Heating Engineer · New boiler
How much does a new boiler cost?
What a new gas boiler costs supplied and fitted in the UK in 2026, what changes the price, what a proper installation includes and how to get an accurate quote from a heating engineer.
per boiler, supplied and fitted
Published UK trade day rates and merchant material prices, September 2026. Not yet based on Hard Hat Way quote data.
What changes the price
- Boiler type. A like-for-like combi swap is the cheapest; going from a system or regular boiler to a combi is a bigger job
- Boiler brand and size. Premium brands and higher-output models cost more, and often carry longer warranties
- Moving the boiler. Relocating it to a different wall or room means new gas, water and flue runs
- Flue route. A straight flue through the wall is simple; a long vertical flue through a roof is not
- System condition. A powerflush, new magnetic filter or replacing old radiator valves may be needed to protect the warranty
- Controls. Smart thermostats and zoned heating add to the parts and the wiring
A new boiler is one of the most common home jobs and one of the easiest to get quoted wrong, because the price of the box on the wall is only part of it. What you’re paying for is a gas-safe installation: the boiler, the flue, the pipework, the controls, the commissioning and the paperwork.
What drives the price
The type of swap matters most. Replacing an old combi with a new combi in the same place is the simplest job, often done in a day. Changing from a regular boiler with tanks in the loft and a cylinder in the airing cupboard to a combi means removing all of that, rerouting pipework and is usually a two-day job with more parts.
The boiler itself ranges widely. A standard model from a mainstream brand at the bottom end, premium brands and higher outputs for bigger houses at the top.
Where it goes is the next factor. Same wall, same flue hole, easy. New location means new gas pipe, new water pipes, condensate drain and a new flue route, and a flue that has to go up through a roof rather than straight out of a wall is a bigger job again.
Then the system around the boiler. If the radiators and pipes are full of sludge, a new boiler can be damaged by it, and many manufacturers want a powerflush and a magnetic filter fitted to honour the warranty.
What a good job includes
- A boiler sized for your house, not just the biggest one on the van
- The old boiler removed and disposed of, and any tanks or cylinder taken out if you’re going combi
- Gas supply checked for the new boiler’s demand and upgraded if the pipe is too small
- Flue installed to the manufacturer’s rules, with the right clearances from windows and boundaries
- Condensate pipe run to a drain and insulated if it’s outside
- System flushed or cleaned, and a magnetic filter fitted on the return
- Controls fitted and explained to you
- Boiler commissioned, the benchmark checklist filled in, and the installation registered with Gas Safe so you get a Building Regulations certificate
- Warranty registered with the manufacturer in your name
How to get an accurate quote
Photograph the existing boiler with its label visible, the pipework underneath it, the flue where it leaves the house, and any tanks or cylinder. Say how many bedrooms and bathrooms you have and whether you want the boiler to stay where it is. That’s enough for an honest starting price. A heating engineer will confirm the final price after a site visit, when they can check the gas supply, the flue route and the condition of the system.
These are guide figures, not a promise. Post the job with photos and get real quotes from local Gas Safe heating engineers whose work is rated by other engineers.
Common questions
Should I replace a working boiler?
If it's over 12 to 15 years old, non-condensing, breaking down regularly or parts are getting hard to find, replacing it usually makes sense. A modern condensing boiler is more efficient and comes with a long warranty. If it's under ten years old and running well, a service is normally the better spend.
What's the difference between a combi and a system boiler?
A combi heats water on demand and needs no tank or cylinder, which suits most flats and smaller houses. A system or regular boiler heats a cylinder of stored hot water, which is better for larger homes with more than one bathroom in use at once. Your engineer will ask how many bathrooms and people you have before recommending one.
Do I get a warranty?
Most manufacturers offer warranties of several years when the boiler is fitted by an installer accredited with them, and many require an annual service to keep it valid. Ask what the warranty is, who registers it, and what you have to do to keep it.
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