New boiler cost in 2026
The short answer
- £1,800 to £3,500 installed for a like-for-like combi or system swap; median combi quote £2,300
- £3,000 to £5,700 to convert a regular or system boiler to a combi
- About £3,500 is the DESNZ average for a new gas boiler, or £2,950 to £4,050 by home size
A new gas boiler typically costs £1,800 to £3,500 installed for a like-for-like combi or system swap, and £3,000 to £5,700 if you convert a regular or system boiler to a combi. DESNZ puts the average at about £3,500 including VAT. Prices are typical, not quotes: the boiler, the controls and the work around it all move them.
New boiler cost by type
£1,800 to £3,500 for a like-for-like combi or system swap, £3,000 to £5,700 to convert to a combi.
| Job | Typical installed cost |
|---|---|
| Combi boiler, like-for-like swap | £1,800 to £3,500 |
| Combi boiler, premium model | £3,000 to £4,500 |
| System boiler, like-for-like swap | £1,800 to £3,500 |
| Regular (heat-only) boiler, like-for-like swap | £1,800 to £3,000 |
| Regular or system boiler converted to a combi | £3,000 to £5,700 |
| Back boiler replaced with a combi | £3,500 to £6,000 |
| Oil boiler replacement | £4,500 to £5,500 |
Read the detail
A like-for-like gas combi or system boiler swap typically costs £1,800 to £3,500 installed, and a regular (heat-only) boiler £1,800 to £3,000, in quotes the online installer Heatable gave across 2,000 jobs from January to June 2026. Its median quote for a standard combi swap was £2,300. Changing the type of system costs more: £3,000 to £5,700 to convert a regular or system boiler to a combi.
Typical installed prices from 2,000 Heatable quotes, January to June 2026 (updated 25 September 2026). Heatable sells and fits boilers itself, so these are one firm's prices, and a local installer can quote more or less. The figures are ranges because the boiler model, the warranty, the controls and the work around the boiler all move the price.
Two national averages sit above that median. The Department for Energy Security and Net Zero (DESNZ) puts a new gas boiler at about £3,500 including VAT, and the Energy Saving Trust gives £3,500 as the typical cost of replacing an old G-rated gas boiler with an A-rated one, with thermostatic radiator valves. The new boiler cost calculator puts both side by side for your home, and our guide to boiler prices by brand sets out the same installer's ranges for six makes.
By home size
About £2,950 for 1 bedroom to £4,050 for 5, scaling the DESNZ average of £3,500 for 3 bedrooms.
| Home | Average new gas boiler, installed |
|---|---|
| 1 bedroom | £2,950 |
| 2 bedrooms | £3,200 |
| 3 bedrooms | £3,500 |
| 4 bedrooms | £3,800 |
| 5 bedrooms or more | £4,050 |
Read the detail
A bigger home usually means a bigger job. Scaling the DESNZ average by home size, as all our calculators do, gives about £2,950 for a 1 bedroom home to £4,050 for 5 bedrooms.
The 3 bedroom figure is the DESNZ average of about £3,500 including VAT. Other sizes are scaled from it by our model, which is our assumption rather than a published figure. Our boiler vs heat pump calculator uses the same figures.
New boiler cost for your kind of home, with its gas use, saving and payback: 2 bed flat, 2 bed terrace, 3 bed semi, 4 bed detached house and bungalow.
What a new boiler price should include
The boiler, fitting, the flue, a magnetic filter, inhibitor, basic controls and the paperwork. Ask for each to be priced separately.
Read the detail
A full quote covers the boiler, fitting it, the flue, taking away the old boiler and the paperwork, which the installer must provide.
- The boiler and labour: removing the old boiler and fitting the new one in the same place, connected to the existing pipes.
- The flue: the pipe that takes the fumes out. A like-for-like swap usually reuses the same route; a new route, such as a vertical flue through the roof, costs more.
- A magnetic filter: the Energy Saving Trust says your plumber should fit one near the boiler if you do not already have one, because building regulations encourage it.
- Cleaning the system and inhibitor: the Trust says the chemical inhibitor that stops sludge and corrosion should be refreshed whenever an engineer drains the system, as happens in a boiler swap.
- Controls: the Trust's £3,500 figure includes thermostatic radiator valves; a programmer and room thermostat are the basics.
- Paperwork: the installer must be Gas Safe registered for a gas or LPG boiler, and must make sure the work meets building regulations and give you the documents to prove it. Keep them for when you sell.
Ask for each item to be priced separately, so two quotes can be compared line by line.
Extras and conversions
Conversions cost the most: £3,000 to £5,700 from a regular or system boiler to a combi. Moving the boiler and a power flush are priced after a survey.
Read the detail
Converting a regular or system boiler to a combi costs £3,000 to £5,700, and replacing an old back boiler with a combi £3,500 to £6,000, because both mean new pipework and taking out the tanks or the cylinder. A premium combi swap runs to £3,000 to £4,500.
Heatable lists the other jobs that push a price up: moving the boiler, removing a back boiler, a vertical flue, converting the system, a power flush or chemical flush, a new hot water cylinder, smart controls and upgrading the gas pipe. We found no published price for moving a boiler, a power flush or a new flue that we could check, so we do not give one: ask the installer to price each separately after a survey.
Before converting to a combi, think about the next boiler after this one. The Energy Saving Trust notes that most heat pumps work with a hot water cylinder, so taking the cylinder out now may mean putting one back if you switch to a heat pump later. Our combi vs system boiler guide covers which suits which home.
Oil and LPG boilers
£4,500 to £5,500 for an oil boiler replacement. We found no published LPG boiler price to give.
Read the detail
An oil boiler replacement typically costs £4,500 to £5,500 in Heatable's quotes. In Northern Ireland, where most homes use oil, the Energy Saving Trust puts replacing a G-rated oil boiler with an A-rated one at about £3,200.
We found no published price for an LPG boiler that we could check, so we give none. Off the gas grid, the Boiler Upgrade Scheme pays £9,000 towards an air source heat pump until March 2027 where the home has no mains gas, which changes the sums: see heat pump vs new boiler.
Grants for a new boiler
No general grant for a gas boiler. ECO4 can help households on qualifying benefits until 31 December 2026.
Read the detail
There is no general grant for a new gas boiler. ECO4 can help households on qualifying benefits replace or repair a boiler until it closes on 31 December 2026, and in Scotland Warmer Homes Scotland can fund a new gas boiler for eligible households. The Boiler Upgrade Scheme pays towards heat pumps and biomass boilers only. Our guide to boiler grants in 2026 sets out who qualifies for what.
Getting quotes
Three quotes from TrustMark certified, Gas Safe registered installers, compared item by item.
Read the detail
Get at least three quotes, as the Energy Saving Trust recommends, from installers certified by TrustMark, the government-endorsed quality scheme, and Gas Safe registered for gas or LPG. Compare them on the same boiler type and the same list of extras.
If the boiler still works, run the numbers first: our guide to whether it is worth replacing an old boiler gives the yearly saving and the payback by type of home. If it has broken and you have a repair quote, the boiler repair or replace calculator sets the quote against a replacement.
Frequently asked questions
How much does a new boiler cost in 2026?
A like-for-like gas combi or system boiler swap typically costs £1,800 to £3,500 installed, with a median quote of £2,300 for a standard combi at one online installer. DESNZ puts the average new gas boiler at about £3,500 including VAT.
How much does it cost to convert to a combi boiler?
About £3,000 to £5,700 to convert a regular or system boiler to a combi, and £3,500 to £6,000 to replace a back boiler with a combi, because of the new pipework and taking out the tanks or cylinder.
Is a combi boiler cheaper than a system boiler?
To fit, about the same for a like-for-like swap: £1,800 to £3,500 for a combi and £1,800 to £3,500 for a system boiler in the same quotes. The Energy Saving Trust says combis are often the least expensive kind. A system boiler suits homes that use more hot water.
Does a new boiler include a power flush?
Not always. Ask for it to be priced separately. The Energy Saving Trust says the inhibitor should be refreshed whenever the system is drained, and a magnetic filter fitted if there is none.
Can I get a free boiler?
Only through a scheme you qualify for: ECO4 for households on qualifying benefits until 31 December 2026, or Warmer Homes Scotland. There is no general free boiler grant. See our boiler grants guide.
Data sources
Heatable quotes, DESNZ and the Energy Saving Trust for prices, and GOV.UK for grants.
Show every source
- Heatable, New boiler installation costs 2026 (updated 25 September 2026): typical installed prices from 2,000 of its own quotes, January to June 2026. Heatable is an online boiler installer, so these are one firm's prices. Checked 5 October 2026.
- Department for Energy Security and Net Zero, Boiler Upgrade Scheme 2026 to 2030 summary business case, footnote 8: a new gas boiler costs about £3,500 including VAT. Other home sizes are scaled from it by our model, which is our assumption.
- Energy Saving Trust, Boiler types explained (last updated 20 May 2026): yearly savings for a gas heated home fitting an A-rated condensing boiler with a programmer, room thermostat and thermostatic radiator valves in place of an older boiler, by the old boiler's rating, at July 2026 fuel prices; £3,500 typical cost of replacing a G-rated gas boiler. Checked 5 October 2026.
- GOV.UK, Apply for the Boiler Upgrade Scheme: grants for air source and ground source heat pumps, biomass boilers and air-to-air heat pumps, checked 5 October 2026.