Boiler Installation Guide

Boiler installation guide

Boiler installation and gas boiler fitting guide

This guide will ensure you get the best boiler installation possible and also what to look and ask for in a boiler installation quote if you require a replacement boiler.

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Boiler installation is really easy for an experienced Gas Safe boiler engineer from Boiler Central, as we install so many boiler installations across the UK every day (except Christmas day).

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What is boiler installation?

Boiler installation involves putting a new boiler in replacement of an old one as well as reconnecting the pipes, water inlet and a new boiler flue is installed. If you have any external water tanks, you may need these reconnecting or disconnecting. Installation time will take between 1 to 3 days dependent on the amount of work required.

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Does a Gas Safe registered installer have to fit the boiler?

gas safe

Yes, absolutely.

If you are having issues with your current boiler, getting a new boiler may be the best option. But when it comes to new boilers and the installation process, there’s a lot to learn.

The only people who should be installing a new boiler must be a Gas Safe registered heating engineer.

Gas Safe registered boiler installers are highly trained and have to prove they can install a boiler effectively and safely for your protection.

This guide on boiler installation will give you everything you need to know to order a boiler.

What are the different types of boilers you can have installed?

Did you know that different types of boilers can be installed so you can choose from various heating systems for your home?

The type you should choose depends on your individual needs and your home.

The three varieties of boilers that are fitted in the UK are:

  • Regular/heat only boiler installations
  • System boiler installations
  • Combi boiler installations

Different types of boiler installations in the UK

If you’re looking for a boiler replacement and new boilers, then you do have a range of options when replacing a boiler. Here is a list of potentially different types of installation that you can choose when you are changing your boiler.

  • New boiler installation – like for like swap
  • Boiler conversion – hanging from one boiler type to another
  • New boiler and relcocation – moving your boiler in the same room or another room
  • Boiler conversion with relocation – changing your boiler type and moving your boiler
  • Back boiler removal with conversion – you cannot replace a back boiler

As you can see you do have more than just the option of boiler replacement, you could move your boiler or change from a system boiler to a combi boiler if you think it would be more energy-efficient and better for your home.

Conversions and relocations are more expensive due to the time they take a Gas Safe registered engineer to complete.

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Regular boiler installation

A regular boiler—also known as a conventional, heat only, or traditional model—is standard with older residential properties.

With a regular boiler, you will have both a hot water cylinder and a separate cold storage tank.

If you have an older home, you may need to continue using this type as it is easier and less inconvenient to keep your existing install.

Installing a regular boiler in your home

If you already have a regular boiler and a hot and cold water tank then a new regular boiler can easily be installed to work with these. This type of installation will be quick and easy if just replacing your old one and will take the heating engineer around a day to complete.

If you require new hot water tanks or cold water tanks then expect the boiler installation to take longer. it may take up to two days to complete the full removal of the old boiler, the water tank, and fitting of the new tanks.

It’s crucial to note that these conventional appliances don’t do well with high water pressure, but they are great for distribution. This variety allows you to run hot water at once to more than one location if you live in a larger household.

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System boiler installation

Like the traditional type, the system model also requires a hot water cylinder. But with this variety, you’ll find that most of its critical components and features are part of the system itself.

For this reason, they are often easy to install. They also require less space due to the fact there is no cold-water tank. You still, however, need to have space for the hot water tank and ideally, you should already have a hot water tank if you are wanting a system boiler. If you don’t have a hot water tank you have a combi boiler or will need a combi boiler installing otherwise.

Installing a system boiler in your home

If you already have a system boiler then installing a new one will be the most cost-effective way and should take around a day to fit.

If you already have a hot water tank then a new system boiler will work with this also.

It can just be installed and plumbed into work as your old system boiler would have done. If you are requiring a new hot water tank then expect the fitting of the system boiler to take longer.

Full system boiler installation with a new hot water tank may take up to 2 days.

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Viessmann combi boiler

Combi boiler installation

The combi boiler, also known as a combination boiler, is popular because it combines a central heating boiler with a high-efficiency water heater.

These condensing combi boilers can be installed in most homes in the UK

The combination boiler comes in one compact unit which can be installed in kitchen cupboards if small enough.

A combi boiler draws directly from the mains water, so there is no need for a separate storage tank for hot or cold water.

Installing a combi boiler in your home

Installing a new combi boiler in your home is one of the most effective ways to save money on your utility bills. If you already have a combi boiler and want a new combi boiler installed in replacement of your old one, then expect this to take no longer than 1 day to fit.

If you have a system boiler and want to convert it to a combi boiler to remove your hot water tank, then this can take up to 2 days. System to combi boiler conversion installation is very popular in the UK right now.

Find out what the best combi boiler is here.

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How long does it take to install a gas boiler?

Installing or fitting a new boiler isn’t a quick job, it can’t be done in a few hours as installation needs to be done properly and safely.

Once a gas boiler is fitted, there are also safety checks to be completed by the installer. Take a look at our quick guide to see how long each different type of installation will take. If your installation choice is going to take a few days, we recommend that the best time to install a boiler is in the summer.

Combi boiler installation1 day
New combi boiler installation with relocation1-2 days
System to combi boiler conversion1-2 days
New system boiler installation1 day
System boiler installation with relocation1-2 days
New regular boiler installation1 day
Regular boiler installation with relocation1-2 days
Regular boiler to combi boiler conversion1-2 days
Back boiler to a combi boiler conversion2-3 days

How much is a boiler installation?

When customers want to install a new boiler system, one of the most common subjects they broach is the price. Specifically, how much do new boilers cost?

boiler installation prices

This question is crucial, and the answer is going to be different for everyone looking for new boiler deals.

For example, the price often depends on the brand. Worcester Bosch boilers may differ from Buderus and so on.

It also depends on which of the three varieties you choose.

For example, our customers frequently ask, “How much is a new gas boiler?”

Compared to other types of boilers, gas boilers are usually the most common type besides oil-based ones.

Other things that affect buying boilers new include what parts are needed, where you live, unit availability, and more.

At Boiler Central, we offer you quality boiler installation quotes and flexible monthly payment options when you need them.

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Boiler installation guide

Comparing boiler installs

When it comes to a new boiler and installation, you also want to compare units in the same category.

Have a look at some of the factors that you’ll need to consider and some additional perks that may come up in your research.

It isn’t likely that you will need all these extras when you install a new boiler system.

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Boiler fitting – How long does it take?

Boiler fitting takes different times to install due to such a varied workload required for each particular home type and also the type of boiler being fitted.

If you have a combi boiler installed and this is replacing an existing combi boiler, this should take 3-6 hours to fit. If you have a system boiler currently and would like to convert to a combi boiler.

This takes 1-2 days due to the installation requiring much more work to convert the system. A system boiler replaced with a new system boiler would be 3-6 hours.

Lastly, a back boiler to combi or system boiler would take 1-2 days on average for the boiler fitting

Next-day boiler installation in the UK

Next-day boiler installation is very common now in the UK You can easily choose your new boiler online and book an installation date with a Gas Safe registered engineer. All this can be done online and you get a fixed price installation quote.

Getting a next day boiler installation quote

You can get next-day boiler installation with Boiler Central if you order your boiler before 12 pm during the colder months, and 2 pm in the warmer months. This is great if you need an emergency boiler installation due to a broken boiler.

This is next-day fitting nationwide in England, Wales, and Scotland, so you do not have to be without heating for too long, even in the depths of winter.

Not many boiler companies can fit a boiler at such short notice nationwide so if you do require a boiler urgently, get a fixed quote online here in 20 seconds.

Gas boiler Installation energy regulations

The UK has passed several government guidelines for boiler installation and energy efficiency, which need to be adhered to for all boiler installations, so remember:

  • If you have a gas boiler, it must have at least a 92% ErP efficiency regardless of boiler type
  • A combi boiler installation requires one energy-saving feature
  • You must have functioning time and temperature controls

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Financing your gas boiler install


Getting a new boiler installed is an investment. You may not have the money on hand for the services you need so some people may turn to a credit broker or go directly to financial institutions to get connected with a loan.

At Boiler Central, we also provide various financial payment services from card to boiler finance.

For new boiler installation, you can pay by card, pay zero deposit, and pay monthly over 2 to 10-years.

Can a Gas Safe engineer install a hydrogen boiler?

With gas boilers being banned in 2025, boiler installation companies are only installing hydrogen-ready boilers. The best thing is that there is only a slight difference in these boilers so a suitably trained Gas Safe heating engineer can easily install a hydrogen ready boiler.

If there ever becomes a point where the gas network is changed to hydrogen in the future, then these types of boilers can easily be amended with a small amount of training from the engineer and a small part change on the boiler.

Nearly every boiler installed in the UK now is hydrogen ready, and if you have had a boiler fitted in the past year or so, it is likely that your boiler is already capable of running on a mix of hydrogen and natural gas. All the top manufacturers such as Worcester Bosch, Viessmann, Ideal, Baxi, and more only make H2 ready boilers.

Why choose Boiler Central for your boiler installation?

You can price up and buy a new boiler online

If you need a new boiler and installation, don’t hesitate to reach out to our award-winning Boiler Central team for more information. If you would like a new boiler quote then you can get everything, including installation from Boiler Central. We install nationwide with next-day installation if you order by 2 pm.

We know pretty much everything about boiler services and boiler installation, so feel free to ask if you have any questions. Call 0808 156 3888 or choose your fuel type below to get an online price in seconds:

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