How much does a new boiler cost in the UK?
A 2026 guide to combi boiler replacement and installation costs, labour and conversions.
A new boiler is a big-ticket job, and the price depends on the boiler, the type of system and how much work the installation involves. Here are typical 2026 costs for a replacement.
Typical new boiler costs
| Job | Typical cost (2026 guide) |
|---|---|
| Combi boiler (supply + fit, like-for-like) | £1,800–£3,500 |
| Labour only (standard swap) | £550–£800 |
| System / conventional to combi conversion | £3,500–£4,500+ |
| Moving the boiler to a new location | add £300–£600+ |
| Power flush (often recommended) | £300–£600 |
These are typical guide prices for 2026 and will vary by job, property and location. Always get written quotes for your own project before deciding.
What affects the cost?
- The make, model and output of the boiler
- Whether it is a straight swap or the boiler is being moved
- Converting between boiler types
- Extras such as smart controls or a magnetic filter
- The age and condition of the existing system
- London and South East labour rates
Boiler installation costs in London
Installation costs rise in London and the South East due to higher labour rates. If you are replacing an old, inefficient boiler, check whether you qualify for support such as the Boiler Upgrade Scheme.
How to get a fair price
Only a Gas Safe registered engineer may legally work on a gas boiler — always ask to see the ID card. Get a written quote that covers the boiler, labour and any extras, and confirm the manufacturer warranty and whether a power flush is needed.
Frequently asked questions
How long does it take to fit a new boiler?
A straightforward like-for-like combi swap usually takes 4–6 hours and can be done in a day. Converting to a different type of boiler, or moving it, typically takes two days or more.
Who can install a gas boiler?
Only an engineer on the Gas Safe Register may legally work on a gas boiler. Always ask to see the Gas Safe ID card before work begins. For oil boilers, look for OFTEC registration instead.
Should I get a power flush?
If your radiators have cold spots or the system is sludgy, a power flush (around £300–£600) can improve efficiency and is sometimes required to validate a new boiler warranty. A good engineer will advise whether it is needed.
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