How much does a new boiler cost in the UK (2026)?
A like-for-like combi boiler swap usually costs £1,800 to £3,500 fitted in 2026, according to Heatable, while Checkatrade puts the average supply-and-fit price of a gas boiler at around £3,000. Converting from a regular or system boiler to a combi costs more, typically £3,000 to £5,700 (Heatable).
How much does each type of boiler cost to replace?
| Job | Typical fitted cost | Source |
|---|---|---|
| Like-for-like combi swap | £1,800 to £3,500 | [1] |
| Premium combi swap | £3,000 to £4,500 | [1] |
| Gas boiler, supply and fit (average) | around £3,000 | [2] |
| System boiler replacement | £1,800 to £3,500 | [1] |
| Conventional (regular) boiler replacement | £1,800 to £3,000 | [1] |
| Regular or system to combi conversion | £3,000 to £5,700 | [1] |
| Regular to combi conversion | around £4,000 | [2] |
| Back boiler to combi conversion | £3,500 to £6,000 | [1] |
| Oil boiler replacement | £4,500 to £5,500 | [1] |
| Installation labour alone | £1,000 to £2,000 | [2] |
These are guide prices from two installer and trade-directory cost guides, not quotes. We have not verified them independently.
How much does a new boiler cost by house size?
| Example home | Likely job | Guide price |
|---|---|---|
| 2-bed flat, old combi in the same place | Like-for-like combi swap | £1,800 to £3,000 |
| 3-bed semi | Mid-range combi swap | £2,300 to £3,500 |
| 4-bed detached, high hot water demand | Larger combi or system boiler | £2,700 to £5,000+ |
| Older house with tanks in the loft | Regular to combi conversion | £3,000 to £5,700 |
Source: Heatable [1]. Boiler output also scales with the home. Checkatrade's sizing table suggests 24 to 27kW for 2 bedrooms and 5 to 10 radiators, and 28 to 34kW for 3 bedrooms and 10 to 20 radiators [2].
The quote page links to a partner quote form. We earn a commission if you request a quote. For UK property owners, 18+.
What affects the price of a new boiler?
- Changing boiler type. Switching from a regular or system boiler to a combi needs new pipework and removes tanks, which is why conversions sit at the top of the table.
- Moving the boiler. A new location adds labour, pipework and a new flue route [1].
- Where you live. Labour is typically dearer in London and the South East [2].
- Extras. Checkatrade lists a magnetic filter at £60 to £160 supply only, plus £50 to £150 to fit, and a wifi heating controller at around £150 [2].
A straightforward like-for-like swap usually takes 4 to 6 hours. A regular to combi conversion takes about 1.5 to 2 days [2].
Worked example: comparing two quotes for the same job
Say a 3-bed semi gets two quotes for a combi swap in the same spot. Quote A is £2,400 and lists the boiler, flue, magnetic filter, chemical flush and controls. Quote B is £2,100 but lists only the boiler and labour.
Using Checkatrade's figures, adding a fitted filter to quote B costs roughly £110 to £310, and a wifi controller about £150 [2]. Quote B could end up at around £2,360 to £2,560 before any flush, so the cheaper headline price may not be cheaper. Ask each installer to price the same list.
What should a boiler quote include?
Heatable suggests checking that each quote covers the same boiler model or equivalent, the warranty length, the flue kit, a magnetic filter, controls, a chemical flush or system clean, any gas pipe upgrade, VAT, Gas Safe registration and removal of the old boiler [1]. If you're paying monthly, ask for the total cost including finance.
What are the red flags in a boiler quote?
- No Gas Safe registration. Gas boilers must be fitted by a Gas Safe registered engineer, and oil boilers by an OFTEC registered technician [2]. You can check an engineer on the Gas Safe Register.
- A price with no itemised list, which makes it hard to compare.
- Pressure to sign on the day or a discount that expires before you can get another quote.
How long does a boiler last?
A boiler typically lasts around 10 to 15 years, depending on the model, maintenance and use [2]. Gas and LPG boilers fitted before 2005 (oil before 2007) are usually non-condensing and lose more heat through the flue [3].
The quote page links to a partner quote form. We earn a commission if you request a quote. For UK property owners, 18+.
Sources
- Heatable, New boiler installation costs 2026, updated 9 October 2026.
- Checkatrade, How much does a new boiler cost in the UK in 2026?, cost tables updated October 2026.
- Energy Saving Trust, Boiler types explained.
All sources checked on 14 October 2026.