How much does a new boiler cost?
Published guides put a straightforward like for like combi swap, fully installed, at £1,800 to £4,500, and most converge on £2,200 to £3,000 for a standard 3 bed semi. Moving the boiler, changing boiler type or converting to a combi pushes the price materially higher.
£1,800–£4,500 fully installed for a like for like swap
The published figures
Every figure below is a published guide figure, shown as its publisher printed it and linked to the source. Retrieved on 17 July 2026.
| What | Published figure | Basis | Source |
|---|---|---|---|
| Like for like boiler swap, fully installed | £1,800–£4,500 | supply and installation | Checkatrade cost guide (opens in new tab) |
| Combi boiler installation in a 3 bed semi | £2,200–£2,800 | Checkatrade cost guide (opens in new tab) | |
| Average combi boiler, supply and install | around £3,000 | Checkatrade cost guide (opens in new tab) | |
| Conversion to a combi from a system or conventional boiler | around £4,000 | supply and installation | Checkatrade cost guide (opens in new tab) |
| Installation labour | £500–£1,500 | labour only | MyBuilder price guide (opens in new tab) |
| System power flush, as an add on | £450–£800 | MyBuilder price guide (opens in new tab) | |
| Fixed price combi to combi swap | from £1,790 | fully installed, including flue, disposal and a smart thermostat | BOXT fixed price installation (opens in new tab) |
What moves the price
- Boiler type: combi, system or conventional
- Like for like swap versus relocating the boiler or converting the system
- Property size and hot water demand: bedrooms, bathrooms, radiators
- Brand and warranty length
- Extras: new controls, radiators, a power flush
Get real quotes
Guide figures set expectations; only quotes set your price. Compare local businesses on their public evidence:
Sources
- Checkatrade cost guide (opens in new tab) (directory site, published 2026)
- MyBuilder price guide (opens in new tab) (directory site, published 2026)
- BOXT fixed price installation (opens in new tab) (installer, undated)
Figures retrieved from the named sources above on 17 July 2026. Prices change; always confirm with quotes.
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