10th May, 2022

How Long Does it Take to Fit a New Boiler?

When having a new boiler installed, one of the main concerns is how long this process will take. We detail this for you below.

How Long Does it Take to Fit a New Boiler?

A broken boiler can be incredibly inconvenient, especially in the winter months when it is cold and you’re left with no heating or hot water until an engineer can come out to replace it. If you're looking for a new boiler then please have a read of our best combi boiler guide.

For some unknown reason, boilers always seem to know when you’re at your busiest and decide to break at that exact moment, which is why we understand the pressure to get the job done as quickly as possible to get your heating up and running again without taking too much time out of your busy life.

Get a free fixed price quote for a new boiler installed fast!

Average time to fit a new boiler

On average, a new boiler installation takes between 1-3 days. This can vary if the boiler is being moved from one room to another, however if this is a simple boiler installation we would expect this to be completed within 1 day. Some installation companies will also require time to complete a survey, however at iHeat we conduct this survey via images you provide us with.

The time it takes to fit a new boiler can vary, depending on factors such as the type of boiler you currently have, if you’re swapping to a different type, if you wish to relocate your boiler and if any additional work needs to be done e.g. fitting all new pipes.

In this guide, we’ll take a look at how these factors can affect the time it takes to install a new boiler and the costs that come with it, but first let’s look at what a general boiler installation involves.

What Does a Boiler Installation Involve?

Arranging the installation

To arrange an installation with iHeat, simply answer a few questions about your home and then select the boiler of your choice from a range that we believe to be most suitable based on your answers.

You can then use our finance calculator to work out how you’ll be paying and choose a date for installation.

Once you have booked your installation, we will ask you to send us some images of your current boiler to send to the installer so they can prepare ahead.

We will also give you a call 1-2 working days before the install to confirm your order and the engineer that will be installing your boiler.

Removing the old boiler

When the installer arrives at your property between, they will display their Gas Safety Registered ID card to confirm their identity and will update you on their progress as they follow a checklist to ensure each task is completed to a high standard.

This begins with removing your old boiler.

Installing the new boiler

Once the old boiler has been removed, the engineer will start to install the new boiler in the same location, unless you have chosen to have it relocated, and a new iHeat thermostat. They will then fully test the new boiler and ensure the central heating system is fully balanced.

Disposing of old boiler and tidying up

The installer will tidy any mess and remove all packaging from your new boiler, as well as disposing the old boiler to ensure your home is left clean and tidy.

A few days after the install we will call to check how everything went and if we could have done anything better.

How Long Does it Take to Install a New Combi Boiler

4-6 Hours

Replacing an old combi boiler with a new combi boiler in the same location is the simplest and quickest job for an installer to do. Assuming everything goes smoothly, this will usually take an installer a day’s work (4-6 hours).

During this time, the engineer will remove the old boiler, install the new one and give it a free chemical flush (not to be confused with a ‘power flush’) and fit an iHeat thermostat.

Once the job is done, they will tidy and mess and dispose of the old boiler as well as the new boiler’s packaging.

Are you considering a new combi boiler? Get a free, fixed quote from £1,545 or £10.00 a month (9.9% APR) for 12 months.

How Long Does it Take to Replace a Regular/System Boiler with a New Combi Boiler?

Up to 2 Days

If you currently have a regular or system boiler and are looking to convert to a combi boiler, you should expect this to take longer than a like-for-like swap due to the extra work required, including removing the water tank that will no longer be required and any new pipework.

The installers must also gain access to the heating system which may mean that floorboards have to be lifted and any corrective work must be done afterwards.

Are you considering replacing your old system with a new combi boiler? Get a free, fixed quote from £2,200 or £14.23 a month (9.9% APR) for 12 months.

How Long Does it Take to Replace a Back Boiler with a New Combi Boiler

Up to 2 Days

If you currently have a back boiler and are looking to convert to a combi boiler, you should expect this to take up to two days due to all of the extra work required. First of all, you will need your boiler relocated to a different place in the house.

This could be inside a kitchen cupboard, in an airing cupboard, utility room etc…

Secondly, all boilers need a flue or some way to ventilate harmful gases such as carbon monoxide. Back boilers vent these gases directly up a chimney, whereas a combi boiler can vent in both horizontal and vertical directions.

This means that you’ll need a new regular flue from the new location of the boiler.

All of the work such as the removal of the back boiler, the relocation of the new combi and any repiping and flue work that must be done is why the price of a back boiler replacement is much higher than a like-for-like combi swap.

Are you considering replacing your back boiler with a new combi boiler? Get a free, fixed quote from £2,570 or £16.63 a month (9.9% APR) for 12 months.

How Long Does it Take to Relocate My Boiler?

+ Half a Day

There are a number of reasons why someone may wish to have their boiler moved from one position to another. For example, many homeowners feel that a boiler in their kitchen cupboard takes up too much space that could otherwise be used for storage.

In these cases, they may wish to have their boiler moved from their kitchen to the loft or an airing cupboard.

Due to the extra work involved in moving your boiler, such as repiping and installing a new flue, this can take around half a day on top of the time it costs to remove your old boiler and install the new one.

The further away from the original position you choose to move the boiler, the more complicated the job and therefore the longer it takes. The price of the job works in the same way.

Boiler Type


iHeat Cost

New Combi

Same Room


New Combi



New Combi



New Combi



New Combi

Utility Room


New Combi

Airing Cupboard


New Combi



Are you considering relocating your new boiler? Read our helpful blog about moving your boiler or check out our boiler relocation price guide.

Other Factors that Affect How Long it Takes to Install a New Boiler

Your Current Heating System Doesn't Meet Gas Safety Regulations

Unfortunately, in England and Wales there are over 60 deaths from carbon monoxide poisoning every year.

As a result, the government set up the Gas Safe Regulations which are there to prevent mistakes that could potentially result in a fatality.

One of the regulations that came into force within the last 15 years was the 22mm gas supply pipe rule. In the past, gas supply pipes had to be a minimum of 15mm, however this has since changed to 22mm.

Despite it being a legal requirement, many homeowners are unaware of this rule, so those who have boilers over 15 years old will likely have non-regulation pipes.

If an installer comes across 15mm pipes when installing the new boiler, they must legally replace your gas supply pipes with 22mm ones. This of course costs time and money, but it is a necessary part of the job.

Installing a Smart Thermostat

A smart thermostat has many benefits, such as giving you the ability to control your heating from anywhere and saving on your energy bills.

As standard, iHeat installs a free wireless controller, but we do offer the option of purchasing a smart thermostat which we can install and explain to you.

Whilst it doesn’t take too long, it does add on a small amount of time to your installation, as well as the added cost of the thermostat itself.

When the time comes to replace your old boiler with a new and more efficient model, you may have questions about what to do with your old boiler.

Whether you are concerned about the disposal of the boiler being environmentally friendly or if you’re simply just wanting to be rid of it without the stress of moving it yourself, with a boiler installation from iHeat, you don’t need to worry.

How to Dispose of Your Old Boiler

We don't recommend attempting to remove your own boiler. This is a job that should be done by a Gas Safe registered engineer due to the risks involved with gas boilers emitting harmful by-products such as carbon monoxide.

Unfortunately, in England and Wales there are over 60 deaths from carbon monoxide poisoning every year. As a result, the government set up the Gas Safe Register (formerly known as CORGI), which states that by law, all gas engineers must be registered as Gas Safe.

If anyone, even a trusted electrician or decorator, offers to mend or work on your boiler without being on the Gas Safe Register, they are breaking the law and could cause a potentially fatal accident.

iHeat Can Remove Your Old Boiler

When you get a new boiler installed by one of our Gas Safe registered engineers, they will remove and dispose of your old boiler, along with all of the packaging from the new boiler, leaving your home clutter-free.

Disposing of your new boiler

At iHeat, we take Gas Safety very seriously, ensuring all of our engineers are Gas Safe registered For your peace of mind, we make sure our installers display their Gas Safe card upon arrival so you can be sure the work will be done diligently and safely.

Ask a Gas Safe Registered Engineer

If you are having your boiler replaced by a Gas Safe engineer, they will remove your old boiler for you and what you then do with the boiler after this is up to you.

Usually, the engineer will be happy to take this away for you, but you could always attempt to take it to a scrapyard yourself to see what they will offer you in return.

Whilst it won’t likely be much, it could be an extra £40-£70 in your pocket, depending on whether you have any additional piping or tanks.

You can also rest easy knowing it will likely be recycled, meaning the disposal of your boiler is environmentally friendly.

If your old boiler is beyond economic repair and needs replacing, iHeat can install a brand new A-rated efficient boiler and remove and dispose of your old one at no extra cost. Get a free, fixed quote here.

Get a free, fixed quote on a new boiler with iHeat today.

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