A new boiler in the UK costs between £1,800 and £4,500 fully installed for most homes, with prices checked in October 2026. A straightforward combi swap, where the new boiler goes in the same spot as the old one, often lands between £1,900 and £2,800. Bigger homes, system boilers and conversions cost more. The Energy Saving Trust puts a typical A-rated replacement, fitted with new radiator valves, at around £3,700. Here is what homes like yours actually pay, and what moves the price up or down.
Photo: Kai Kemmann, CC BY-SA 4.0
New boiler cost by type
The type of boiler is the biggest single factor in the price. Combi boilers are the cheapest to buy and fit because they heat water on demand and need no cylinder or tank. System and regular boilers cost more because they work with a separate hot water cylinder, and regular boilers also keep a cold water tank, usually in the loft. The table below shows supply only prices for the unit itself, plus typical fitted prices for a like-for-like replacement.
| Boiler type | Unit only | Typical installed cost |
|---|---|---|
| Combi | £600 to £2,500 | £1,800 to £3,500 |
| System | £800 to £2,850 | £2,500 to £4,500 |
| Regular (heat only) | £450 to £1,750 | £2,500 to £4,000 |
Checkatrade figures quoted by Uswitch allow a wider spread, up to £6,000 for a combi, which covers large premium models and difficult jobs. At the other end, online fixed price installers advertise combi boilers from around £1,790 fitted. Most households end up somewhere in the middle.
What a new boiler costs by house size
House size decides how powerful the boiler needs to be, measured in kilowatts (kW). More bedrooms and bathrooms mean a bigger boiler, more pipework and longer on site. These are typical fitted prices for a like-for-like swap in the same position.
| Home | Usual boiler | Typical installed cost |
|---|---|---|
| 1 to 2 bed flat | Combi, 24 to 28 kW | £1,800 to £2,800 |
| 3 bed semi | Combi, 28 to 35 kW | £2,300 to £4,000 |
| 4 to 5 bed detached | System, 25 to 35 kW | £3,500 to £7,000 |
London and the South East sit at the top of these ranges. Labour there can run 10 to 25 percent higher than in the Midlands or the North, and a large detached home in London is the most expensive combination of all.
What is included in the installation price
A proper quote covers more than the box on the wall. Standard fixed price installations from the big online installers normally include:
- The new boiler and its flue kit
- Removal and recycling of your old boiler
- Standard pipework, fittings and making good
- A chemical flush to clean the system before start up
- A magnetic filter to protect the new boiler
- Basic heating controls, such as a programmable thermostat
- Commissioning, Gas Safe paperwork and warranty registration
One thing that is often not included is a full powerflush. Many quotes include the gentler chemical flush instead, so check which one you are actually getting before you compare prices.
Extras that push the price up
These are the add-ons that most often explain why one quote comes in hundreds of pounds higher than another for the same boiler.
| Extra | Typical extra cost |
|---|---|
| Moving the boiler to a different room | £400 to £1,200 |
| Converting from a regular or system boiler to a combi | Adds £800 to £2,000 |
| Full powerflush of an old, dirty system | £300 to £500 |
| Magnetic filter, if not already included | £100 to £200 |
| Smart thermostat (Hive, Nest or Tado), supplied and fitted | £175 to £300 |
How long does a boiler installation take
A like-for-like swap is usually done in a single day. BOXT lists one day for a straight swap of the same boiler type, British Gas allows one to two days for a combi installation, and HomeServe puts a straightforward swap at around six to eight hours. Changing boiler type, for example from a regular boiler with tanks to a combi, takes about two days, and up to three if the pipework needs a lot of changes. Moving the boiler to a new room adds roughly half a day.
What a boiler service costs afterwards
Budget for an annual service once the boiler is in. A one off service for a gas boiler costs £80 to £120, with an average of around £100 according to Checkatrade, and it takes 30 to 60 minutes. Which? puts the typical range slightly lower, at £70 to £110. The service is not only about safety: most manufacturers keep the warranty valid only if the boiler is serviced every year.
Can you get a grant for a new gas boiler
For most households, no. The Boiler Upgrade Scheme, the main heating grant in England and Wales, pays £7,500 towards a heat pump and £5,000 towards a biomass boiler in rural off-gas areas, but it cannot be used for a new gas boiler. The one real exception is ECO4. Under ECO4, households on qualifying benefits, or with a household income under £31,000 through a local authority referral, can get a free replacement boiler if the home has an EPC rating of D to G and the old boiler is inefficient or broken. ECO4 covers Great Britain and is due to close on 31 December 2026, so check your eligibility before you pay for anything.
How to cut the cost of a new boiler
- Get at least three fixed, itemised quotes, including one from an online fixed price installer and one from a local Gas Safe engineer.
- Keep the boiler in the same place. A like-for-like swap is the cheapest job there is.
- Keep a hot water cylinder that still works. Replacing a sound cylinder adds hundreds of pounds for no real benefit.
- Look at mid range brands as well as the famous names. Units from ranges such as Ideal Logic often cost several hundred pounds less than premium models, and still carry long warranties.
- Book in summer if the old boiler can wait. Engineers are quieter outside the winter rush and keener on price.
- Check ECO4 first. If you qualify, the replacement could be free.
New boiler cost FAQs
How much does a new boiler cost?
For most UK homes, between £1,800 and £4,500 fully installed. A simple combi swap is usually £1,900 to £2,800, while large detached homes with a system boiler can pay £3,500 to £7,000.
How much does a new boiler cost with installation?
The prices in this guide already include installation. Bought on its own, the boiler unit costs £600 to £2,500 depending on type and brand. Fitting commonly comes to around £1,500 on average according to Checkatrade's cost calculator, which is why the installed total is so much higher than the unit price.
How long does it take to fit a new boiler?
One day for a like-for-like swap. Allow two to three days if you are changing boiler type or moving the boiler to a different room.
Is a combi boiler cheaper than a system boiler?
Yes, in most cases. A combi needs no cylinder or tank, so it is cheaper to buy and quicker to fit. Heatable's starting prices show the gap: combi boilers from £1,975 fitted, system boilers from £2,445 fitted.
Can I get a grant for a new gas boiler?
There is no general grant for a gas boiler. The Boiler Upgrade Scheme only funds heat pumps and some biomass boilers. Low income households may qualify for a free boiler under ECO4, which runs until the end of 2026.
If your quotes are landing well above these ranges, it is worth asking whether a boiler is the right buy at all. Our guide to heat pump costs in the US, UK and Germany shows what the low carbon alternative costs in 2026, and our 10 year comparison of a new boiler versus a heat pump works out which one is cheaper over time. Staying with gas? Our ranking of the cheapest way to heat a home will help you keep the running costs down.
Sources and further reading
- Uswitch: New boiler and installation costs (Checkatrade price data by boiler type)
- Heatable: New boiler installation costs 2026, prices by type
- Hometree: New boiler vs boiler repair (total typical range £1,500 to £4,500)
- Checkatrade: Boiler service cost in the UK, 2026 prices
- GOV.UK: Apply for the Boiler Upgrade Scheme