How much does a new boiler cost in 2026?

Most UK homeowners pay between £1,800 and £4,000 for a new boiler, fitted. That is a wide range, and the reason is simple: the boiler is often the cheaper half of the job.

A straight swap, taking out an old combi and putting a new one back in the same place on the same pipework, is a day's work for one engineer. Moving the boiler from the kitchen to the loft, or converting a conventional system with a hot water cylinder and header tanks over to a combi, is two or three days and a lot more copper.

What you are actually paying for

The boiler itself is typically £700 to £1,600 depending on brand and output. Labour is usually £500 to £1,200. Then there is the flue, the fittings, a magnetic system filter, a chemical flush or a full power flush, and possibly new radiator valves.

Two things push a quote up sharply. The first is moving the boiler, because that means new gas, water and condensate runs, plus making good the old location. The second is converting between system types, because you are ripping out tanks and re-plumbing the hot water.

Why quotes differ by hundreds

Installers price the same job differently because they are pricing different things: their day rate, their supplier discount on the boiler, how much of the old system they intend to replace, and how busy they are that month.

This is exactly why comparing is worth the sixty seconds. It is common to see £600 to £800 between the highest and lowest quote on an identical job. The cheapest is not automatically the worst, and the dearest is not automatically the best.

Questions worth asking every installer

Is the quote fixed, or an estimate that can move? Does it include a power flush or just a chemical clean? Is a magnetic filter included, since most manufacturer warranties require one? Who registers the boiler with the manufacturer and Gas Safe, and who notifies building control?

Get the answers in writing. A good installer will not mind being asked.