How much does a new boiler cost?

How much does a new boiler cost? This is such a broad question, it is hard to give a simple answer.


The answer to this question will depend on a number of factors;


  • What type of boiler
  • What size boiler
  • Is it a new installation
  • Is it a system conversion
  • Is there a complex flue system
  • What brand you choose
  • What warranty length you want

vaillant boiler

What are the different types of boilers?


The three types of boilers are


  • Combination boiler (combi)
  • Regular boiler (heat only)
  • System boilers

Combi boilers


A combination boiler, also known as a combi boiler. Tends to be more compact because it doesn’t need hot water cylinders. A single unit that generates all the heating and hot water for your home. Combi boilers heat water directly from the mains when you run a tap. No need for hot water cylinder or cold water tank in the loft.


  • Compact sizes make combis perfect for smaller properties
  • Ideal where there is little or no loft space
  • No need for a hot water cylinder allows increased living space
  • No cold water storage tank frees up a loft for conversion
  • No risk of loft pipework freezing
  • Less pipework in the home makes installation typically cheaper

Regular boilers


A Regular boiler(otherwise known as traditional, conventional or heat only). Comes with a hot water tank or cylinder where hot water is kept. Gallons of water can be heated, stored and readily used. The hot water cylinder will be fed via a cold water storage tank in the loft.


A regular boiler may be the best option on an older heating system. where the radiators and pipework may not like the added pressures that come with a system or combi boiler.


  • Perfect for homes where a lot of hot water is used at the same time
  • Ideal where there are two or more bathrooms
  • A good option in areas where water pressure is low
  • Compatible with solar water heating systems for a lower carbon footprint and lower energy costs

System boilers


A system boiler is like a conventional boiler, but more heating system components are built-in. They often take up less space as they don’t require a tank in the loft and therefore can be easier to install.


  • Ideal for homes with more than one bathroom
  • A constant supply of hot water to any number of taps at the same time
  • No need for a loft tank, freeing up space and eliminating worries about leaks or frost damage
  • Economical to run
  • Built-in components make installation quicker and neater


The size of the boiler you need will have an effect on the cost.

The bigger the heat output and the physical size will directly affect the cost of the unit

Here is a handy guide to be used as a rough guide to combi boiler sizing

A new installation, a system conversion or a relocation of the boiler will also affect the price

What is system conversion?

System conversion is where we convert from one type of heating system to another

For example, replacing an old back boiler unit and upgrading to a combi boiler.

This has more costs associated with it simply for the fact there are more materials and more labour involved.

Complex flue systems and other factors.

If your boiler is to be located on an internal wall and requires a vertical flue system. This can add significant costs to the job, especially if it is a long flue run. And you need a lead slate installing in the roof for the flue to terminate.

Condensate pipe installation

If your existing boiler is not a condensing boiler, or if your boiler is going in a new location. then the condensate pipework will need to be installed. Condensate pipework is there to carry the byproducts of combustion safely away to a drain. This can be via pipework or a pump if there are no drains nearby.

Gas pipe upgrades

Modern-day boilers are a lot more powerful than they used to be. This means that an older boiler may have been able to run sufficiently on a smaller gas supply pipe. Most boilers now require a minimum of 22mm pipework from the meter. And some of the bigger boilers such as the Worcester Bosch 50kw combi will require up to 35mm pipework.

Boiler Brands

The brand of boiler you choose will also impact the cost. Budget brands with less warranty are going to be cheaper than a more premium brand. A premium brand has a longer warranty, a better reputation and more reliable after-sales.

 how much does a new boiler cost?

As we have discussed it is not as clear cut as saying this is the price you will pay for a combi boiler, but here is a guide.

A budget combi boiler plus installation will cost from £1500

A mid-range combi boiler will cost from £1800

An upper range combi boiler will cost from £2000

And a top of the range combi boiler will cost from £2500

A system upgrade will be from an additional £700-1000

Relocation will be from an additional £700-1000

Upgrading the controls to a smart thermostat from £180

Every house and every installation will be different so these prices are just a guide and will need a thorough home survey.


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