How Much Does a New Boiler Cost?

For a straightforward replacement with no pipework changes, these are the typical 2026 UK installed prices:

  • Combi boiler: £1,800 to £4,000 installed. The most popular choice, heats water on demand with no tank.
  • System boiler: £3,000 to £4,500 installed. Works with a hot water cylinder, better for homes with two or more bathrooms.
  • Regular (conventional) boiler: £3,200 to £5,000 installed. Needs a cylinder plus a cold water tank, common in older homes.
  • Electric boiler: £2,500 to £4,500 installed. An option where there is no gas supply.
  • Oil boiler: £3,500 to £6,000 installed. For homes off the gas grid.

These are ranges from UK installer guides, as of 2026. Your quote can land anywhere inside them depending on your home, the brand, and how complex the job is.

What Affects the Price of a New Boiler

The boiler itself is only part of the bill. These are the factors that move the final number.

  • Boiler type. Combi boilers are the cheapest to install. System and regular boilers need extra components, which means more labour.
  • Like-for-like vs conversion. Swapping a combi for a combi in the same spot is the cheapest job. Changing boiler type can add £1,000 or more.
  • Moving the boiler. A new position means new pipework and a new flue. This alone can add several hundred pounds.
  • Property size. Bigger homes need higher-output boilers, which cost more to buy and to fit.
  • Brand and warranty. Premium brands with 10 to 12 year warranties cost more upfront than budget models with 5 year cover.
  • Extras. A power flush (£300 to £500), a smart thermostat (£150 to £300) and a magnetic filter are often quoted separately. Ask what is included.

How Long Does a Boiler Installation Take?

A like-for-like swap is usually finished in one day. Your heating is off for a matter of hours, not days.

Changing boiler type typically takes 2 to 3 days because of the extra pipework and controls. A full new system with a cylinder and new radiators can take the best part of a week. Your installer should give you a schedule before work starts.

How to Keep the Cost Down

  • Get three quotes. Prices vary widely between installers for the exact same boiler. Make sure every quote comes from a Gas Safe registered engineer.
  • Keep the same type and position. This is the single biggest saving. A straight swap avoids new pipework and flue costs entirely.
  • Book outside winter. Engineers are quieter in spring and summer, and some offer better rates out of peak season.
  • Ask what is included. Check whether the quote covers the power flush, filter, thermostat, controls and warranty registration, or whether those are extras.
  • Compare finance properly. 0% deals exist, but always compare the total amount payable, not just the monthly figure.

FAQ

How much does it cost to replace a combi boiler with another combi?

A like-for-like combi swap averages around £2,300 in the UK, within a typical range of £1,800 to £4,000 installed. It is the cheapest boiler job because no pipework changes are needed.

Can I get a new boiler on finance?

Yes. Many installers offer finance including 0% deals over 1 to 2 years. Always check the total amount payable and compare it against paying upfront, since longer terms add interest.

How long do boilers last?

Most modern boilers last 10 to 15 years with annual servicing. After that, parts get harder to find and efficiency drops, which is usually the point where replacement makes financial sense.

Is it worth replacing an old boiler that still works?

Often, yes. A modern A-rated boiler wastes far less gas than a 15-year-old model, so heating bills fall. Do the maths on your annual gas spend against the install cost before deciding.

Do I need a power flush with a new boiler?

Not always, but it is recommended if your system is old or sludged up. A flush (£300 to £500) cleans the radiators and pipework so your new boiler is not pumping dirt around from day one. Some warranties require it.

Who can legally install a boiler in the UK?

Only a Gas Safe registered engineer. It is a legal requirement for any gas boiler work. You can check an engineer on the Gas Safe Register before booking, and you should receive a certificate after the installation.