How much does a new boiler cost in the UK

If you're wondering about the cost of a new boiler, most UK homeowners can expect to pay between £1,800 and £4,500 for a new boiler and installation.

The final price depends on factors such as the type of boiler you choose, your property's heating system and whether any additional work is needed during installation.

From our experience installing thousands of boilers across the UK, straightforward like for like replacements are often at the lower end of the price range.

More complex installations, such as changing boiler type, relocating the boiler or upgrading pipework, can increase the overall cost.

If your current boiler has stopped working, our boiler troubleshooting guide can help identify common faults before deciding whether a replacement is necessary.

This guide explains new boiler costs by boiler type, brand and property size, along with the installation factors that influence the final price, helping you understand what to expect before requesting a quote.

How much does a new boiler cost?

The cost of a new boiler in the UK typically ranges from £1,800 to £4,500, including installation.

The amount you pay will depend on factors such as the type of boiler you choose, your property's existing heating system, the complexity of the installation and whether any additional work is required.

Based on more than 7,000 iHeat installations completed over the past 12 months, the average cost of a straightforward combi boiler replacement was £2,242.

Many homeowners choose mid-range models such as the Worcester Bosch 4000, which offer a good balance of performance, efficiency and manufacturer warranty.

For comparison, the Energy Saving Trust estimates that replacing a gas boiler in Great Britain typically costs around £3,700, while oil boiler replacements in Northern Ireland average around £3,200, depending on the property's heating system and installation requirements.

Below, you'll find typical installation costs for each boiler type, along with the advantages, best property types and real installation examples to help you compare your options.

1. Combi boiler cost

New combi boiler average cost (installed): £1,800 to £4,500

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

Combi boilers are the most popular type of boiler in the UK because they provide both central heating and hot water from a single compact unit.

They don't require a separate hot water cylinder or cold water storage tank, making them an excellent choice for homes where space is limited.

From our experience, a straightforward like for like combi boiler replacement is often the most cost-effective type of installation.

However, the final price will depend on factors such as the boiler's output, the complexity of the installation and whether upgrades to your existing heating system are needed.

For most homes, you can expect to pay between £1,800 and £4,500 for a fully installed combi boiler, including labour. Higher specification models and more complex installations are usually towards the upper end of this range.

Best suited for: Flats, bungalows and small to medium-sized homes with one bathroom and a typical daily demand for hot water.

Example: A recent iHeat installation in Manchester for a two-bedroom terraced house with one bathroom cost £1,995, including the new combi boiler, full installation, removal of the old boiler and new pipework where required.

If you're still deciding which model is right for your home, read our best combi boilers for 2026 guide for an in-depth comparison of the leading options.

2. System boiler cost

New system boiler average cost (installed): £1,800 to £5,000

Advantages: Excellent hot water performance, ideal for higher demand households and compatible with modern unvented cylinders.

System boilers store hot water in a separate cylinder, making them well suited to larger homes where multiple taps or showers are likely to be used at the same time. Unlike conventional boilers, they don't require a cold water storage tank in the loft, helping to simplify the overall system.

From our experience, system boilers are often the preferred choice for households with two or more bathrooms where a combi boiler may struggle to meet peak hot water demand. If you're replacing an existing system boiler with a similar model, installation is often more straightforward than converting from another boiler type.

For most homes, you can expect to pay between £1,800 and £5,000 for a fully installed system boiler. If you're converting from a regular boiler or changing to a combi boiler, additional work such as removing the hot water cylinder or altering pipework can increase installation costs.

Best suited for: Medium to large homes with two or more bathrooms and a higher demand for hot water.

Example: A recent iHeat installation in London involved replacing a system boiler in a four-bedroom detached home with one main bathroom and an en-suite. The total cost was £2,695, including the new boiler and full installation.

3. Conventional boiler cost

New conventional boiler average cost (installed): £1,800 to £5,000

Advantages: Reliable, well suited to high hot water demand and compatible with traditional heating systems.

Conventional boilers, also known as regular or heat-only boilers, work alongside a separate hot water cylinder and cold water storage tank.

They remain a practical option for larger homes, particularly those with older heating systems or higher hot water demand.

From our experience, replacing an existing conventional boiler with a similar model is often the most straightforward option for properties already designed around this type of heating system.

However, converting to or from a conventional boiler usually requires additional pipework and system alterations, which can increase installation costs.

For most homes, you can expect to pay between £1,800 and £5,000 for a fully installed conventional boiler, depending on the boiler you choose and the complexity of the installation.

Best suited for: Larger homes with multiple bathrooms, traditional heating systems or properties with lower mains water pressure.

Example: iHeat recently completed a conventional boiler to combi boiler conversion for a three-bedroom semi-detached home.

The total installation cost was £3,200, including the new boiler, removal of the existing system and all associated conversion work, with the new heating system fully operational within two days.

4. Electric boiler cost 

New electric boiler average cost (installed): £1,800 to £5,000

Advantages: Highly efficient at the point of use, compact, quiet and doesn't require a gas supply or flue.

Electric boilers heat water using electricity rather than burning gas or oil, making them a practical option for homes without access to the gas network. They're generally smaller than gas boilers and can often be installed where space is limited.

From our experience, electric boilers are most suitable for smaller homes, flats and well insulated properties with lower heating and hot water demand.

While installation can sometimes be simpler because there's no flue or gas pipework, electricity is typically more expensive than mains gas, so ongoing running costs should also be considered.

For most homes, you can expect to pay between £1,800 and £5,000 for a fully installed electric boiler. The final cost will depend on the boiler output, your property's electrical system and whether any upgrades are required before installation.

Best suited for: Flats, smaller homes, properties without a mains gas connection and well insulated homes with lower heating demands.

5. Oil boiler cost

New oil boiler average cost (installed): £2,200 to £5,000

Advantages: Reliable for off-grid homes, high heat output and suitable for properties without access to mains gas.

Oil boilers are commonly installed in rural properties where a mains gas connection isn't available. They operate in a similar way to gas boilers but require an external oil storage tank, which supplies fuel to the heating system.

From our experience, replacing an existing oil boiler is usually more straightforward than converting from another heating system. However, installation costs can vary depending on the condition of the existing oil tank, pipework and flue, as well as whether any upgrades are required to meet current safety standards.

For most homes, you can expect to pay between £2,200 and £5,000 for a fully installed oil boiler. The final cost will depend on the boiler you choose, the complexity of the installation and any additional work required.

Best suited for: Rural properties, off-grid homes and any property without access to the mains gas network.

Boiler costs by brand (boiler only)

Boiler prices vary between manufacturers due to differences in build quality, features, warranty length and output options.

While premium brands generally cost more upfront, they often include longer warranties and additional features. Based on iHeat installations over the last 12 months, the average real-world cost for a combi boiler replacement was £2,242.

For a more in-depth look, check out our 2026 guide on the best boiler brands!

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. Boiler

The boiler itself is usually the largest single cost within a new boiler installation, although it only forms part of the total price.

The amount you pay depends on the manufacturer, model, output and warranty, with premium boilers typically offering longer warranties and additional features.

From our experience, many homeowners choose a mid-range boiler that provides a good balance between upfront cost, efficiency and long-term reliability.

Selecting the right boiler size for your home's heating and hot water demand is just as important as choosing the brand, as an oversized or undersized boiler can affect both performance and running costs.

Average boiler unit cost: £600 to £3,6002.  Installation (engineer labour)

2. Installation

Installation costs cover far more than fitting the new boiler.

A Gas Safe engineer will safely remove the existing boiler, install the new appliance, carry out all necessary pipework, commission the system and complete the required safety checks before the installation is signed off.

From our experience, straightforward like for like boiler replacements are generally quicker and less expensive than installations involving a boiler relocation, system conversion or heating system upgrades.

Every property is different, which is why labour costs can vary depending on factors such as:

• The complexity of the installation.

• The type of boiler being installed.

• The property's existing heating system.

• Any additional pipework or system upgrades required.

• The location of the boiler within the property.

With iHeat, installation costs are included within your fixed online quote, so you'll know exactly what's included before any work begins.

Average installation cost: £600 to £1,500

3. Flue cost

The flue safely removes waste gases from your boiler to the outside of your property and is an essential part of every gas boiler installation.

Depending on your home's layout, the flue may exit through an external wall (horizontal) or through the roof (vertical).

From our experience, most standard boiler replacements can use a horizontal flue.

However, some properties require a vertical flue, which generally involves more labour and materials, increasing the overall installation cost.

Average vertical flue cost: £350 to £550

4. Plume kit cost

A plume kit extends the flue terminal so that water vapour is discharged in a safe location away from nearby windows, doors, neighbouring properties or public pathways.

Not every installation requires one, but where clearances don't meet current regulations, it can be an essential part of the installation.

From our experience, plume kits are only fitted when needed to comply with installation standards and ensure the boiler operates safely.

Average plume kit cost: £80 to £150

5. Gas pipe upgrade cost

If your existing gas supply pipe isn't large enough to meet the boiler manufacturer's requirements, it may need to be upgraded during installation. Modern boilers often require a larger gas supply to operate safely and efficiently.

From our experience, upgrading older 15mm gas pipework to 22mm is a common part of many boiler replacements. Where required, iHeat carries out this upgrade at no additional cost as part of the installation.

Average cost: £200 to £800

iHeat gas pipe upgrade cost: FREE

6. Boiler relocation costs

Moving your boiler to a different location can make better use of space or improve access, but it also increases the amount of work involved. Pipework, flue routes, condensate drainage and electrical connections may all need to be altered to suit the new position.

From our experience, relocating a boiler within the same room is usually less complex than moving it to another floor or a different part of the property. The final cost depends on the distance involved and the amount of additional work required.

7. Carbon monoxide alarm cost

A carbon monoxide (CO) alarm helps detect dangerous carbon monoxide gas within your home and is an important safety measure for any property with a fuel-burning appliance.

While a new alarm isn't always legally required during every boiler replacement, fitting one is strongly recommended if one isn't already installed in a suitable location.

Every iHeat boiler installation includes a FREE carbon monoxide alarm, giving you added peace of mind from day one.

Average cost: £10 to £20

iHeat carbon monoxide alarm cost: FREE

8. Smart thermostat cost

A smart thermostat gives you greater control over your heating, allowing you to adjust temperatures, create schedules and, in many cases, control your heating remotely using a smartphone.

From our experience, upgrading your heating controls can improve convenience and help many homeowners use their heating more efficiently, particularly when replacing an older boiler.

Every iHeat boiler installation includes a FREE wireless thermostat.

Average cost: £40 to £80

iHeat wireless thermostat cost: FREE

9. Extended warranty cost

Most new boilers include a manufacturer's warranty, although the length of cover varies between brands and models.

Boilers with longer warranties often have a higher purchase price, but they can provide valuable long-term protection against manufacturing defects.

From our experience, many homeowners place as much importance on warranty length as the upfront cost when choosing a new boiler, particularly if they plan to stay in their property for several years.10. Magnetic boiler filter cost

10. Magnetic boiler filter cost

A magnetic boiler filter captures sludge, rust and other debris circulating through your central heating system before it can reach the boiler.

This helps protect key components and supports long-term efficiency and reliability.

Every iHeat installation includes a FREE magnetic boiler filter to help protect your new boiler from system contamination.

Average cost: £80 to £120

iHeat magnetic boiler filter cost: FREE

11. Chemical flush cost

A chemical flush cleans the central heating system before the new boiler is commissioned, helping to remove sludge, corrosion deposits and other contaminants that could affect performance.

From our experience, carrying out a system clean before a new boiler is installed helps give the new appliance the best possible start and supports reliable operation over the long term.

Every iHeat installation includes a FREE chemical flush.

Average cost: £20 to £60

iHeat chemical flush cost: FREE

12. Replacement radiator cost

Installing a new boiler won't automatically improve the performance of older radiators. If your existing radiators are heavily corroded, undersized or no longer heating efficiently, replacing them at the same time can help your new heating system perform at its best.

From our experience, not every boiler installation requires new radiators.

However, replacing worn or inefficient radiators during the installation can improve heat distribution and help you get the most from your new boiler.

Average radiator replacement cost (per radiator): £200 to £400

Estimated costs by property type

The size and layout of your home are two of the biggest factors affecting the cost of a new boiler.

Larger properties generally require higher output boilers and may have more radiators, bathrooms or longer pipe runs, all of which can influence the final installation cost.

From our experience, choosing the right boiler for your property's heating and hot water demand is more important than simply choosing the largest model available.

A correctly sized boiler can improve efficiency, provide more reliable heating and help reduce unnecessary energy use over time.

The guide below shows typical installed boiler costs based on common UK property types.

Actual prices will vary depending on the boiler you choose, the complexity of the installation and any additional work required.

Why do larger homes cost more?

While floor space plays a role, the number of bathrooms, radiators and occupants can have an even bigger impact on boiler selection.

Homes with higher hot water demand often require larger boilers or different heating system configurations, which can increase both equipment and installation costs.

If you're unsure which boiler is right for your home, a personalised quote based on your property's heating and hot water requirements will provide the most accurate price.

While most homeowners spend between £1,800 and £4,500 on a new boiler and installation, larger detached homes or properties requiring a system conversion, boiler relocation or significant pipework upgrades can exceed this range.

This is reflected in the table above, which shows typical costs for more complex installations.

Government schemes, grants and funding available in 2026

Replacing a boiler can be a significant investment, but some households may be able to reduce the upfront cost through government-backed energy efficiency schemes.

Eligibility depends on factors such as your income, benefits received, property type and the existing heating system in your home. Because funding criteria can change, it's always worth checking the latest guidance before making a decision.

One of the main schemes available in England and Wales is the Warm Homes Plan, which supports eligible households with energy efficiency improvements. Depending on your circumstances, this may include help with upgrading your heating system alongside insulation and other measures.

If you're replacing an older, inefficient boiler, it's also worth checking whether your local authority or energy supplier offers any additional support or funding in your area.

Even if you don't qualify for a grant, choosing a modern A-rated boiler can reduce energy use compared with an older, less efficient model, helping to lower heating bills over time.

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

• Most homeowners can expect to pay between £1,800 and £4,500 for a new boiler with installation, although the final cost depends on the boiler type, your property and the complexity of the work.

• The cheapest quote isn't always the best value. Boiler quality, warranty length, installation standards and what's included in the price all contribute to the overall cost.

• A correctly sized boiler is just as important as choosing the right brand. Selecting a boiler that matches your home's heating and hot water demand can improve efficiency, comfort and long-term performance.

• Installation costs vary depending on the work involved. Factors such as boiler relocation, flue requirements, gas pipe upgrades and heating system improvements can all influence the final price.

• Some households may be eligible for government support, so it's worth checking the latest funding schemes before replacing an older heating system.

• Getting a fixed quote based on your property is the most accurate way to understand the total cost, as every installation is different.

If your property qualifies, government funding could reduce the upfront cost of replacing an older, inefficient boiler. If you don't meet the eligibility criteria, you'll need to budget for the full installation cost or consider spreading the cost with boiler finance.

Eligibility depends on your household circumstances, property and existing heating system. Always check the latest government guidance before applying for any funding.

How much money could a new boiler save me?

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.

From our experience, customers who replace their boiler during spring or summer can often benefit from greater installer availability, and installation costs may be lower than during the peak winter period.

Data is based on Energy Saving Trust boiler guidance and their published savings estimates. https://energysavingtrust.org.uk/advice/boilers/

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 - compact, quiet and ideal for homes without access to mains gas, these boilers have an average cost of £1,800 - £5,000.

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

• Biomass Boilers - a renewable heating option for suitable off-gas-grid 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, TRVs 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

• Most popular model: Worcester Bosch 4000

Expert boiler quotes and installation with iHeat

The best way to find out how much a new boiler will cost is with a quote based on your home's heating system and hot water requirements.

At iHeat, every fixed online quote is tailored to your property, so you'll know exactly what's included before deciding to go ahead.

Every boiler is installed by a Gas Safe registered engineer, with transparent pricing, trusted manufacturer warranties and no hidden extras.

From choosing the right boiler to professional installation, iHeat makes replacing your boiler straightforward from start to finish.

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 7000+ boiler installations completed by iHeat last year 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.