How much does a new boiler cost in the UK

At iHeat, we’ve installed thousands of boilers nationwide, giving us firsthand insight into the real prices UK homeowners pay, not just the figures often quoted online.

The guide below combines our own 2025 installation data, engineer experience, and customer trends to give a clearer picture of what a new boiler really costs.

How much does a new boiler cost?

The cost of a new boiler in the UK typically starts from around £1,800 and can reach £4,500 or more depending on your property, installation complexity, and chosen brand.

From our 2025 iHeat installations, the average real-world cost for a combi boiler replacement was £2,242. Most homeowners choose mid-range models like the Worcester Bosch 4000 balancing price, performance, and warranty length.

There are a lot of varying factors such as your location, boiler size, system type, property size and much more,

1. Combi boiler cost

New Combi Boiler Average Cost (Installed): £1,800 - £4,500

Advantages: Space-saving, energy efficient, on-demand hot water.

Combi boilers have long since been the most popular type of boiler in the UK (around 80%) due to the fact they conveniently ‘combine’ both a home’s central heating duties and hot water production into one compact, powerful unit.

The price for a new combi installed can range due to many varying factors such as size, complexity and labour, however the average cost sits around £1,800 - £4,500 for a boiler suitable for a 3-4 bedroom home.

Best property match: smaller homes to medium homes, flats, properties with only one shower or bath. 

Example: In May 2025 in Manchester for a 2 bedroom, terraced house with 1 bathroom cost the customer £1,995, this included full installation, removal of old system and new pipework.

2. System boiler cost

New System Boiler Average Cost (Installed): £1,800 - £5,000

Advantages: Powerful, stores hot water, great for larger spaces.

System boilers are perfect for homes with higher hot water demands, such as those with two or more bathrooms. System boilers work with a water cylinder which stores hot water to allow for high pressure service to multiple outlets at the same time.

Converting a system boiler to a combi often adds £300-£600 due to rerouting and removal of hot water cylinders.

Best property match: Larger properties or properties with more than one bathroom.

Example: Another recent installation by iHeat in September in the London area for a 4 bedroom, detached house with 1 bathroom and an en-suite cost the customer £2,695, this included full installation again.

3. Conventional boiler cost

New Conventional Average Boiler Cost (Installed): £1,800 - £5,000

Advantages: Suited to large properties, reliable and consistent.

Conventional (heat-only or regular) boilers are very hardworking and a tad more long standing in terms of their design and function. They do however require an external hot water cylinder and cold water storage tank.

Converting a regular boiler to a combi often adds £300-£600 due to rerouting and removal of hot water cylinders.

Best property match: Big homes with more than one bathroom or lower water pressure.

Example: iHeat completed a regular boiler conversion to a combi-boiler recently for a 3 bedroom semi-detached house, this cost the customer £3,200 for the full conversion, this included everything to be back up and running again within 2 days.

4. Electric boiler cost 

New Electric Boiler Average Cost (Installed): £1,800 - £5,000

Advantages: Very high-efficiency, more environmentally friendly

Electric boilers are a fantastic option for larger homes, especially those without a connection to gas. New electric boilers are not only highly efficient but also considered ‘green’ due to their lack of reliance upon fossil fuels.

Often the cost of an electric boiler may be cheaper than gas due to the fact they do not require a flue or specific pipework. However, it should be noted that electricity is actually more expensive in terms of running costs compared to gas.

Best property match: Properties with no established gas connection, ‘green’ homes.

5. Oil boiler cost

New Oil Boiler Average Cost (Installed): £2,200 - £5,000

Advantages: Great for homes that are rural or off-grid

Oil Boilers are an older type of system, strong but most commonly found in rural properties or homes that do not have an established gas connection.

Best property match: Rural or countryside homes within no gas connection.

It can be important to remember that the cost of a new boiler replacement isn’t only the cost of the appliance itself, but also everything that goes into the process to ensure safety and efficient performance.

From our experience installing thousands of boilers, most UK homes fall between £1,900 and £2,800 once flue upgrades and filters are included.

Boiler costs by brand (boiler only)

The cost of a boiler can vary depending on the brand of the boiler. Some manufactures have outstanding quality of build and remembering the old saying "you get what you pay for".

These prices are based on the boiler only, this does not include installation or removal of your old boiler.

Influencing costs to consider

A quick guide on what common additional costs you may need to account for when it comes to getting a brand new shiny boiler. This includes a typical breakdown in costs of everything needed for a new boiler installation/replacement.

1. The boiler

Of course the main fee for boiler installation is that of the actual new boiler unit itself, without labour. New boilers (just for the boiler unit) can often cost into the early thousands, especially for trusted and award-winning models.

Average boiler unit cost: £600 - £3,600

2.  Installation (engineer labour)

The next most vital fee to consider is the cost of the boiler being installed by a Gas Safe heating engineer.

This exact amount of this fee is usually dependent on several factors unique to each boiler installation, such as:

• Region of the property 

• Complexity of the install

• Boiler type and model

• Number of engineers required

• Added work (system or piping replacements)

Some more straightforward installations such as direct like for like swaps are far quicker and less expensive than old system conversions, for example.

Installation costs are always included in any fixed price iHeat new boiler quote, so you don't have to worry.

Average installation costs: £600 - £1,500

3. Flue cost

The flue is the pipe that transports exhaust gases to outside the home, an essential safety feature. Flues can either be vertical (straight up through the roof) or horizontal (sideways through a wall).

Vertical flues often require more intensive labour to fit correctly, and can therefore provide a higher cost.

Average vertical flue cost: £350 - £550

4. Plume kit cost

A plume kit is a component which extends the flue in order to divert the exit fumes in a safe manner, should the flue be deemed too close to features such as windows or gardens. A tad annoying as an additional cost perhaps, but an essential piece of safety equipment.

Average plume kit cost: £80 - £150

5. Gas pipe upgrade cost

If your home has 15mm pipes they’ll need to be upgraded to roomier, and more efficient 22mm ones.

Here at iHeat, we safely swap out all old 15mm piping to new robust 22mm completely FREE, at no extra cost where applicable.

Average cost: £200 - 800

iHeat gas pipe upgrade cost: FREE

6. Boiler relocation costs

Moving your boiler to a new spot in your home can increase the overall cost, as it’s a more complex job.

The engineer needs to safely relocate the boiler and pipework, making sure everything is reconnected properly so your heating runs just as smoothly as before.

The price very much depends on where your boiler is currently located and where its moving location to, the average cost can range from £400 to £1200+.

Average costs to move a boilers location

7.  Carbon monoxide alarm cost

CO (carbon monoxide) alarms are a specialist bit of kit that alerts a homeowner to potentially life threatening hazardous gas leaks.

With every new boiler installation iHeat offers a FREE CO alarm.

Average cost: £10 - £20

iHeat CO alarm cost: FREE

8. Smart thermostat cost

Helpful technology such as wireless thermostats allow a homeowner to easily control or adjust their property’s central heating or hot water production, all at the click of a button.

with every new boiler installation, iHeat offer a FREE wireless thermostat.

Average cost: £40 - £80

iHeat wireless thermostat cost: FREE

9. Extended warranty cost

A boiler warranty is a little extra peace of mind for a homeowner that should a boiler begin to have issues at no fault of their own, within an appropriate time period, the manufacturer agrees to either fix or replace the unit.

Boiler manufacturers often offer extended warranties highlighting their confidence in their boilers performance and longevity.

10. Magnetic boiler filter cost

Magnetic boiler filters trap pesky debris within the system to keep your boiler in the best possible working condition for the longest amount of time possible.

With every iHeat installation you get a FREE magnetic filter to protect your boiler from sludge and debris.

Average cost: £80 - £120

iHeat magnetic boiler filter cost: FREE

11. Chemical flush cost

Chemical flushes are a system cleaning procedure that will remove any unwanted bits and bobs to allow your new boiler to run as best it can.

Chemical flushes are offered as part of every new boiler installation for FREE with iHeat.

Average cost: £20 - £60

iHeat chemical flush cost: FREE

12. Replacement radiator cost

Even after installing a brand new boiler, if your property's radiators are useless, your home still won’t be as toasty as you desire. If this is the case it’s worth replacing the older radiators with new and heat efficient ones.

Average radiator cost (per radiator): £200 - £400

Estimated costs by property type

The total cost of a new boiler installation also depends on the size and layout of your home.

Larger homes or more complex properties tend to incur higher labour and material costs.

The table below gives indicative ranges for common UK property types based on typical installations and our experience.

Ranges are based on typical installations. Final cost will depend on boiler type, fuel type, system condition, pipe-work, location, and any required upgrades.

Government grants and funding available in 2025

The UK government supports eligible households with heating upgrades under the ECO4 Scheme (Energy Company Obligation). While it is not a general boiler replacement grant, it can cover part or all of a new boiler installation if you meet the criteria.

What the scheme covers

• Homes with an EPC rating of D, E, F or G. 

• Households classed as fuel-poor or receiving certain qualifying benefits (eg Universal Credit, Pension Credit, Housing Benefit) and with an inefficient heating system. 

• Measures can include boiler replacement/upgrades, heating controls, insulation or first-time central heating. 

Key points to know

• The scheme is available until 31 March 2026 for installations from 1 April 2022 onwards. 

• You cannot simply apply yourself: an approved installer carries out the assessment and submits the application. 

• The amount of support varies and you may still have to cover part of the cost, a full free replacement is not guaranteed.

If your property qualifies, you could reduce the upfront cost of a new boiler by a significant margin. But if you do not meet the criteria (good EPC rating, no qualifying benefit, etc), you will need to budget the full cost yourself, so factoring in this possibility is wise.

Please note: eligibility depends on your personal and property circumstances. Always check your property’s EPC rating and speak with a Gas Safe installer to confirm whether you qualify for ECO4 funding.

How much money could a new boiler save me?

Over the years, we’ve noticed that customers who book during spring or summer often save up to 10% compared with peak winter installs. Installers have more availability, and prices tend to be lower, a small but useful tip based on our own scheduling trends.

Modern gas boilers are far more energy efficient than older models, meaning by installing a new boiler, you would actually start to save money long term due to the reduced energy bill costs.

At iHeat, we encourage customers to weigh efficiency and warranty length over the lowest upfront quote. A boiler that’s 5% more efficient can save hundreds over its lifetime.

How much will you save with an A-rated boiler, you ask? Well, here’s a quick breakdown:

These figures are estimates based on replacing an older boiler with a new A-rated condensing model, including a programmer, room thermostat, and thermostatic radiator valves (TRVs), in a gas-heated home.

Data from https://energysavingtrust.org.uk/advice/boilers/ - Figures are based on fuel prices as of July 2025,

New boiler cost summary

The average new boiler cost in the UK can vary depending on the type of new boiler and the complexity of the installation.

• Combi Boilers - efficient and space-saving, combi boilers are the UK’s most popular boiler with an average cost of £1,800 - £3,500.

• System Boilers - powerful and suited to large properties, new system boilers have an average cost of £1,800 - £5,000.

• Conventional Boilers - reliable and straightforward, ‘heat-only’ boilers have an average cost of £1,800 - £5,000.

• Electric Boilers - environmentally friendly and very efficient, these boilers have an average cost of £1,800 - £5,500.

• Oil Boilers - traditional and robust, oil boilers have an average cost of £2,200 - £5,000.

• Biomass Boilers - the greenest option for eco friendly homes, these boilers have an average cost of £9,000 - £15,000.

Many homeowners fixate on boiler price alone, but our data shows extras like moving the boiler location, TRV's and smart thermostats make up 10-15% of total cost. Ignoring them can lead to unrealistic budget expectations.

Quick Insights

• Average combi replacement: £2,242 (2025)

• 52% of homeowners choose 0% APR finance

• 25% add smart thermostats at installation

• Most popular model: Worcester Bosch 4000

Expert boiler quotes and installation with iHeat

At iHeat, we believe in transparency. Our prices are based on real installation costs from an iHeat qualified Gas Safe engineers, not estimates.

Here’s why thousands of UK homeowners choose iHeat:

• Gas Safe engineers install every boiler safely and professionally.

• Fixed prices online, no hidden extras, ever.

• Which? Trusted Trader accredited for consistent high standards.

• Flexible finance options including 0% APR.

• Up to 12-year manufacturer warranties on selected boilers.

• Thousands of 5 star verified reviews from happy customers.

• Bolton News Customer Service company of the year 2024

Get your instant fixed-price quote today and see how much you could save.

Get a quote

References
Energy saving trust - https://energysavingtrust.org.uk/advice/boilers/
Boiler upgrade scheme - https://www.gov.uk/apply-boiler-upgrade-scheme

*Information based on the 6,409 boiler installations completed by iHeat this year (as of October 2025) across the entire UK. Please note: all cost ranges are indicative and based on typical installations. Final cost will depend on your property, boiler type, fuel source, location, system condition and inclusion of any upgrades. An online quote is required for an accurate price.