Updated: April 21, 2024

To begin with, the cost of a new boiler mostly depends on the installation requirement and the type of home you live in. In addition to any add-ons.

We will look into the cost of different kinds of boilers as well as the cost of replacing you boiler with another system.

Whether you want to know the cost of a combi, a system or a regular boiler, we’re here to help.

How much does a new boiler cost?

Here’s a table of the average prices for boilers:

New boiler install£2,899
Combi to combi swap£1,795
System to system£1,999
System to combi conversion£2,499
Back boiler to a combi£3,299
Megaflo unvented boiler£2,499

All in all, combi boilers sell for £1,500 to £2,750.  While system boilers can sell for £1,600 – £2,900 and regular or heat only boilers go for for £1800 – £3,200.

How much does a standalone boiler cost?

All things considered, it is hard to pinpoint exactly how much a standalone boiler costs. But the range starts from £600 to £2,500.

Read more: Vented Hot Water Cylinders

How much does a new combi boiler cost?

A combi boiler can cost between £1,500 and £3,000 depending on the model in question. This price includes the following:

  • Firstly, the price of the new combi boiler itself.
  • Secondly, installation cost
  • Lastly, warranty registration

This is the cost you can expect to pay. It also includes VAT.

The labour cost can vary, without a doubt, if you want to replace:

  • An existing combi boiler with a combi boiler
  • A system boiler with a combi boiler
  • A regular (heat only) or a back boiler with a combi boiler

Other factors which might influence the price for combi boilers:

  • The complexity around your boiler flue
  • Amount of new pipework
  • Moving your boiler
  • What floor your boiler is on (scaffolds might be needed in flats)
  • Location inside the UK (London has higher prices)
  • Warranty length

As can be seen, many things can affect the price and cost of a combi boiler. However, replacing a combi boiler with another combi is a straightforward job.

A mid-range combi boiler will probably cost you around £1,800 with a long 10-year warranty. In this case, the Worcester Bosch 2000 boiler is a good example for such a cost.

Without a doubt, the cost will increase if you’re replacing your current boiler system with another one.

Read about: Best combi boilers & boiler brands

System to combi boiler cost

Replacing a system boiler with a combi boiler ranges from £2,300 – £3,000.

A combi boiler takes less space than a system boiler. As a result, you will have more space in your home after you get a combi boiler.

Replacing a system boiler with a combi boiler is a big job and includes additional work. It might take the installation team 2-3 days to finish the work to be sure.

A system to combi boiler conversion costs around £2,300 for a basic to a mid-range boiler. And for a higher-end boiler the price would be around £3,000 on the whole.

Read about: The Best Brands of System Boilers & Pricing

A System boiler replacement cost (swap)

Replcing your system boiler with another system boiler will cost you between £1,600 to £2,900.

In this case, you would only replace the boiler and not the water tank.

For a basic boiler with a five-year warranty, the cost would be around £1,600.

A mid to high-end system boiler replacement might cost you £1,900 to £2,900 depending on the model and manufacturer.

Read more: Combi boilers common faults  

Regular boiler replacement cost and prices

Firstly, a regular boiler replacement can cost around £1,900 to £2,200.

The price does not cover a new hot or cold water tank. You do not need to pay for a new water tank because, in most cases, they last for long.

For one thing, a budget boiler with a low warranty could start at £1,900. Whereas a mid to high-end heat only boiler with a good length warranty might cost £2,200.

Read about: Boilers On Finance

Regular conversion to combi boiler cost and prices

Converting you regular boiler to a combi boiler would probably cost £2,300 – £2,500.

Your water tank will be removed since there is no need for it any longer.

And sometimes the cold water tank will be left in its place due to the difficulties of removing it.

You would pay £2,300 for a basic boiler, with a low warranty. For a mid-range boiler and some higher-end boilers you might pay £2,500.

Back boiler replacement costs and prices

To begin with, you can’t replace a back boiler with another one because of some regulations.

It’s ok to use an existing back boiler but you can’t install a new one.

They are expensive to run, unreliable and dirty.

Most people usually replace their back boilers with combi boilers.

Back boiler to combi boiler costs

For a budget combi boiler with a low warranty you would pay £3,100 to £3,200. And for a mid to high range combi boiler you could pay £3,500.

You will need a boiler flue, a waste condensate pipe. Thus, the additional cost.

This kind of investment is certainly worth it. Moreover, a combi boiler would increase the value of your home.

Read more: Common Sime Boiler Error Codes

The average cost of a new boiler

Here’s a table of the average cost of a new boiler installed and fully working:

Type of boilerAverage cost
regular (heat only) boiler£2,100
Average system boiler£1,950
Average combi boiler£1,800
Average Megaflo£1,900

Gas boiler costs

The price for a mid-range, gas combi boiler will be around £1,800. While a mid-range gas system boiler might be around £1,950. Lastly, a regular (heat only) gas boiler will be around £2,100 on average.

Of course, the prices we just mentioned include the cost of installation and any other additional work needed.

Read more: Top UK System Boilers

Regular Boilers and how does it works

How long would a boiler last?

A new boiler should at least last for 10 years. But the expected lifespan for a boiler is from 10 to 15 years working at high efficiency.

Boiler relocation costs

Relocating your boiler can cost more money. It will involve several new fittings and fixtures, as well as extra pipework, and a lot of physical labour.

We advise you to avoid relocating your boiler unless you have to. You might need to relocate your boiler if you’re replacing a back boiler with a combi, a system or a regular boiler.

Moving your boiler from the kitchen to the next room might cost you £200. However, moving your boiler from the kitchen to the loft might cost around £400 to £600.

Read about: New Boiler Quote

New heating controls and smart thermostat cost

Presently, you can turn off and on your boiler easily using a controller or your smartphone.

The average price for a controller is between £30 and £300.

In short, smart thermostats cost between £100 to £300 depending on the model.

Plume Kit Cost

To begin with, a plume kit is an extension kit attached to the flue of the boiler. You will need one if your boiler is too close to your neighbour.

The average cost of a plume kit for your new combi, regular or system boiler ranges from £75 to £150.

Chemical flush cost

A Chemical flush might cost you £50 to £150.

On the positive side, they help you get rid of sludge from your heating system. If not cleared, sludge can block the hot water from flowing efficiently around your radiators.

You will need a deep clean if your radiators are cold at the bottom. The most common way to do this is by using a hot, chemical flush.

But you must be careful. Flushes can do more damage than good. Not to mention that a lot of damage can be caused by forcing high-pressure water through a heating system.

Boiler flue cost

To clarify, a boiler flue is a big piece of pipe which leads from the boiler to the outside.

The flue ensures that the flue gases and condensation are pumped outside and not into your face.

Of course, flues leaving your home horizontally adds no extra expenses.

On the other hand, flues leaving your home vertically through your roof require more work and as a result more expenses.

The typical cost for a flue is between £500 to £20, depending on the length needed and type.

To sum up, a vertical flue is more expensive than a horizontal flue.

Magnetic boiler filter cost

The cost for a magnetic boiler filter ranges from £100 to £200.

Firstly, filters protect your boiler. They are installed inline on the pipework. They trap small particles of dirt and metal, stopping them from going into the boiler and causing unnecessary damage and leaks.

Read more: Best Ground Source Heat Pumps and Prices

New Boiler Cost

Prices for different boiler brands

Combi boilers

  • Baxi £880 – £1,000
  • Glow Worm £700 – £990
  • Ideal £590 – £1,270
  • Potterton £650 – £1,350
  • Vaillant £1,160 – £1,410
  • Viessmann £780 – £1,280
  • Worcester Bosch £800 – £2,460

Heat only boilers

  • WORCESTER-BOSCH GREENSTAR UTILITY 50 – 70 (OIL)– £1,700 – £1,900
  • GREENSTAR FS 42CDI REGULAR – £1,500-£1700
  • WB GREENSTAR 30CDI REGULAR -£1,200-£1,300
  • VAILLANT ECOTEC PLUS 428 – £800 – £900
  • ECOTEC PLUS 415– £600-£800

Can I get the next-day boiler installation?

Of course you can if you order your boiler before 12 pm during the colder months, and 2 pm in the warmer months.

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

Not many boiler companies can fit a boiler at such short notice nationwide. If you need a boiler, get a quote from us as soon as possible.

Read more: Electric Boilers v Gas Boilers

Top UK Heat Only Boilers


What is the average cost of a new gas boiler?

combi boilers sell for £1,500 to £2,750.  While system boilers can sell for £1,600 – £2,900 and regular or heat only boilers go for for £1800 – £3,200.

How often should you change your boiler?

he average boiler lasts around 15 years if well maintained and although a yearly service can improve the lifespan, an older boiler has to work harder to heat your home.

How much does boiler installation cost?

The most affordable boiler for most UK households is a new combi boiler, costing £500 – £3,000; or a conventional boiler