Figuring out the cost of a new boiler in 2025 can feel like wrestling a spider web off your face - confusing, frustrating, and a bit sticky.
At Heatable, we’ve fitted over 50,000 boilers across the UK, from straightforward combi swaps to full-on back boiler conversions, so we know the drill.
In this guide, we’ll break down the costs, covering everything from the boiler itself to installation fees, sneaky extras, and what impacts your final bill. Whether you’re upgrading an old, creaky system or starting fresh, we’ll help you budget with clear, up-to-date prices and a few insider tips to save you some cash.
Top Tip: You’re not tied to buying your boiler from your gas or energy provider - freedom’s yours! As an independent provider, Heatable shines with over 11,000 Trustpilot reviews averaging 4.8, outpacing the big names, and we’re proud to be a Which? Trusted Trader. Choosing us means smarter savings and a hassle-free experience.
Quick Summary:
Average Cost: A typical new boiler installation ranges from £2,500 to £3,500, but it’s just the starting point!
What Affects the Price: Your final cost depends on your UK location, boiler type (combi, system, etc.), and the brand or model you pick - every home’s a bit different.
Save with Grants: If you’re on benefits, you could snag a subsidised boiler through the ECO4 scheme - check your eligibility to cut costs.
Energy Savings: Upgrading from a G-rated to an A-rated boiler could save you up to £385 a year - hello, extra cash!
Tailored to You: The exact cost hinges on your unique setup, so a custom quote is the way to go.
Get Your Quote: Ready for clarity? Grab a free, personalised quote in seconds from Heatable - trusted by over 11,000 reviewers with a 4.8 Trustpilot score and a Which? Trusted Trader badge - click here!
New Boiler Costs at a Glance
In 2025, a new boiler with installation typically costs between £1,500 and £5,500, depending on the type, brand, and how tricky the job is. For something more eco-friendly, like a biomass boiler, you’re looking at £10,000–£18,000. Here’s a quick rundown of average costs by boiler type:
Boiler Type | Average Cost (with Installation) |
Combi Boiler | £1,500 - £4,500 |
System Boiler | £1,700 - £5,000 |
Conventional Boiler | £1,700 - £4,500 |
Oil Boiler | £2,500 – £5,500 |
Electric Boiler | £1,700 - £4,500 |
Biomass Boiler | £10,000 - £18,000 |
Factors Affecting New Boiler Cost in 2025
The cost of a new boiler isn’t a one-size-fits-all deal - it’s more like ordering a coffee with all the extras, where every choice bumps up the price. Here’s what can nudge your bill up (or down):
Boiler Type: Combi boilers are usually the cheapest to install since they’re compact and don’t need extra tanks. Biomass boilers, on the other hand, are the priciest due to their complexity and size.
Brand: Big names like Worcester Bosch or Viessmann cost more but come with better reliability, efficiency, and longer guarantees - think of it as paying for peace of mind.
Output (kW): Bigger homes with more bedrooms and bathrooms need a boiler with a higher output, which means a higher price tag.
Installation Complexity: A simple combi swap might take a day, but converting a regular boiler to a combi or moving the boiler to a new spot can add days of labour and extra pipework.
Location: Labour costs vary across the UK. In London, you’ll pay more than in the Midlands or rural areas - sometimes a lot more.
Extras: Fancy a smart thermostat to control your heating from your phone? Or a longer guarantee for added security? These add-ons can increase your total.
Condition of Your Current System: If your existing pipework is ancient (think lead pipes or ones that predate the internet), you’ll need upgrades, which can add to the cost.
Prefer video? Check out our YouTube video explaining the average new boiler costs below:
Average New Boiler Costs by Type
Let’s break down the costs for each boiler type in 2025, with a bit more detail to help you decide what’s right for your home.
1. Combi Boiler Costs
Key details:
Price Range (with Installation): £1,500–£4,500
Average Cost: £3,000
Best For: Small to medium homes with limited space.
Combi boilers are the UK’s most popular choice, and for good reason - they’re a bit like the Usain Bolt of heating: fast, efficient, and versatile. They provide both heating and hot water on demand without needing a separate cylinder or tank, making them ideal for flats or smaller homes with one bathroom.
A straightforward combi swap (replacing an old combi with a new one) is usually the cheapest option, starting at around £1,500. But if your installation is more complex - say, you’re in a listed building or need extra pipework - you could be looking at the higher end, closer to £4,500.
Why Choose a Combi?
Space-saving: No need for a cylinder or tank, so it’s perfect for smaller homes.
Energy-efficient: Only heats water when you need it, saving you money on bills.
Quick to install: Often done in a day for a simple swap, meaning less disruption.
Watch Out For:
Not ideal for larger homes with multiple bathrooms, as the flow rate might struggle with simultaneous showers.
If you’re converting from a regular boiler, costs will be higher (more on that below).
In areas with low water pressure, a combi might not perform as well - check with your installer first.
Combi boilers are the home heating dream that the human race has been striving towards since the discovery of fire.
Curious to know which boiler brand performed worst? Find out in our report on the worst boilers.
2. System Boiler Replacement Cost
Key details:
Price Range (with Installation): £1,700–£5,000
Average Cost: £3,300
Best For: Larger homes with high hot water needs.
System boilers are a step up from combis in terms of power, making them perfect for bigger homes with multiple bathrooms. They work with a hot water cylinder (usually tucked away in an airing cupboard) to store hot water, so you can run several taps or showers at once without losing pressure.
The boiler itself might cost £500–£2,500, but installation can push the total to £5,000 if you need a new cylinder or if the job is complex (e.g., upgrading pipework or adding new controls). If your home already has a cylinder in good condition, you’ll save a bit - expect to pay around £200–£500 for a new cylinder if needed.
Why Choose a System Boiler?
Great for homes with 2+ bathrooms, as it can handle high demand.
Stores hot water, so you won’t run out during a busy morning.
Works well with solar thermal systems, making it a greener choice if you’re thinking long-term.
Watch Out For:
Needs space for a cylinder, so not ideal for small flats or homes with limited storage.
More expensive than a combi if you’re starting from scratch, especially if you need a new cylinder.
Installation can take longer - up to 2 days if the pipework needs adjusting.
3. Conventional/Regular Boiler Cost
Key details:
Price Range (with Installation): £1,700–£4,500
Average Cost: £3,000
Best For: Big homes with multiple bathrooms or low water pressure.
Also known as regular or heat-only boilers, conventional boilers are the traditional option, often found in older or larger homes. They need both a hot water cylinder and a cold water tank (usually in the loft), which makes them more complex to install.
They’re a good fit if you’ve got a big house with high hot water demands or if your water pressure is low, as they can handle multiple taps running at once. Costs can vary depending on the brand and size of the boiler, as well as whether your existing tanks need replacing. A new cylinder costs £200–£500, and a cold water tank can add another £100–£300 if it’s needed.
Why Choose a Conventional Boiler?
Perfect for homes with traditional heating systems that can’t handle high-pressure boilers.
Handles high hot water demand with ease - great for families.
Ideal for areas with low water pressure, as it doesn’t rely on mains pressure.
Watch Out For:
Takes up more space due to the cylinder and tank, so not great for compact homes.
Installation can be more expensive if your current setup needs a lot of work, like replacing tanks.
Less energy-efficient than combi or system boilers, as heat can be lost from the cylinder.
4. Electric Boiler Costs
Key details:
Price Range (with Installation): £1,700–£4,500
Average Cost: £2,500
Best For: Homes without gas, looking for a greener option.
Electric boilers run on electricity (obviously) and are a good choice if you don’t have access to gas or want a more eco-friendly option. They can be combi, system, or regular boilers, and they’re usually cheaper to install than gas boilers because there’s no need for a flue or gas pipework.
Prices start at £600 for the boiler, with total costs averaging £2,500 including installation. However, running costs can be higher since electricity is pricier than gas in most parts of the UK - expect £1,000–£2,000 a year compared to £500–£1,000 for a gas boiler.
Why Choose an Electric Boiler?
No gas? No problem - perfect for off-grid homes or flats.
Low maintenance and no flue needed, so installation is simpler.
Greener if you’re using renewable electricity, like solar panels or a green tariff.
Watch Out For:
Higher running costs compared to gas boilers, especially in larger homes.
Not ideal for very large properties with high heating demands, as they can struggle.
Your electricity supply might need upgrading to handle the load - check with your installer.
5. Oil Boiler Costs
Oil boilers are a go-to for homes that aren’t connected to the gas grid, often in rural or remote areas. They work similarly to gas boilers but use oil for fuel, which is stored in a tank on your property.
The boiler itself costs £1,000–£3,500, but installation can be pricier due to the need for a fuel tank (which can cost £500–£1,500 if you don’t already have one) and a more complex setup. Total costs, including fitting, typically land around £4,000, but premium models or tricky installations can push it to £5,500.
Key details:
Price Range (with Installation): £2,500–£5,500
Average Cost: £4,000
Best For: Rural homes off the gas grid.
Why Choose an Oil Boiler?
Essential if you’re off the gas grid and can’t use a gas boiler.
Modern oil boilers are more efficient than older models, with some reaching 90%+ efficiency.
It can be paired with renewable tech like solar to reduce your carbon footprint.
Watch Out For:
Oil prices can fluctuate, affecting running costs - check the market before committing.
You’ll need space for an oil tank, which might not suit smaller properties.
Maintenance can be higher than gas boilers, as oil tanks need regular checks.
6. Boiler Conversion Costs
Switching from one boiler type to another can add a chunk to your bill, as it often involves more labour and materials. Here’s what to expect:
Regular to Combi Conversion: Adds £800–£1,200 (total: £2,300–£5,700).
This involves removing the old boiler, cylinder, and tank, then installing the new combi boiler with upgraded pipework.
It’s a popular upgrade because combis are more efficient and save space, but it can take 1–2 days and requires skilled engineers.
The cost includes the removal of old components, new pipework, and upgraded heating controls, plus a chemical flush to clean your system.
Back Boiler to Combi Conversion: Adds a fixed £395 with Heatable (total: £3,500–£5,000).
Back boilers, often hidden behind fireplaces, are outdated and can’t be repaired under modern regulations - they’re like an old dog that needs putting down (sorry, Fido).
Converting to a combi involves removing the old system and rerouting pipework, which can be tricky due to the awkward location.
Heatable’s fixed £395 fee keeps costs transparent, but other companies might charge more to cover the extra hassle - some even price themselves out of the job because they dread the work.
Do note that other, much more expensive quotes are available elsewhere. Try your energy provider if you fancy a laugh.
Please note: Ultimately, an accurate boiler installation cost depends on a variety of factors personal to your situation.
Case Study: Converting a Baxi Bermuda Back Boiler
…But a broken back-boiler is an old dog that needs to be put down.
Imagine you’ve got an old Baxi Bermuda back boiler lurking behind your fireplace. Switching to a combi will cost around £3,500–£5,000 with Heatable, including our £395 conversion fee.
The benefits are worth it: you’ll save on energy bills (potentially £300+ a year), reduce your carbon footprint, get instant hot water, and make your home safer.
Plus, a modern boiler can even boost your property’s value - buyers love efficiency. If the cost feels steep, check out our boiler finance guide for ways to spread the payments, like interest-free options.
Want to have your boiler moved to a different location? Check out our "cost of moving boiler" guide.
If your radiator is cold at the bottom, it's likely a build-up of sludge, but in some cases, it may be a sign of a faulty heat exchanger or a faulty boiler valve, in which case getting your new boiler replaced may be appropriate, check out the Worcester Bosch Greenstar 30i, which you can purchase through us.
Boiler Costs by Brand
Different brands come with different price tags, depending on their reputation, build quality, and guarantee length. Here’s what you’ll pay for some of the UK’s most popular boiler brands in 2025:
Boiler Brand: | Combi Boiler Price Range | System Boiler Price Range | Conventional Boiler Price Range |
£1,500 - £3,500 | £1,200 - £2,600 | £1,200 - £2,600 | |
£1,500 - £3,700 | £1,200 - £2,200 | £1,200 - £2,200 | |
£1,500- £3,500 | £2,000 - £2,500 | £2,000 - £2,500 | |
£1,300 - £2,500 | £1,300 - £2,500 | £1,300 - £2,500 | |
£1,000 - £2,400 | £1,000 - £2,400 | £1,000 - £2,400 | |
£1,300 - £2,500 | £1,300 - £2,500 | £1,300 - £2,500 |
Why Brand Matters:
Worcester Bosch and Viessmann are top-tier, often winning Which? Best Buy awards for reliability and efficiency. They’re pricier but worth it for long-term savings - think of them as the Rolls-Royce of boilers.
Alpha and Baxi offer budget-friendly options without skimping on quality - great if you’re watching the pennies but still want a decent guarantee.
Want more on reliability? Check out our guide to the Most Reliable Combi Boilers in 2025 to see which brands stand the test of time.
Additional Costs to Consider
Here’s a rundown of extras that might sneak into your final bill, along with how Heatable keeps things affordable:
#1 - How much does a new boiler cost?
Probably the most pivotal aspect of any installation – the actual boiler. Boiler replacement costs for quality boilers will be in the high hundreds/early thousands and vary depending on their quality, model, kW size, and brand.
Typical boiler replacement cost:
£600 → £2000
#2 - Boiler installation labour cost
The cost of a boiler installation will depend on the amount of labour required. This can vary based on your location and the business you use, how long it takes to install the boiler and the number of engineers required.
On average, the cost to install a new boiler will be between £600 and £1,500, which depends on the exact type of installation.
For example, a combi swap, taking around a day to complete, is much quicker than a back boiler conversion, which takes around 2 days and may require more than one engineer to attend.
The cost of boiler installation is typically included in the fixed price quote, so if you choose to purchase your boiler via Heatable, you don’t have to worry about juggling different costs and calculating a final figure.
Labour cost (swap):
£600 → £800
Labour cost (conversion):
£1000 → £1500
#3 - Vertical flue cost
A flue is the pipe that carries exhaust gases out of your home. If it needs to exit vertically through the roof (rather than horizontally through a wall), it’s more work - think scaffolding, roof tiles, and extra labour. It’s just bad luck if your home’s layout requires this, but it’s essential for safety.
Typical vertical flue cost:
£300 → £600
#4 - Plume kit cost
A plume kit extends the flue to redirect exhaust gases safely, required by law if the flue is too close to windows, doors, or your neighbour’s garden. It keeps the peace (and ensures you’re Gas Safe compliant). Without it, you’d be breathing in fumes, which is about as fun as a London smog day.
Typical plume kit cost:
£90 → £130
#5 - Main gas pipe upgrade
Older systems often have narrow 15mm gas pipes that need upgrading to 22mm to meet modern regulations. Some homes even have ancient lead pipes, which need replacing with copper. Some companies charge extra for this, but Heatable includes it at no cost - no nasty surprises here.
Heatable never charge for upgraded pipework, whereas most installation companies will add this to your bill with unnerving pleasure and an evil laugh.
Be wary of rogue traders who don’t plan for upgraded pipework – their boiler replacement costs and installation fees will be more illegal than the contents of a duffel bag in the back of their uninsured white van.
Related reading:
Typical gas upgrade cost:
£250 → £400
Our gas upgrade cost:
£0
#6 - Cost to relocate boiler
Moving your boiler to a new spot (e.g., from the kitchen to the garage) requires extra labour, pipework, and fittings. It’s a big job, often taking 2 days, and can involve rerouting pipes through walls or floors. Unless it’s your lifelong dream, try to avoid it - it’s not cheap. See our Cost of Moving a Boiler Guide for more details.
#7 - Smart controls
Smart thermostats let you control your heating from your phone - handy for saving energy and staying cosy. Think Hive, Nest, or tado°. Basic controls are free with Heatable, but premium ones will cost extra. They’re worth it if you love tech and want to cut your bills further.
Heating controls cost:
£100 → £300
#8 - Upgraded warranty costs
Extended warranties, particularly 10-year warranties in most cases, can only able to be offered by trusted partners of manufacturers.
They can sometimes rely upon the fitting of additional approved equipment like magnetic boiler filters and will often incur additional costs to the installer, but a longer warranty is certainly a cost worth incurring.
Think you've found a bargain? Check the warranty length has a longer expiry date than the last lot of milk you bought.
#9 - Magnetic boiler filter cost
A magnetic filter catches debris in your system, like rust or sludge, protecting your new boiler from damage. It’s a must-have to extend your boiler’s life, and we fit them as standard at no extra cost. Without one, you’re risking breakdowns down the line.
Magnetic boiler filter cost:
£100 → £200
Our magnetic filter cost:
£Zero
#10 - Chemical flush
A chemical flush cleans sludge from your system, ensuring your new boiler runs efficiently. If your radiators are cold at the bottom, this is a sign you need one.
We include this for free, unlike some installers who might charge extra. Be wary of “powerflushes” costing £500+ - they can do more harm than good on old systems by forcing high-pressure water through fragile pipes.
Chemical flush cost:
£100 → £150
Heatable's flush cost:
£0 - Free again.
#11 - Radiator Costs
If your radiators are old, rusty, or inefficient, replacing them during the boiler installation can improve performance. Costs depend on size, material (e.g., aluminium vs. steel), and how many you need. A single radiator might cost £100, while a full set for a 3-bedroom house could be £500.
How much will a new boiler save you?
Old boilers are like leaky buckets - money just pours out in wasted energy. Upgrading to a modern A-rated boiler can save you a bundle. According to the Energy Saving Trust, here’s what you could save annually by replacing an old G-rated boiler (less than 70% efficient):
Old Boiler Rating: | Bungalow | Detached House | Flat (Mid-Floor) | Semi-Detached House | Mid Terrace House |
G (<70% efficient) | £345 | £640 | £150 | £385 | £320 |
F (70-74% efficient) | £245 | £460 | £100 | £275 | £225 |
E (74-78% efficient) | £195 | £370 | £80 | £220 | £180 |
D (78-82% efficient) | £150 | £295 | £60 | £170 | £140 |
That’s less money down the drain and more for your holiday fund - or at least a decent cuppa. Plus, a new boiler reduces your carbon footprint, which is a win for the planet (and your conscience).
For every £10 you spend on an old G-rated boiler, up to £4 is wasted - new boilers cut that waste dramatically.
If you’re curious about the greenest options, biomass boilers or electric boilers paired with renewable energy (like solar panels) are worth a look. They’ll save you even more in the long run, especially with rising energy prices.
Grants for New Boilers in 2025
Boilers aren’t cheap, but you might qualify for financial help to ease the burden. Here’s what’s available in 2025:
ECO4 Scheme (2022–2026):
This government scheme aims to improve energy efficiency and reduce fuel poverty across the UK. If you’re on benefits like Universal Credit, Pension Credit, Child Tax Credits, Housing Benefit, or Income Support, you could qualify for a subsidised boiler upgrade.
The ECO4 scheme plans to upgrade nearly half a million UK homes by 2026, focusing on the least energy-efficient properties (think EPC ratings of D or below). It’s designed to make heating more affordable and cut carbon emissions, so you’re helping the planet while saving money.
Boiler Replacement Scheme (Northern Ireland):
Exclusive to Northern Ireland, this scheme offers up to £1,000 towards a new boiler for eligible households. You’ll need to meet specific criteria, such as income level, property type, or energy efficiency rating.
For example, homes with old, inefficient boilers (G-rated or below) are often prioritised. Contact your local authority or the Northern Ireland Housing Executive for details on how to apply.
Boiler Upgrade Scheme (BUS):
This one’s for eco-conscious homeowners switching from fossil fuel systems (like gas or oil) to heat pumps or biomass boilers. Grants include:
£7,500 for air source heat pumps or ground source heat pumps.
£5,000 for biomass boilers.
The BUS has £450 million in funding as part of a £3.9 billion government push to decarbonise heating and buildings, announced in 2025.
Note: this doesn’t apply to gas boilers, but it’s worth considering if you’re exploring greener options like a heat pump for your home. Heat pumps are more expensive upfront (starting at £8,000 including installation), but the grant and lower running costs can make them a smart investment.
Next Steps For Your New Boiler Journey:
When planning to install a new boiler for your home, there are several important factors to consider. Make sure to refer to the following guides to help you make informed decisions:
To dive deeper into these topics, head over to our advice section or check out our YouTube channel to learn more.
Summary - Average New Boiler Costs in the UK
The cost of a new boiler in the UK isn’t a one-size-fits-all figure - it shifts depending on the boiler type and how tricky the installation gets. Here’s the breakdown:
Combi Boilers: Perfect for smaller homes, these range from £1,500 to £4,500 with installation - great value if you’re swapping out an old unit!
System Boilers: Ideal for larger households, expect £1,700 to £5,000, especially if a new hot water cylinder is needed.
Conventional Boilers: Suited for traditional setups, costs span £1,700 to £4,500, depending on your existing system.
Oil Boilers: A must for off-grid homes, prices run from £2,500 to £5,500, factoring in the fuel tank setup.
Electric Boilers: A greener option for gas-free properties, averaging £1,700 to £4,500 - running costs may vary, though!
What drives these costs? It’s not just the boiler itself - think brand prestige (e.g., Worcester Bosch vs. budget options), size to match your home’s needs, labour rates (higher in London, lower in rural areas), and any extras.
Upgrades like relocating your boiler (£500–£1,500), adding smart controls (£100–£300), or fitting a magnetic filter (free with Heatable!) can nudge the total up. A regular-to-combi conversion? That’ll add £800 to £1,200, covering pipework and removal of old tanks.
Get A New Boiler Quote Today
If you’re aiming to get the best deal on a new boiler, consider getting a quote from us. Here’s why:
Gas Safe installation within 24 hours.
Thousands of satisfied customers with an average score of 4.9 on Trustpilot, surpassing the market leader.
Which? Trusted Trader: Heatable is proudly recognised as a Which? Trusted Trader.
Price match guarantee: We will match any like-for-like cheaper quote.
Flexible payment options, including interest-free finance*.
Up to a 12-year guarantee on selected boilers.
Fixed price guarantee: No hidden costs.
Save your quote and decide later.
Get an instant fixed price on a new boiler here.
To learn more about boilers, visit our advice section, check out our YouTube channel, or read customer testimonials here.
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