Updated October 2025. First published February 2024.
Researching the cost of a boiler replacement is a luxury afforded only to those who plan ahead. If your boiler breaks suddenly, the chances are you’ll opt for whatever’s available at the time so you can switch your heating back on!
If your boiler is still hanging on by a thread or is over ten years old, don’t wait too long to start your research. Plan for it early, and you can shop around to find the best deals on your new boiler.
Key points
– The cost of a new boiler ranges between £600 and £3500 dependent on the type.
– Installation varies between locations and depends on the complexity and size of the job.
– A straightforward boiler installation, on average, costs between £800 and £2,500.
– Switching to a new, more energy-efficient boiler can save you money on your utility bills.
How much is a new boiler?
The cost of a new boiler ranges from £600 to £3500. This covers everything from economy boilers to premium system boilers at the higher end of the scale.
The price you’ll pay depends on several things:
- Type of boiler, e.g. combi boiler vs system boiler vs regular boiler
- Fuel type (gas, oil, electric)
- Size of the boiler
- Make and model (Worcester Bosch, Ideal, Valiant, etc.)
- Length of warranty
We’ve compiled this table of average boiler prices, including installation, to give you an idea of the cost of replacing a boiler.
| Type of boiler | Average price range |
| Combi boiler (gas) | £1,600 – £6,000 |
| System boiler (gas) | £1,600 – £5,000 |
| Conventional boiler | £1,600 – £5,500 |
| Electric | £1,500 – £5,000 |
| Oil | £2,500 – £5,500+ |
These figures are for the boiler and installation only; you may want to add extras, such as smart controls and thermostatic radiator valves.
How much is the installation?
The cost to fit a new boiler varies by location due to differences in hourly labour rates. The cost of a boiler replacement is likely to be higher in London than in the North East.
A straightforward boiler installation, on average, costs between £800 and £2,500 (assuming you’re replacing like-for-like, i.e., replacing a combi boiler with a similar-sized combi boiler).
You can expect to pay more for complex jobs, such as:
- Switching from one type of boiler to another, e.g., a system boiler to a combi boiler
- Increasing the size of your boiler to accommodate an extension/conversion
- Moving the boiler’s location
- Upgrading from an economy to a premium model
- Switching the fuel type (e.g. gas to electric)
In all these cases, the work is likely to take longer, so you can expect to pay more for labour. You may also need additional parts, such as pipework, valves, and pumps.
If you’ve extended your home and need a bigger boiler to heat more rooms, you should also budget for extra radiators.
Smart controls are another optional extra you can request alongside your boiler replacement.
- The average cost of a good-quality smart thermostat is around £200 to £300 for the unit itself, with installation costs potentially adding another £100 to £200.
- The cost of smart radiator valves typically ranges from £30 to £100 each, with some high-end models reaching £150.
Total cost of a new boiler and installation
The average cost of a boiler replacement (supply + installation) in the UK is around £3,800. That’s based on a like-for-like replacement, switching from one type of boiler to a new model of the same kind.
Several other factors, including the complexity of the installation and any additional requirements, will determine the final price.
For a more accurate estimate, we recommend contacting your local heating company.
Average boiler replacement costs by type
The type of boiler and the fuel source (gas, oil, or electric) are big factors in determining the cost of a new boiler.
Replacement combi boiler costs
The average replacement combi boiler costs between £600 and £3500.
Combi boilers heat water on demand, eliminating the need for a hot water cylinder or tank, making them ideal for flats and small to medium-sized properties where space is limited. Space-saving and efficient, combi boilers are popular in the UK, and one of the easiest to fit. You can expect to pay around £1200 for a straightforward installation (excluding additional parts).
Gas boiler replacements cost less to install than oil boilers because they are typically more straightforward to fit, do not require an additional oil storage tank, and benefit from a more established infrastructure for gas supply.
Oil boiler replacement costs
Oil boilers typically cost between £1200 and £3,800.
These boilers are designed for properties that are not connected to the grid, making them an ideal choice for rural homes. Oil boilers operate by burning oil to generate heat, which is used to provide hot water and central heating.
They are renowned for their efficiency and ability to provide consistent heating. However, the installation process can be more complex due to the need for an oil storage tank, which can increase overall costs. You can expect to pay around £2,500 for a straightforward installation of an oil boiler.
Paying for a boiler replacement on finance
The best way to pay for a boiler replacement is in one lump sum, but this isn’t the kind of cash you’ll find down the back of the sofa. If your boiler needs to be replaced in the coming years, start saving now!
If you don’t have years to wait, you also have the option of taking out boiler finance to cover the cost. These plans allow you to spread the cost of your new boiler over a fixed term, so you don’t have the hassle of finding the money up front. Instead, you can make affordable, planned monthly payments. Here’s an illustration of how that might look:
New boiler finance illustration
Replacement boiler cost: £5,000
Deposit: £500
Loan amount: £4,500
Monthly instalments: £187.50 over 24 months, interest-free
There are several deals available with varying terms for you to choose from, allowing you to select one that suits your circumstances. We’ve partnered with Novuna Personal Finance to offer interest-free payment plans on new boiler installations.
How to save money on your boiler replacement
The first thing to know about buying a new boiler is that you don’t have to buy it from your energy provider. Boiler installations from major brands, such as British Gas, will likely cost more than those from your local heating company.
Follow these top tips to bag yourself the best deal on your boiler replacement:
- Ensure you always get three quotes. This is the best way to gauge a sensible quote for your circumstances.
- Consider quotes from Gas Safe-registered engineers only.
- Ask someone to come out and assess the job before committing to an estimate. Without seeing the size and scope of the project, you can’t be assured you’re getting an accurate quote.
- If the estimate isn’t itemised, don’t be afraid to ask how the engineer arrived at that figure.
- If you want to add extras, such as smart heating controls, be sure to mention it at the start of the project. It might cost you more if you decide to add it later.
Finally, before choosing a heating company, check out the online reviews to find out what their customers really thought about the work.
New boiler grants
You may be eligible for a grant to cover part of the cost of replacing your old boiler. The UK Government’s Boiler Upgrade Scheme (BUS) offers grants of up to £7,500 towards the cost of replacing your fossil fuel heating system with an air-source or ground-source heat pump. You can also get up to £5,000 when you switch to a biomass boiler. Find the full details and eligibility criteria on the government’s website.
Additionally, the ECO (Energy Company Obligation) scheme provides support for people on certain benefits to improve their home heating systems. Get help towards the cost of replacing and repairing your old boiler, or with insulation work. This scheme is accessed directly through energy providers – find a full list of those taking part on Ofgem’s website.
Is it worth buying a new boiler?
Your boiler may still be working, but how much longer can you rely on it? If it’s over ten years old, your boiler is unlikely to last much longer. Worse still, older boilers are inefficient and expensive to run.
Unsurprisingly, old boilers use more fuel, which is bad news for your bank balance and the environment.
Switching from a G-rated boiler to an A-rated condensing boiler with a programmer, room thermostat, and thermostatic radiator valves (TRV) could save you £320 on your fuel bill over the year*.
This illustration from the Energy Saving Trust is based on a semi-detached house (the full set of figures is available on the EST website).
Read more: When to Replace your Boiler: 6 Signs you Shouldn’t Ignorea
Boiler replacement cost – your FAQs
Find the answers to your frequently asked questions on the cost of a boiler replacement in the UK.
How much does a boiler replacement cost?
The cost of a new boiler ranges from £600 to £3,500, depending on the size, type, and brand of boiler you choose. You also need to factor in labour, additional parts (if you’re moving your boiler) and extras like smart controls or a magnetic boiler filter.
How much is a Worcester boiler?
You can expect to pay between £900 and £2,500 for a Worcester Bosch boiler. The cost varies according to the size and type of boiler you require.
This is for supply only; you should also factor in installation costs.
Arton Heating is a Worcester Accredited Installer – get a quote today.
Do I need a power flush with my new boiler?
Whether or not you need a power flush with your new boiler installation depends on various factors, including the condition of your existing heating system and the recommendations of your installer.
It’s not mandatory, but it’s often recommended in situations where debris or sludge is already present in the heating system.
Is the government giving grants for new boilers?
The UK government provides grants to assist with the cost of replacing old boilers with more energy-efficient systems. The Boiler Upgrade Scheme (BUS) encourages property owners in England and Wales to replace their existing fossil fuel heating systems with more efficient, low-carbon alternatives, such as heat pumps and biomass boilers. Check your eligibility on the government website.
*Based on July 2025 fuel prices.
