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Buying a new boiler

How much does a new boiler cost?

By Matthew Knight

Article 3 of 6

Find out how to get a new boiler installed and how much it should cost. We'll help make sure you don't get overcharged for your boiler installation.

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Boiler installation costs vary enormously, depending on how much work is required, the parts needed, their availability, where you live and who you employ for the job.

A recent snapshot investigation, where our boilers expert arranged for 10 quotes to replace his own boiler, found that they can vary by as much as £3,200. 

All 10 of the quotes received were for an old non-condensing regular boiler to be replaced with a modern condensing boiler. Each of the quotes also included the installation of 10 thermostatic radiator valves, a full chemical powerflush, system balancing, MagnaClean filter, a new circulation pump and a new hot water cylinder thermostat.

Ultimately, our expert ended up paying just less than £2,500 for his boiler replacement.

If you're a Which? member, you can log in now to unlock the tables on this page and find out how much you should expect to pay for your boiler replacement. You'll get access to the prices we would expect an engineer to charge for installing any type of boiler. 

Before you buy a new boiler, make sure you read our guide on how to get the best boiler installation, and make sure you buy a boiler that will last by getting one from the best boiler brands.

New boiler costs

The price you pay for a new boiler will vary depending on the type, brand and model of boiler you choose. In the tables below, we've displayed a range of prices for new boilers, and this covers all boilers of that type that are on the market in the UK. To get an accurate price for the model of boiler you're interested in, take a look at our boiler reviews

To give you an idea of current boiler prices, we show you in the table below what you can typically expect to pay for different types of boiler including combi, system heat-only and system boilers. 

Boiler prices table

Type of boiler Price range
Gas combi
Gas heat-only
Gas system
Oil combi
Oil heat-only
Oil system

Table notes
1 Table last updated in May 2017. Price range is the highest and lowest price of a boiler of each type from all the boiler manufacturers in the UK with a greater than 1% market share.


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Because this is only a snapshot, you should contact a boiler manufacturer directly for its latest prices and offers. Boiler prices vary according to the heat output of the boiler; in general, a boiler with a larger heat output that is more suitable for a larger home, will cost more than a boiler with a smaller heat output.

Boiler installation costs

The cost of the installation will also vary depending on the amount of work the engineer needs to do to fit the boiler. If the installer needs to change pipework or alter the location of the boiler, this will add to the overall cost of the installation displayed in the table below.

As well as paying for labour, the cost of the new boiler and a system cleanse, we would always recommend that you consider adding a filter, such as a MagnaClean, that will keep your system free of gunk long after the heating engineer has left. This should add between £100 and £200 to the cost of installation.

Thermostatic radiator valves (TRVs), which cost from around £15 per radiator, can also be an effective way to keep your system balanced and room temperatures comfortable. They can also lead to lower heating bills if used correctly, as they can prevent rooms you don't use very often from being overheated. 

If you're unsure what type or size of boiler you need, read our guide on how to buy the best boiler

Combi boiler installation costs

Combi boilers are great for smaller homes or flats that typically have one bathroom. A combi boiler heats water on demand and doesn't require a large hot water cylinder or feed tank.

Combi boiler costs
Scenario Cost of labour Cost of boiler System cleanse Total cost
Replacing an existing combi boiler with a new combi in the same location
Replacing a conventional heat-only boiler with a condensing combi boiler
Table notes
1 We teamed up with the Association of Plumbing and Heating Contractors (APHC) to show you the typical price ranges you should expect to pay.


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If you want a new combi boiler, make sure you read our combi boiler reviews so you buy the most reliable brand, which is half as likely to develop a fault in the first six years as the least reliable brand. 

Heat-only boiler installation costs

Heat-only, or gravity-fed or regular, boilers require a hot water cylinder, usually in an airing cupboard, plus a cold water feed tank typically found in the loft. The two tanks means they're most suitable for larger homes. Because the hot water they produce is stored in a cylinder, they can provide a large amount of hot water to many taps at the same time – ideal if you have a big family and multiple bathrooms. 

Heat-only boiler costs
Scenario Cost of labour Cost of boiler System cleanse Total cost
Replacing a regular non-condensing boiler with a regular condensing boiler in the same location
Installing a new gas condensing boiler in a different location
Table notes
1 We teamed up with the Association of Plumbing and Heating Contractors (APHC) to show you the typical price ranges you should expect to pay.


Member Content

System boiler installation costs

A system boiler is just like a regular boiler, except that it doesn't need a large cold water feed tank for operation. For a guide price on system boiler installations, we would recommend looking at the regular boiler costs in the table above and adding £200-£400 to cover the additional costs of a system boiler. 

System boilers are pressurised, so they're great if you live in a home that has poor mains water pressure. They're also brilliant if don't have enough space for a cold water feed-tank, or if you're having a loft conversion and want to remove the tanks. 

Head to our system boiler reviews if you're looking for a new system boiler, and make sure you buy one from one of the most reliable brands.

Why a reliable boiler is important

Every time your boiler breaks down, it costs on average £200 to get it fixed. With that in mind, it doesn't take long for repair costs to stack up, and that's ignoring the inconvenience of days without heating and hot water. 

Our annual boiler reliability survey of more than 10,000 boiler owners reveals the brands that will keep you warm all winter – and the ones that will let you down.

The graph below shows the percentage of boilers that remain fault-free in the first six years after installation. The least-reliable brand is twice as likely to develop a fault as the most reliable. 

Make sure you buy a boiler from one of the most reliable brands.

Finding a registered boiler installer

Which? Trusted Traders should be your first port of call for finding a registered boiler installer. All Which? Trusted Traders must meet our exacting standards in order to register on the scheme, so it's a reliable place to look for a high-quality installation, service or repair to your boiler.

Before you call an installer, make sure you've got a good grounding in what to expect when you get a new boiler. Check out our quick and easy guide - 5 things you need to know before you buy a new boiler. If you're unsure what type of boiler you need, take a look at our guide to combi boilers, which compares this kind of system with the others.

Boiler installations by Gas Safe-registered engineers

The Gas Safe website will provide details of registered installers in your area. Alternatively, call Gas Safe on 0800 408 5500. Each installer must carry an ID card, which lists the gas work they are qualified to do. 

Check that it covers the work you're expecting and includes the words 'energy efficiency'. You can also check their registration with Gas Safe.

Oil boiler installations

Installation of the following oil systems should be carried out by a competent person:

  • an oil-fired combustion appliance, which has a rated heat output of 100kW or less, and which is installed in a building with no more than three storeys (excluding any basement) or in a dwelling
  • oil storage tanks and the pipes connecting them to combustion appliances
  • heating and/or hot water service systems connected to an oil-fired combustion appliance.

Several schemes, listed below, exist to help you track down a suitable competent person for oil appliances. You can find more details on these websites:

  • aphc.co.uk (Association of Plumbing and Heating Contractors (Certification) Limited 0121 711 5030
  • besca.org.uk (BESCA Limited) 0800 652 5533
  • napit.org.uk 0870 444 1392
  • niceic.com 0800 013 0900
  • oftec.org.uk 0845 658 5080