How Much Does a New Boiler Cost to Install? A Straight Answer

Typical price ranges for a new boiler

For most homes in and around Hamilton, a straightforward like-for-like combi boiler swap, where the new boiler goes in the same spot as the old one, tends to fall somewhere between £1,800 and £3,000 fully installed. That usually covers the boiler itself, a new flue, a magnetic filter, a chemical flush of the system, and the labour.

Bigger jobs cost more. Converting from a conventional boiler with tanks and a hot water cylinder to a combi typically runs £3,000 to £4,500, because there's new pipework, the old cylinder and loft tanks to strip out, and often a day or two of extra labour. A system boiler with an unvented cylinder, which suits larger households, usually lands in a similar bracket. Moving the boiler to a different room adds several hundred pounds on top of any of these figures.

• Like-for-like combi swap: roughly £1,800 to £3,000
• Conventional to combi conversion: roughly £3,000 to £4,500
• System boiler with new cylinder: roughly £3,000 to £4,500
• Relocating the boiler: typically £300 to £800 extra

What actually pushes the price up or down

The boiler brand and model is the obvious one. Budget boilers can be £600 to £900 at trade, while premium models with 10 or 12 year warranties are £1,000 to £1,600. The premium units generally justify themselves in build quality and warranty length, but a mid-range boiler installed properly will outlast a top-end boiler installed badly.

The condition of your existing system matters just as much. Older houses in this area, particularly the sandstone tenements and post-war stock around Hamilton, Blantyre and Larkhall, often have tired pipework, sludged-up radiators, or old imperial-sized pipe that needs adapting. If your system needs a powerflush rather than a standard chemical clean, expect an extra £300 to £500. Upgrading the gas supply pipe, which is common when replacing boilers over 15 years old, can add £150 to £400.

What should be included in a proper quote

A written quote should itemise the boiler make and model, the flue, a system filter, a cleanse or flush, removal of the old boiler, and commissioning. It should also confirm the installer is Gas Safe registered, which is a legal requirement for any gas boiler work in the UK, and that the boiler will be registered with the manufacturer to activate the warranty and notified to the local authority through Building Standards.

Be wary of quotes that are vague about the model, quote a suspiciously low headline price, or come from someone who priced the job without asking about your water pressure, radiator count, or hot water usage. A combi that's undersized for a busy family home is a common and expensive mistake, and it's usually the result of a rushed survey.

• Boiler make, model and warranty length in writing
• Flue, filter, flush and controls itemised
• Gas Safe registration number on the paperwork
• Warranty registration and Building Standards notification included

Is it worth paying more for a longer warranty?

Usually, yes. The difference between a boiler with a 5 year warranty and one with 10 or 12 years is often only £300 to £500 on the total job, and a single out-of-warranty repair with parts can easily cost that. Most long manufacturer warranties require an annual service to stay valid, which you should be doing anyway, so the real cost of keeping cover alive is minimal.

One caveat: warranties are only as good as the installation. Manufacturers can refuse claims if the system wasn't flushed or filtered at install, which is another reason a slightly cheaper quote that skips those steps is a false economy.