler with a newer system? If you’re planning on a replacement or new boiler installation, you might have thought about the time it would take for this to take place. Are you wondering how long it takes to fit a new boiler? Then you’ve come to the right place.

The answer depends on factors like the nature of fitting, the location, the system, and upgrades included, and more. It should take anywhere between 5 hours to 3 days to install a new boiler.

How Long Does It Take To Replace A Boiler?

If it is a like-for-like swap, which refers to simply switching out the old boiler with a new model, it will take only a few hours. In such swaps, the new boiler has the same system and is fitted in the same location. This saves time in mapping new routes for cables and pipes, which you would need to do if while installing a new boiler in a different location.

If you change the system, say from a regular boiler to a combi boiler, that again would add around a day or two to your installation period.

The time needed to fit a new boiler in the same place would be anywhere between 4-6 hours. If you decide to change the location, it will take around 2-3 days to complete the installation.

If you’re upgrading from a regular system boiler to a combination boiler, then that would require you to set aside more time. This is because the regular system boilers have different pipe systems and setups. If your previous boiler had a cylinder system and the new upgraded system doesn’t, it would take time to set up differently.

The system boilers usually come with a cylinder pipework system, but there are heat-only boilers that require expansion and cold-water tanks, too. These boilers also need to be set up at higher locations, unlike the other ones.

You will also need to install newer and additional pipeworks. Along with this, make sure the location is ideal for the new system. There will be many changes to consider when you want to replace a boiler. Here’s the time it could take for the installation of various kinds of boiler systems:

Time Taken For Installation

The average time to replace a boiler that is a like-for-like swap would take anywhere between 4-8 hours. Since the model is the only thing changing and the location and the particular company you use isn’t, it should take considerably less time than system upgrades.

To replace a different system boiler with a newer or different system, it should take around 2-3 days for the complete installation. These days, you can switch the regular system boilers to combi boiler systems.

To replace a gas system boiler with a heat-only boiler, it will take you 2-3 days as well. But it could take an additional day if you didn’t set up the boiler at a high point. Heat-only boilers require to be set up at high locations as they doesn’t use mains pressure but gravity to run on.

If you’re planning on replacing your old boiler with a new one but in a different location, then that should also take you between 3-4 days. Sometimes it can even take more, depending upon the pipework and cable work required.

The installation of completely new boiler systems would take around 1-2 days, depending on the type of systems. Regular systems take quicker to be installed, while combi may take an additional day.

New Boiler, In A New Location

Are you shifting homes and want to install a brand new boiler in your fresh location? When installing a new boiler in a new location, the time required could be anywhere between 1-3 days. This is also true for installing a new boiler system in the same house but in a different location.

New installations are easier than replacements of outdated systems. But since it is a new place without any previous connections and pipework for a previous boiler, it could take a few days before you will be set.

If you had previously set up your place with a boiler system in a different location, but have moved the new one to another location, that again will cost you more time. The more distance between your old boiler location and the new one, the longer it could take.

The gas pipeworks will also need proper installation. The engineer should do all of it with the utmost care for safety. It is best to only hire engineers that are Gas-Safe Registered to keep your premises safe during installation.

Time Taken For Installation

Installation of a new boiler in a location, whether in the same house or a different one, should take around two days. It depends on the complexity of the water and gas pipework required for the setup.

Generally, it can take longer, for three days. But if the system is simple to set up and gas pipework is easy to install, it can even be done in 1 day.

How Long Does It Take To Install A New Combi Boiler?

If you already have a combi boiler and are replacing it with an updated model, then it should take you 4-6 hours. If there were no previous models of combi boilers installed in your place, then installing one from scratch can take longer.

A new combi boiler would take a day or two to be installed. If there hasn’t been a combi boiler system in place since before, then the set up of the pipeworks and tanks and location can take at least two days. Since a combi boiler comes with central heating systems, it would take a couple of weeks if there hasn’t been any in place before.

The actual boiler installation may only take two days, but fitting the heating system in your home will take longer. There will be radiators and heaters needing to be set up and placed efficiently, hence at least two weeks are required.

Many companies also offer both in-home and electronic survey options to gauge the cost and time it would take for installations. That differs from company to company and type of boiler systems. But on average, installations of boilers can take 1-4 days.

There are always factors that would need to be considered before determining an average amount of time.

Considerations When Determining Time Taken

Aside from the type of system and boiler being installed and its location, you must consider a few other factors to determine the time taken. These factors can alter the time it would take to install the systems from hours to days.

Depending on the location and the new pipework and positioning required, it could add extra hours to the process. Here are a couple of considerations when determining the time taken.

  • Power Flushing
  • Gas Mains Upgrade

Power Flushing – The system needs to be properly flushed out before you can move towards a new installation. The debris, dust, deposits, or other accumulations can easily be flushed out using achemical hot flush.

One thing to be cautious about when you are power flushing is the intensity of the power flush. Since most of them are pretty forceful and strong, it can lead to leaks in pipeworks, especially if it is an old system. There can also be an increase in pressure on the joints, pipeworks, and radiators.

Hot flushing takes considerably less time than power flushing. Powerflushing can take up to 8 hours or a day, while hot flushing can be done in a couple of hours.

Since power flushing is a cleansing process, it will improve the system’s efficiency and durability, so it is a must to be considered.

Gas Mains Upgrade – Older boilers have different gas pipe requirements than newer ones. If you are replacing an old one with a new model, then the gas pipework would need to be upgraded.

Older boilers may need around 15 mm pipe for gas supply, but updated models need at least a 22 mm one. The sizes can exceed 22 mm, too. The length of the gas run is also an important determinant, based on which you could even need a 38 mm pipe.

This can take anywhere between a day or a week. If the pipework needs to be upgraded and changed, which in most cases it does, it will take a few days for the setup. Otherwise, a few hours should be enough.

Related Posts

Last Updated on May 3, 2021

Frequently Asked Questions

Can I Fit A New Boiler Myself?

Only Gas-Safe registered engineers are allowed to install new boilers, so unless you are one, it is advised not to do it yourself.

Do You Need A Power Flush When Installing A New Boiler?

If your existing system is very old, it is better to power flush the system before installing a new one. This will improve efficiency and clean out any accumulated contaminants.

How Much Should It Cost To Replace A Boiler?

The cost will vary depending on the system and installation process, but a replacement can cost around £1,000-£3,000.

David Thompson

Author: David Thompson

Dave has been involved in the UK building sector for over 3 decades and has developed a particular interest in energy efficiency in the home.

Scroll to Top