How much does a new boiler cost?

A new boiler is one of the bigger bills most homeowners face, and it often arrives at the worst moment, in the middle of winter with no heating. Knowing the going rate, and what pushes a quote up, helps you tell a fair price from a high one and ask the right questions before you sign. This guide uses figures from sources that do not sell boiler leads, explains the rules every new gas boiler has to meet, and shows how to compare quotes.

All prices are averages and ranges, not quotes. The only way to know what your boiler will cost is to have two or three Gas Safe registered engineers look at your home and price the same job.

Average cost of a new boiler in 2026

The average new gas boiler, including installation, is £3,700, according to the Energy Saving Trust, as reported by Which? in September 2026. Which?'s boiler price guide gives a wider range of around £1,400 to £7,000 for a boiler supplied and fitted.

The range is wide because the boiler itself is only part of the price. Labour, the flue, pipework, controls, a system clean and the warranty all go into the total, and they vary far more between homes than the boiler does.

Which type of boiler do you have?

• Combi boiler. Heats water on demand, with no hot water cylinder or tanks in the loft. The most common type in UK homes, and usually the cheapest to replace like for like.
• System boiler. Works with a hot water cylinder, usually in an airing cupboard, but no loft tanks. Suits homes with more than one bathroom in use at once.
• Heat only (regular) boiler. Works with a cylinder and cold water tanks in the loft. Common in older homes.

Replacing a boiler with the same type in the same place is almost always the cheapest option. Changing type is where the price climbs.

What extra work costs

Which? lists the costs that most often get added to the price of the boiler itself. These are its figures; your engineer's quote may differ.

A bigger gas pipe is often needed because a modern combi can burn more gas at full output than the old pipe from the meter was sized for. A powerflush is not always needed, but a new boiler should go into a clean system. Our guide on how to bleed a radiator covers the signs of sludge, such as radiators cold at the bottom.

What pushes the price up

• Moving the boiler. Which? says relocating a boiler costs more because it needs new pipework, and often a new flue and condensate pipe.
• Changing type. Converting to a combi, or going the other way and adding a cylinder, adds labour and parts.
• A bigger boiler. A larger house with more radiators and bathrooms needs a higher output boiler, which costs more.
• Where you live. Which? says prices are higher in London and the South East, and can also be higher in rural areas.
• The warranty. Boilers with a longer manufacturer warranty usually cost more. Warranties usually depend on the boiler being registered and serviced every year, so check the terms.
• Urgency. A boiler that has failed in a cold snap leaves less time to compare quotes. If you can, start getting prices while the old boiler still works.

VAT and grants

VAT on a new boiler

HMRC treats energy efficient boilers as standard rated for VAT, so a VAT registered installer adds 20 percent. That is different from heat pumps, which are zero rated in Great Britain until 31 March 2027. A grant funded heating installation for some older or lower income households can qualify for a reduced rate. A business only has to register for VAT once its taxable turnover goes over £90,000 a year, so always ask whether a quote includes VAT.

Is there a grant?

There is no national grant for replacing a gas boiler with another gas boiler. The Boiler Upgrade Scheme in England and Wales gives £7,500 towards an air or ground source heat pump, and £5,000 towards a biomass boiler, but nothing towards a gas boiler. Some households on low incomes or certain benefits can get help through energy company or council schemes. The GOV.UK energy efficiency service, or 0800 098 7950, shows what is available where you live. If you are weighing up the switch, our guide on whether to get a heat pump or a new boiler compares fitted prices and running costs.

The rules every new gas boiler must meet

A Gas Safe registered engineer

By law, anyone fitting or working on a gas appliance in your home must be on the Gas Safe Register, as the HSE explains. Check the engineer on the Gas Safe Register before they start, and ask to see their ID card, which lists the work they are qualified to do. A badly fitted boiler can leak carbon monoxide, which you cannot see or smell.

Boiler Plus controls in England

Since April 2018, the government's Boiler Plus standard requires every gas boiler fitted to an existing system in England to be at least 92 percent efficient (ErP), and to come with time and temperature controls if they are not already there and working. A combi replacement also needs one extra energy saving measure: weather compensation, load compensation, a smart thermostat with automation and optimisation, or flue gas heat recovery. Wales and Scotland have their own rules. A quote should say which measure is included.

Building regulations

Fitting a new boiler is notifiable building work. Because Gas Safe Register runs a competent person scheme, a registered engineer notifies building control for you, so you do not need to apply yourself (GOV.UK). You should then receive a Building Regulations Compliance Certificate. Keep it, because a buyer's solicitor will ask for it when you sell.

Repair or replace?

A new boiler is not always the answer. If one part has failed on an otherwise reliable boiler, a repair is usually far cheaper. Think about replacing it when it keeps breaking down, when parts are no longer made for it, or when a repair quote is a large share of the cost of a new one. Our guide to what a boiler repair costs sets out typical prices, and what to do when your boiler breaks down covers the checks to make before you call anyone.

A newer boiler can also cut your bills if the old one is an older non condensing model. Gas costs 7.97p per kWh on average on the Ofgem price cap from 1 October to 31 December 2026, so efficiency matters over a long winter. Once it is in, an annual service keeps the warranty valid: see what a boiler service costs.

How to get a fair price

1. Note what you have now: the boiler make and model, whether it is a combi, where it is fitted and how many radiators and bathrooms you have. Photos of the boiler, flue and gas meter help.
2. Decide on type and position before you ask for quotes, so every engineer prices the same job.
3. Get two or three itemised quotes listing the boiler model, flue, pipework, flush, controls, removal of the old boiler, notification, warranty and VAT. Citizens Advice explains that a quote is a fixed price, while an estimate can change.
4. Check the controls meet Boiler Plus, and which extra measure a combi comes with.
5. Check the engineer on the Gas Safe Register. Our guide on how to check a tradesperson is genuine shows how in a couple of minutes.
6. Get the paperwork: the commissioning checklist, warranty registration and the Building Regulations Compliance Certificate.

Get a price for a new boiler

Post your boiler job free, saying what boiler you have now, where it is and whether it still works, and hear back from a local heating engineer with a price. You pay the business directly, and nothing is taken online.

Or browse local businesses first: heating engineers in Birmingham, Wolverhampton, Coventry, Dudley, Walsall or Solihull. For more guides on heating and costs, see all our home advice.