Boiler Installation Cost Calculator UK – New Gas Boiler Costs

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How much does a new boiler cost? What factors impact the price of a new boiler quote?

At present, the average cost of a combined new boiler and installation package is in the range of £1,600 – £2,500 for a combi boiler, £1,700 – £2,000 for a regular boiler and £1,900 – £2,200 for system boilers.

In this guide, we will take you through some of the most common boiler replacement scenarios. All prices will assume you are opting for mid-range models and include labour and VAT.

If you would like a quote tailored to your exact requirements, feel free to use our quick and easy boiler quote form to get an instant quote.

Boiler Installation Calculator

We’ve created this calculator tool to provide you with the estimated costs of a new boiler, plus gas safe installation. The results provided will offer a range of boilers suitable for a variety of different budgets.

The boiler installation calculator asks a series of questions to get an idea of your exact requirements, these include the following:

  • Type of property.
  • The number of bedrooms.
  • The number of radiators.
  • The number of bathrooms.
  • Type of boiler required e.g. combi, system, or regular.
  • Whether you want to move your boiler to a different location.

Please note that the prices are estimations, but it’s a useful tool if you are simply looking for a rough estimate of boiler costs.

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Boiler Installation Cost Examples

Here we will take you through some of the most common installation scenarios based on the boiler type e.g. combi, regular and system and include labour costs and VAT.

Combi Boiler Installation Cost

Combi boilers are the most widely used type of boiler in the UK. They provide hot water and heating from a single unit, so can be easily stored in homes with limited space.

The two most common combi boiler installation scenarios are as follows:

  • You are replacing an existing combi boiler.
  • You are converting from a regular boiler and cylinder to a combi boiler.

Replacing an Existing Combi Boiler

If you are simply replacing an old combi boiler with a new one within the same location, then this will cost around £2,000 and take 1 day on average.

What if You Want to Move the Location of Your Boiler?

If you are replacing an old combi boiler with a new one but want to move its location, then on average you can expect to pay around £2,500 and the work to take 1 and a half days to complete.

Converting from a Regular to a Combi Boiler

It is relatively common for people to change or convert their boiler type, often they convert from a regular boiler (including storage cylinder) to a combi boiler. On average the cost of this is £2,700 and you can expect the installation process to take around 2.5 days.

Regular Boiler Installation Cost

Regular boilers or conventional boilers come with a boiler that provides heat and a separate cylinder that provides hot water to your home.
The two most common regular boiler installation scenarios are as follows:

  • You are replacing a regular boiler in the same location with the same type of boiler.
  • You are replacing a regular boiler with a new regular boiler in a different location.

Replacing an Existing Regular Boiler

If you just want a straightforward swap from old to new in the same location, then you are looking to pay around £1,800, which would take around 1 day to complete.

What if you want to Move your Regular Boiler to a New Location?

The exact price of moving your regular boiler will depend on where, as it is largely down to the amount of new pipework that needs to be fitted. For example, moving your regular boiler within the same room is going to be cheaper than moving it from a ground floor room to the attic.

With that said, for a standard move within the same room and without moving the storage cylinder you can expect to pay a £600 moving fee. So that would be £2400 in total including the boiler, installation and the cost of the boiler move. On average, this would take around a day and a half to complete.

System Boiler Installation Cost

System boilers work in tandem with an unvented hot water tank to provide hot water. Typically, they are installed in properties with multiple hot water outlets e.g. homes with multiple bathrooms.

The most common system boiler installation scenarios are as follows:

  • You are replacing a system boiler within the same location.
  • You are replacing a system boiler and vented tank with a new system boiler and unvented tank.
  • You are replacing a combi boiler with a heat-only boiler/unvented cylinder.

Replacing an Existing System Boiler

If you are looking to replace an existing system boiler with a new model within the same location, then this will cost around £1,900 and take 1 day on average.

Replacing a System Boiler & Tank

If you are wanting to upgrade both your system boiler and storage tank with a brand-new boiler and unvented cylinder, this will cost you on average £4,000 and take around 2 and a half days to complete.

Replacing a Combi Boiler with a System Boiler

Combi boilers are the most popular type of boilers in the UK, but for some homes, they are not adequate and fail to provide enough hot water, particularly in larger properties with more than one bathroom.

That is why many people choose to convert their combi boilers to a system boiler instead. If this sounds like you, you will require a brand-new cylinder and system boiler, which will cost £4,500 on average and take around 2 and a half days to complete.

Back Boiler Replacement Cost

Back boilers are a very outdated type of boiler, commonly installed behind the fireplace. When they need to be replaced, people typically opt to replace them with either a combi or regular boiler.

Here are the most common back boiler scenarios:

  • You replace the back boiler with a brand-new regular boiler and keep the water tank.
  • You replace the back boiler and hot water tank with a new combi boiler.

Replacing a Back Boiler with a Regular Boiler

Should you decide to replace your back boiler with a modern regular boiler and retain your current hot water tank, you can expect to pay around £2,500 and the work will take 2 days on average.

Replacing a Back Boiler with a Combi Boiler

If you are wanting to replace your back boiler and tank with a brand-new combi boiler, this will cost you on average £3,500 and take around 2 and a half days to complete.

Why Do Boiler Prices Vary So Much?

There are a variety of factors that influence the price of a boiler installation quote, as a result, the prices vary too, here are some of the major ones:

Type of Boiler

The type of boiler you require had an impact on price since some are inherently more expensive (on average) than others. For example, a mid-range combi boiler is typically cheaper than a mid-range system boiler installation.

Why? Simply because a system boiler is larger and therefore more materials are required in the construction. They are also larger and consist of both a boiler and a separate storage tank, so require more time to install.

Moving your Boiler

If you need to move your boiler from one location to another, it requires more labour, such as lifting floors and drilling through walls to install new pipework and so you can expect to pay more for the engineer’s time.

The additional pipework that needs to be installed is also made from copper, which is by no means a cheap material, so this is also an additional cost to consider.

Hot Water Demand

The type of property you live in can also play a major role in the boiler quote you receive. For example, if you live in a large home, with dozens of radiators and multiple bathrooms, your hot water demands are going to be greater than a small two-bedroom terrace with a single bathroom.

This hot-water demand determines not only the type of boiler that is suitable for your property but also the size of the boiler you require. For example, a combi boiler is not going to be suitable for properties with multiple bathrooms, instead, a regular boiler or system boiler is more suitable, which cost slightly more on average.

Additionally, the average UK household has a bath and a shower, in which case a 24-30 kW boiler will usually be advised. Yet in homes with additional outlets e.g. an extra bathroom, a larger boiler of 30-35 kW boiler may be recommended, further increasing the cost.

The Installer You Choose

Another major factor in boiler installation cost is the installer you choose and believe it or not this alone can increase the price by as much as 50%.


Larger boiler installers such as British Gas have huge overheads to pay for, including office staff, installers, and customer service centres and so they naturally factor this into their pricing structures. Passing these costs onto you, the consumer.

Sole traders with a single van are often cheaper than large suppliers as they do not have huge overheads to pay for, but their downfall is that you can never rely on them to return for repairs. Once the installs are complete, there is no guarantee you will hear from them again.

Online companies such as Heatable can offer much more competitive pricing since we have a dedicated network of engineers throughout the country. We can also get great deals from boiler suppliers since we buy in bulk and so can pass these savings onto our customers.

Our contracts are also with the customer and since we care about maintaining a 5-star reputation, we always endeavour to do whatever it takes to make sure all our customers are 100% happy. That means offering a fixed price, a price match guarantee, and installation as fast as 24 hours.

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Do You Require Any Extras?

If you opt for additional services and products, then these will also involve an additional cost on top of the standard boiler installation.
Many great extras can have a huge impact on the longevity and long-term performance of your boiler and overall heating system, so they are certainly worth considering.

These commonly include the following:

Power Flush

The quality of your heating system’s water is often overlooked, but it is fundamental for the performance and longevity of your heating system.

If your water is dirty and is rarely cleaned, then over time, the content of that water is going to cause damage to your boiler and heating system.

For instance, sludge and rust can build up over time, resulting in cold spots and worse still these residues are a leading cause of damage to metallic components.

A Power Flush is essentially an effective method of cleaning your heating system’s water using a combination of high pressure and cleaning chemicals. It is highly recommended to do this periodically, but especially before installing a new boiler.

It is an additional cost, but it is worth the investment, so you can be more confident dirty water is not left to damage your brand-new boiler.

A Magnetic Filter

A relatively new innovation to the boiler market is magnetic filters, such as the popular Adey Pro Filter. These clever pieces of kit are connected to your heating system and using magnetic technology work to collect metallic debris before they cause damage to your system.

Even better, some filters are now able to monitor the quality of the water over time, giving you and your engineer useful data, allowing them to be proactive rather than reactive.

Smart Thermostats

A smart thermostat, such as the Hive Smart Thermostat synchronises with your boiler, giving you the ability to monitor your home’s heating remotely and access a range of other useful features.

For example, you can set daily schedules, allowing you to set up different temperatures and hot water “slots” throughout the day. It will also notify you if you have left your heating on and helps protect your pipes from freezing during winter using the “Frost Protection” feature.

Boiler Installation Cost Calculator Final Words

Boiler installation costs can vary dramatically based on the size of your home, hot water demands, boiler type, the installer you choose, and whether or not you plan on converting to a different type of boiler or want to move it to another location within your home.

Ultimately, this information is required for you to get an accurate quote. Thankfully, we have developed a quick and easy boiler installation quote form, which takes all these factors into account and presents you with a set of results almost immediately.

If you would like a quote tailored to your exact requirements, feel free to use our quick and easy boiler quote form to get an instant quote.

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