How much does a new boiler cost?

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

Read on to find out how much you should expect to pay for a new boiler installation

Make sure your engineer is a trusted expert. You'll depend on them to get your boiler working efficiently in your home, and you'll want to make sure you're happy with what you're paying for.

The cost of a new boiler

The price you pay for a new boiler will vary depending on:

• The type If you're getting a heat-only or storage boiler, there may be extra costs if you need a hot water cylinder fitting.
• The brand/model Although most boiler brands offer models at different price points, some brands are cheaper overall. Getting a reliable boiler is the most important thing to consider when deciding which brand to go for as it will save you money and stress in the long run.
• The size The larger the boiler (in kilowatts) the more expensive it usually is.

To give you an idea of current boiler prices, in the table below we've compiled what you can typically expect to pay for the different types of boiler. 

The price for a boiler can vary depending on the model, its size and the price your engineer can get the boiler for. However, our analysis should give you a sense of typical costs. Contact a boiler manufacturer directly for its latest prices and offers.

If you're a Which? member, you can log in now to unlock the tables. If you're not a member, try Which? today.

Not sure what type you should get for your home? Read our guide to different types of boilers for the pros and cons of each

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Boiler installation costs

The cost of the installation will include the price of the new boiler, a system clean and labour, plus any additional extras you want.

Depending on the amount of work the engineer needs to do to fit the boiler will affect overall costs - for example, if the installer needs to change pipework or alter the location, then you should expect labour costs to be higher.

Where you are in the UK will also affect the prices you pay. While an engineer in London and the South East will probably cost more than an engineer in a lower cost of living region, data also shows that customers living rurally might pay more than customers in some towns and cities because there's less labour supply and competition.

Lots of engineers will quote you for a total sum for the work needed instead of an itemised bill. This reduces admin work for the engineer, installation jobs can't always be broken down meaningfully, and it also avoids the impression that we can pick and choose the work done, which could lead to a bad installation. 

But regardless, even if the engineer only quotes one sum, they should still be able to explain the costs to you, even if this is a verbal conversation you have. 

From the outset, these are some factors that may add or take away from your installation costs: 

• A like-for-like swap, such as swapping a 24kW combi for another, will be easier and cheaper.
• If you need a larger boiler, for example if you've extended your home or converted it to add another bathroom, you may need a bigger supply line to the gas meter (between £100 and £300).
• If you need to relocate your boiler, this will increase costs and necessitate re-piping.
• If you're swapping a combi for a boiler with a hot water tank, you'll pay £300 - £600 for a vented cylinder or £900 - £1,300 for an unvented cylinder, depending on the size of the cylinder
• If you're swapping from a heat-only or a system boiler to a combi, a common swap, an extra £300 to £650 can be expected for the labour and re-piping. 
• If you're installing smart heating controls for your boiler, you're looking at £100 and £250 for a smart thermostat, and £35 to £80 per smart radiator valve. A normal thermostatic radiator valve is about £15. 
• If your heating system is cleaned (important so that your new boiler can run efficiently), you can expect a power flush, used to clean heavily sludged systems. This will range in cost from £300 to £750 for a five-radiator system, with an average cost of £500.

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 boilers are now the most common type of boiler in the United Kingdom. 

We've combined the findings from a Delta-EE report with our boiler pricing in the table below to give you a rough price range (with an average price in brackets) for what you should expect to pay for different combi boiler installations.

Only Which? members can log in to unlock the tables and find out how much you should expect to pay to install a new combi boiler. If you're not a member, try Which? today and you'll get access to the prices we would expect an engineer to charge for installing a combi boiler.

If you want a new combi boiler, make sure you read our combi boiler reviews so you buy the most reliable brand

Heat-only boiler installation costs

Heat-only, 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 or multiple bathrooms. 

If you don't already have a hot water cylinder in your home or wish to replace an existing one, this can cost from £300 for a lower-capacity and poorly insulated cylinder up to £600 for one with a higher capacity and that's highly insulated (BEIS report, 2020).

We have combined the findings from the BEIS 2020 report, for labour costs and fittings, with our boiler pricing in the table below to give you a rough price range (with an average cost in brackets) for what you should expect to pay for different combi boiler installations.

Only Which? members can log in to unlock the tables and find out how much you should expect to pay for your heat-only boiler replacement. If you're not a member, try Which? today and you'll get access to the prices we would expect an engineer to charge for installing a heat-only boiler.

If you're looking for a new regular boiler, also known as a heat-only model, make sure you check our regular boiler reviews

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. As such, the hot water cylinder needed for a system boiler is an unvented one (sometimes called 'closed vent' or 'sealed'). These typically cost £900 for a for a lower-capacity and poorly insulated cylinder up to £1,300 for one with a higher capacity and that's highly insulated (BEIS report, 2020).

We've combined the findings from the BEIS 2020 report, for labour costs and fittings, with our boiler pricing in the table below to give you a rough price range (with an average cost in brackets) for what you should expect to pay for different combi boiler installations.

Only Which? members can log in to unlock the tables and find out how much you should expect to pay for your heat-only boiler replacement. If you're not a member, try Which? today and you'll get access to the prices we would expect an engineer to charge for installing a heat-only boiler.

Head to our system boiler reviews if you're looking for a new system model.

Oil boiler installations

Installation of the following oil systems should be carried out by a trained professional:

• 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 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; 0345 543 0330
• oftec.co.uk; 01473 626298

Like gas boilers, you can expect lower installation costs if you're directly swapping your current oil boiler for a similar model. If you're swapping the type of boiler, relocating where your oil boiler is or needs a lot of old fittings replacing, then the costs will increase.

Additionally, you may have to install an oil store (including piping from the store to the boiler). Smaller oil stores, suitably for smaller boilers and houses that have easier access to oil supplies typically cost around £1,300. If your home has a larger oil boiler, or is in a remote location where you'll want a larger store to ensure you have a fuel supply, this will cost around £2,400 (BEIS report, 2020).

We've combined the findings from the BEIS 2020 report, for labour costs and fittings, with our boiler pricing in the table below to give you a rough price range (with an average cost in brackets) for what you should expect to pay for different combi boiler installations.

Only Which? members can log in to unlock the tables and find out how much you should expect to pay for your heat-only boiler replacement. If you're not a member, try Which? today and you'll get access to the prices we would expect an engineer to charge for installing a heat-only boiler.

Head to our oil boiler reviews if you're looking to get an oil boiler installed

Boiler financing - how you can pay for a boiler and installation 

Unfortunately, most boiler swaps are emergencies we don't expect and an unavoidable expenditure. You have a lot of options when it comes to paying for a new boiler and installation.

Anything that involves paying interest on a loan is best avoided. Fortunately, you have a lot of ways to pay for a boiler plus installation without resorting on a high-interest loan.

We don't endorse any of the options below, but it can help you to understand your options. What we do recommend is making sure you're resilient enough to avoid expensive financing options by ensuring you could pay off a boiler and installation within four years at the most.

The government offers grants for consumers to ditch their gas and oil boilers to get heat pumps and biomass boilers instead. Read about boiler grants to find out more.

Pay up-front

If you have the money, it's probably best to get a few quotes from local engineers and opt for the one you trust who has good reviews. Use our figures as a guide, but bear in mind that there will be regional differences, the costs will depend on the design of your system and what's needed, and the impacts of high inflation will see some costs going up.

0% APR finance

If you need to borrow to afford your boiler, it's a better deal if you can avoid interest on the loan. The downside is that the term for paying the loan will be shorter than finance options with interest charges (two years is a common timeframe). 

Which? Trusted Trader Heatable offers £0 deposit, 4 years 0% APR. 

Other companies offering 0% APR at the moment include British Gas  iHeat (£0 deposit, 2 years, 0%APR), Warmzilla (£0 deposit, 2 years 0% APR).

But it's important to search around and make sure you're happy with the terms of the loan. 

You may be able to pay a deposit with cash you already have and then pay smaller instalments over the term. For example, if you swap a combi boiler with another combi for £2,600 and you're able to pay £1,000 up-front, a 0% interest loan paid over three years will be approximately £44/month instead of £72/month. 

Boiler finance

Engineers, companies and energy suppliers may offer boiler finance over all sorts of terms, possibly even allowing you to pay the boiler off for a decade. 

But generally speaking, the longer you take to pay off the loan, the more interest you'll be paying. This is why, if at all possible, paying up-front or getting a 0% interest loan over a shorter period is better.

For example, E.ON Energy offers a 10 year loan at 7.9% APR. British Gas offers 10 years at 9.9% APR.

This is an option of last resort because the interest charges are high. To avoid relying on this sort of financing, it's best to stress test your finances and make sure you could pay off a boiler within four years minimum. 

Why a reliable boiler is important

Although it depends on the faulty part, on average it costs £200 each time a boiler needs fixing. With that in mind, it doesn't take long for repair costs to stack up and that's not accounting for the inconvenience of days without heating and hot water. 

In our 2022 survey, we asked 9,722 members of the general public, who had bought a boiler in the past six years, when their boiler needed it's first repair (if it's needed one at all). 

The graph below shows the percentage of boilers that remain fault-free in the first six years after installation. 

Over the course of your boiler's life, a reliable boiler brand will save you money compared with going for a less reliable one. Our survey findings show that it isn't just the biggest boiler brands that are reliable – you can get more affordable boilers from companies with great reliability. 

Read our best gas and oil boiler brands guide to discover the most and least reliable brands

Finding a registered boiler installer

You should always get a gas boiler installed by a gas safe-registered engineer. The Gas Safe Register provides 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're qualified to do.

Which? Trusted Traders are vetted heating engineers who are all gas safe registered. As such it should be your first port of call for finding a registered boiler installer.

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 best boilers guide. If you're unsure what type you need, take a look at our guide to different types of boiler.

You can use our Which? Trusted Traders search tool below to find a reliable local tradesman near you, you don't have to be a Which? member to use Which? Trusted Traders.