How Much Does a New Boiler Cost in 2026?

What Is the Cost of a New Boiler in 2026?

The following table compares the installed cost of three 24-kW combination boilers designed to run with gas, oil and biomass. The comparison also includes a 15-kW electric system boiler:

Boiler Type	Typical Price Range
15 kW Electric System Boiler (210 L)	£1,500 – £2,500
24 kW Gas Combi Boiler	£1,700 – £2,700
24 kW Oil Combi Boiler	£1,500 – £3,500
24 kW Biomass Combi Boiler	£7,000 – £20,000

NOTE: These are estimated cost ranges based on industry data, not actual quotes.

As you can see in the table, there is some overlap between the cost range of electric, gas and oil boilers. However, biomass boilers are significantly more expensive.

Assuming you compare boilers that use the same fuel, prices also vary depending on the type of boiler. Here we compare the typical prices of 24-kW gas boilers from Worcester Bosch, a leading brand in the UK. These prices include installation costs:

• Conventional Boiler = £1,700 – £2,300
• System Boiler = £1,900 – £2,400
• Combi Boiler = £1,800 – £2,600

The price of a boiler also increases along with installed capacity. The following table shows the typical boiler capacity required based on home size, and how much you can expect to pay.

Boiler Size	Number of Radiators	Home Size	Typical Equipment Cost
10-20 kW	1-5	1-2 bedrooms	£800 – £1,000
24-25 kW	5-10	2-3 bedrooms	£900 – £1,300
28-30 kW	10-15	3-4 bedrooms	£1,000 – £1,600
33-35 kW	15-20	4-8 bedrooms	£1,300 – £2,300
40-45 kW	20 or more	8 or more bedrooms	£1,700 – £3,500

Some boiler replacements require additional work such as new fittings or new radiator valves. Here are some typical prices you can expect for complementary installations:

Other Heating System Components	Typical Costs
Replacement fittings	£300 or more
Radiator valves	£100 – £200 per valve, on average
Smart thermostat	£200
Magnetic filters	£75 – £150 per filter

As you can see, the prices of new boilers can vary widely depending on equipment features. Your budget can also increase if the project involves additional tasks such as the following:

• Switching to another fuel: Upgrading to a new boiler that uses a different fuel is more expensive, but you can achieve lower costs in the long run. For example, you can expect lower heating costs if you switch from an oil boiler to a gas boiler.
• Installing the new boiler in a different location: If you decide to install the new boiler in a different location, you also need to relocate piping and fixtures. This also increases the cost of your project. A boiler relocation can add around £500 to your budget.
• Replacing old piping and radiators: In many cases, your new boiler can use the existing piping and radiators. However, if these components are worn out or no longer compliant with building standards, you must also replace them. Complex boiler replacements can have labour costs of over £2,500, in addition to the equipment costs.

Regardless of the type of boiler installed and its energy source, you will achieve best results if the unit is optimally sized for the energy needs of your home. An oversized boiler is not recommended, since you would be spending additional money on heating capacity that is not used. On the other hand, an undersized boiler will be unable to provide enough space heating and hot water for your home.

Payback Period of a New High-Efficiency Boiler

The payback period of a boiler depends on several factors, including the upfront cost of the new unit and the efficiency improvement with respect to the older unit. As a quick example, assume you have a 60% efficient gas boiler that is currently using 15,000 kWh per year, and you plan to install a new boiler with 90% efficiency for £2,500.

• At 60% efficiency, 15,000 kWh of gas input becomes 9,000 kWh of heating output.
• At 90% efficiency, you only need an input of 10,000 kWh to achieve the same output.
• The boiler upgrade in this example saves 5,000 kWh of gas per year.

As of October 2023, Ofgem has established a gas price cap of 7 pence/kWh and 30 pence/day. If you save 5,000 kWh per year at this price, your gas bills are reduced by £350. In this case, the new boiler achieves a payback period of 7.1 years.

The actual payback period of an energy efficient boiler can be much shorter, given that UK gas prices are on the rise. Between the financial years 2021/22 and 2022/23, the annual gas bill for a home using 13,600 kWh increased from £658 to £1,357. In other words, gas prices doubled within a single year.

Note that the payback period varies depending on the efficiency of the boiler being upgraded. The following table provides the estimated savings for several scenarios, considering the same example of a new boiler with 90% efficiency and a cost of £2,500.

Old Boiler Efficiency	Estimated Annual Savings	Payback Period
50%	£560	4.5 years
55%	£445	5.6 years
60%	£350	7.1 years
65%	£269	9.3 years
70%	£200	12.5 years

NOTE: This is just an example. A professional boiler installer can estimate the actual savings you can expect in your house.

As you can see, the business case for installing a new boiler is much better if you are replacing an old and inefficient unit. The potential savings are lower if the efficiency gab between both units is small.

Buying a New Boiler: Importance of a Solid Warranty

Ideally, you should look for a new boiler with solid warranty coverage. A solid warranty makes sure you recover the upfront cost of a new boiler in the form of energy savings. For example, if your boiler has a payback period of 6 years and you get a 10-year warranty, your return on investment is guaranteed.

The following are some leading boiler brands in the UK, who typically offer a 3-10 year warranty:

Brand	Typical Equipment Cost	Typical Warranty
Worcester Bosch	£900 – £2,300	6-12 Years
Vaillant	£900 – £2,700	5-10 Years
Baxi	£700 – £1,300	5-10 Years
Intergas	£600 – £1,500	3-10 Years
Potterton	£600 – £2,000	2-7 Years
Ideal	£700 – £2,800	2-10 Years
Viessmann	£900 – £3,500	3-12 Years
Vokera	£450 – £1,100	2-10 Years

Keep in mind that installation costs can add over £1,000 to your budget. Purchasing boilers directly from manufacturers is possible, but only Gas Safe Certified professionals can install a boiler – DIY installations by unqualified persons are illegal in the UK.You can get a better price by purchasing a fully installed boiler, instead of purchasing the equipment directly and looking for an installer.

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Boiler Energy Efficiency

Energy efficiency will greatly increase the cost of your boiler, but it can often off in the long-term through reduced energy costs. In most cases, you will purchase your boiler based on the A-G rating. Boilers are rated from G (worst energy efficiency) to A+++ (best energy efficiency).

Energy efficiency is important for you because higher energy efficiency means that you waste less energy, because you turn more of it into heat. This lowers your energy bill, means that you get more heat for less money, and reduces your carbon footprint.

As of 2010, the ERP mandates that all boilers must have a minimum energy rating of A, meaning that they are at least 88% efficient. This means that if you purchase a 100,000 BTU boiler, you put 100,000 BTUs of energy in to get 88,000 BTUs of heat out.

These estimates are for a 24-kW combi condensation boiler, replacing an old boiler with an energy efficiency of 60%.

Rating	Average Cost	Annual Energy Savings
A	£565 +	£122
A+	£655 +	£158
A++	£850+	£201
A+++	£990+	£237-350

Importantly, if you own a large home or an older and less efficient boiler, your energy savings could be considerably more.

Non-Condensing vs Condensing – Condensing boilers are up to 25% more efficient than non-condensing boilers, so most options on the market today are condensing boilers. In fact, the most common boiler sold in the UK is a condensing combi boiler, which provides high efficiency, does not require a lot of storage, and are safer. The average person who replaces an old non-condensing boiler (typically rated at 45-65% efficiency) with a new condensing boiler saves £310 per year on their heating bill according to the Energy Saving Trust.

Brand – Most people prefer to purchase good quality brands with long warranties and national respect. This is a good way to ensure that your boiler will last as long as-is possible. However, most nationally known brands are more expensive than budget brands, which is something to keep in mind and to consider.

Brand	Average Cost	Average Warranty
Worcester Bosch	£800-1150	5 Year
Valiant	£800-900	5-10 Year
Baxi	£700-900	3-10 Year
Intergas	£900-1,300	5-10 Year
Potterton	£700-800	7 Year
Ideal	£626-1000	7 Years
Viessmann	£1020-4,500	3-5 Years
Vokera	£579-759	5 Year

It’s important to balance a good brand and a good warranty with cost effectiveness, as you still want your boiler to pay itself off.

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Types of Boiler

Different types of boilers cost more or less money, because the system is smaller or includes more components.

Conventional – A regular boiler features a cylinder and a tank, allowing you to heat and store water. This option is less energy efficient, but allows you to get hot water in multiple places at once, and takes longer to run out of hot water than the system boiler.

System Boiler – System boilers or sealed systems feature a water cylinder but no tank. They are small, easy to fit into a cupboard, and can provide heat to more than one place at once. However, they take some time to heat water

Combination Boiler – Combination boilers are easy and fast to install, require less space, and do not require a tank or a cylinder. Instead, they heat water on demand by passing it over a heating flue.

Back Boiler – Back boilers sit behind the recesses of a fireplace or furnace and therefore save space. However, they can be more expensive to install and to have removed.

Estimates based on a Worcester Bosch 24 kW boiler installation.

Type	Cost
Conventional	£767.39
System	£930.08
Combi	£851.9
Back	£837.86

What Affects Installation Costs?

Installation costs are charged on top of boiler costs, and can be the same or more than the boiler. The simpler your installation, the more affordable it is to replace your boiler.

However, if you have a large house, a very old system, or are making significant upgrades or replacements in the system, your boiler installation costs can be considerable. Here, your best option is to simplify the installation as much as-is possible and shop around to find a good rate for the installation.

Different types of boilers cost more or less to purchase, but they also cost more to install.  For example, installing a regular boiler in the same place as your old one may be very simple, but it might also be very complex.

Importantly, you typically need an inspection to determine exact installation costs, because they will change depending on your home, the condition of your existing system and fittings, and other details. In most cases, boiler installation costs will start at around £600 and will go up to over £2,500 depending on the depth and complexity of the installation.

The following estimates include the cost of the boiler plus the cost of the installation.

Boiler Type	Same Location	New Location
Conventional	£1,750	£2,050
System	£1,350	£1,850
Combi	£1,995	£2,550
Back	£2,000 +	£2,900 +

Moving your boiler to a new location costs more because of the additional work with fitting.

Gas pressure – If you are using a natural gas or oil system, you may have to pay to have gas-pressure adjusted to meet your new system’s needs. This will cost from £50.

Building standards – If your current system is 20 years or older, it may not comply with new building standards. This may mean new piping, new flues, and flue diverters, depending on your system.

Flushing – If your home is very old, your system may need a mechanical flush. This will cost around £510 for the average system, but this cost will vary depending on the size and age of your home. You may also have to have your radiators flushed as well, which will cost more.

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Upgrading Your Systems

Upgrading your system is optional, but it will help you to save money and it can help you to get more from your total system.

Replacement fittings – Replacement fittings and pipe work can cost £300 or more depending on the size of your home.

Radiator Valves – £7-£100 each + labour (typically £60+ each) for an average of £100 per.

Changing Controls/Thermostat – A new thermostat or controls can save you money and give you greater control over your system, but will be costly. Expect to pay from £100 for new radiator valves (per) and around £200 for a good quality thermostat.

Filter – Magnetic filters cost between £75-150

Online quotes aren’t 100% accurate

It’s important to keep in mind that no online quote will be 100% accurate. A contractor can estimate how much a project will cost, but because more than half of the costs of installing a new boiler are based on installation, you need a home inspection to get a good quote.

For example, if you need home upgrades, your existing system does not meet building regulation, you have an underground fuel tank you would like removed, or other complexities, costs will go up a great deal.

Therefore, any online quote is a ballpark figure, not intended as a final quote.

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What to Keep In Mind When Buying a New Boiler?

Purchasing a new boiler can save you money, but it’s important that you get a great boiler and a great deal. By looking out for potential pitfalls, you can avoid issues and make a purchase that represents a great investment.

1. Energy Efficiency

   Know what you’re getting, how much it will save you, and what you’re replacing. If you’re upgrading an 80% efficiency boiler with a 90%, you might not be saving enough to make the upgrade worthwhile.

2. Fuel

   Do your research and make sure you understand costs and pros and cons of your different fuel options.

3. Pipes and Ductwork

   Inspect your pipes and ductwork yourself, and try to find out how old they are. Unless your system is over 15 years old, there’s likely no need to have it replaced. This applies to radiators and fittings as well, because while newer radiators will save you money, they won’t likely pay for themselves unless they’re over 15 years old.

4. Pressure tactics

   Many sales representatives will try to pressure you into closing a deal same-day, and this is never a good idea. Take your time, do more research, and compare your options.

5. Compare your options

   The best way to get a good price on a boiler and installation is to shop around and compare your options. It’s important to compare brands and models, but you should also compare installers. Try to get quotes from at least 3 different installers, and compare what they offer, any extra costs, and their installation warranty. In most cases, you can get a better deal by choosing smaller, local contractors, who pay less in tax and can therefore afford lower installation costs.

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Can I Save Money With a New Boiler?

While the most common reason to upgrade to a new boiler is that your old boiler is broken down, many people also choose to install a new boiler because they want to save money. It’s important to keep in mind that upgrading to a new boiler may or may not save you money depending on the age and energy efficiency of your old system.

These estimates are based on installing a new A-rated gas combi boiler with an energy efficiency of 90%, with a total cost of £2,300.

Old Boiler	Energy Savings	Cost Savings	Time to Break – Even
45%	50%	£560	4.1 years
50%	40%	£350	6.5 years
60%	33%	£237	9.7 years
65%	28%	£201	11.4 years
70%	22%	£158	14.5 years

While your boiler contributes to as much as 55% of your total heating costs, it’s important to remember that your home contributes the other 45%. If you want to save money on heating:

• Make sure your home is insulated and draught proofed
• Ensure you have sealed windows with double or triple glazing
• Check your heating controls (thermostat radiator valves, thermostat, and radiators to ensure you aren’t paying more for your heating)

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Should I Replace My Old Boiler?

In most cases, you should replace your old boiler if it is 15 years old or older, has a rating of less than 70% efficiency, or is costing you significantly in repairs. Most boilers have an average lifespan of 15 years, but a well-cared for boiler can last for 40 or more. However, if you have an old G-rated boiler, you could be losing as much as 50% of the energy you put into it. If your boiler is newer, is not costing you significantly in repair costs, and has a high energy rating, it may not be cost-effective to replace your boiler.

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Choosing a Boiler Installer

While most of us lean towards choosing large national suppliers, they can cost as much as 33% more per installation. For example, British Gas is one of the most expensive places to get a boiler and most homeowners pay an average of £2,500-4,200 for a boiler through their system. This is high in comparison to the average of £1,500-£2,300 that you will get elsewhere.

Your installer should be:

• Gas Safe Certified
• 5-Star Rated
• HSE Compliant

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How Long Does It Take To Install a New Boiler?

Installing a new boiler will typically take 1-2 weeks from start to finish, but may take longer depending on the complexity of the job.

Initial inspection for pricing and quote	1-2 hours
Removing old boiler	1-5 hours
Inspecting piping and gas or oil	1-2 hours
Piping, re-wiring, re-fitting	2-24 hours
System upgrades	varies
Replacing ductwork	1-12 hours
Removing old fuel tanks	1-24 hours
Clean-up and disposal of old fixtures and boiler	1-2 hours
Total	8 hours-7 days

In most cases, a typically replacement boiler will take one day. However, if you are installing in a new location, you can expect a minimum of 2 days. If you need new ducts or piping, or are removing an underground system, actual work can take as long as 5-7 days.

Buying a boiler direct from manufacturer

In some cases, you may be able to purchase a boiler direct from the manufacturer. This will typically save you anywhere from 25-33% on boiler purchase costs. However, because you can sometimes get a deal for installation and boiler purchase together, it may not be the cheapest way to go.

Can I install a boiler myself? 

No. Unless you are a Gas Safe certified engineer, it is illegal for you to install your own boiler.

Can I get a free boiler?

In some cases, you may qualify for a free boiler under the Energy Companies Obligation (ECO) Scheme. You can visit the OFGEM website to learn more or to find out if you qualify.

You may also qualify for rebates via the Green Deal and you may qualify for the Boiler Scrappage Scheme, where you can get as much as £400 for your old G rated boiler.

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How to Handle a Boiler Sales Representative

Purchasing a boiler typically means getting quotes from multiple sources, which will mean bringing inspectors and sales representatives into your home. Unfortunately, while there are many quality boiler installers, many will also work to get the most money out of you, rather than giving you a fair price. It’s important that you know how to handle them so that you get a good deal.

Purchasing a new boiler can save you money, but it’s important that you get a great boiler and a great deal. By looking out for potential pitfalls, you can avoid issues and make a purchase that represents a great investment.

1. Know what you want

   If you know what type of boiler you have, your general size requirements, and where you want to put your new boiler, you will be at an advantage. By asking for prices on specific boilers and installations, you can get a better quote, and avoid being charged more.

2. Know price ranges

   Similarly, it’s important to know average price ranges. If your quote is higher than expected, ask why and what’s included for the extra money.

3. Mention competitors

   Most boiler installers are highly competitive, and if they know you’ve been talking with their competitors, you may get a better deal.

4. Pressure tactics

   Many sales representatives will try to pressure you into closing a deal same-day, and this is never a good idea. Take your time, do more research, and compare your options.

5. Don’t Agree Same Day

   You have up to 14 days to close a contract by UK law. Any “today only” deals or sales are a scam, unless they are tied to a printed coupon that expires on that date. Be careful and take your time to decide.

If you’re ready to install a new boiler, we can help. Our free comparison service will help you find and compare quotes from the top 4 boiler installers in your area.

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