A new boiler typically costs £1,500–£2,800 for a straightforward like-for-like combi replacement, supplied and fitted, rising to £2,000–£4,000+ for a system boiler and £7,000–£14,000+ before grants for an air-source heat pump.
If your boiler is old, unreliable or becoming more expensive to run, you may be wondering how much a new boiler costs in 2026. The final price depends on the boiler type and brand, the installation requirements, and the condition of your existing heating system. If the installation is more complicated, the cost can be higher, particularly if you are changing boiler type or moving the boiler to a different location.
New Boiler Costs in 2026
| Boiler Type | Typical Cost | Best Suited To |
|---|---|---|
| Combi boiler | £1,500–£2,800+ | Flats and smaller homes |
| System boiler | £2,000–£4,000+ | Larger homes with higher hot-water demand |
| Air-source heat pump | £7,000–£14,000+ before grants | Suitable homes moving away from gas |
These are general UK price guides rather than fixed quotes. Installation requirements can make a significant difference to the final price.
Combi Boiler Cost
A combi boiler heats your central heating and hot water from one compact unit. It does not need a separate hot-water cylinder, making it a popular choice for many UK homes.
For a straightforward replacement, R.W. Miller currently states that a like-for-like combi boiler installation typically costs £1,500–£2,800 supplied and fitted.
The price can increase if the boiler needs to be relocated, pipework needs upgrading or other changes are required.
For many homeowners, a combi is the simplest replacement option when the existing system is already suitable.
System Boiler Cost
A system boiler works with a separate hot-water cylinder. It can be a better option for larger homes where several people may need hot water at the same time.
A system boiler installation generally costs more than a straightforward combi replacement because there are more components involved.
If you already have a system boiler and cylinder, replacing them like-for-like may be relatively straightforward. Converting from a combi to a system boiler, or vice versa, can increase the labour and materials required.
What About a Heat Pump?
Heat pumps have a much higher upfront installation cost than a conventional gas boiler, but government support can reduce the amount homeowners need to pay.
The Boiler Upgrade Scheme currently provides grants of up to £7,500 for eligible heat pump installations.
However, a heat pump installation is not simply a boiler replacement. Your home may need suitable radiators, controls, insulation and electrical or plumbing work.
If you are considering moving away from gas, the total project cost should be compared with the available grant and your property's requirements.
How Much Do Boiler Brands Cost?
The brand you choose also affects the price.
I install boilers from established manufacturers including Worcester Bosch, Vaillant and Ideal.
Different models have different outputs, efficiencies, warranties and prices. The right choice depends on your property and hot-water requirements rather than simply choosing the cheapest model.
A correctly sized boiler and professional installation are more important than paying for the most expensive option.
What Does the Installation Price Include?
When comparing quotes, check what is actually included. A new boiler installation may involve:
- Supply of the boiler
- Removal of the old boiler
- Installation and connection
- Flue installation
- Necessary pipework changes
- System testing and commissioning
- Disposal of the old boiler
- Warranty registration and certification
I provide fixed installation quotations, with the price agreed before work starts. Straightforward installations can often be completed within a day. This makes it easier to compare quotations without being surprised by additional costs later.
What Can Increase the Cost?
The answer to how much a new boiler costs depends heavily on the property and existing system. Your installation could cost more if:
- The boiler needs to be moved
- Pipework needs replacing or upgrading
- You are changing boiler type
- The flue route needs changing
- The heating system requires cleaning or upgrades
- Additional controls or radiators are required
- Access to the existing boiler is difficult
A site assessment is therefore the best way to establish the actual cost.
Can You Pay for a New Boiler Monthly?
Some boiler installers offer finance options, allowing homeowners to spread the cost over monthly payments.
Before choosing finance, check the deposit, interest rate, monthly payment and total amount repayable. Availability and eligibility vary between providers.
Government grants may also help reduce the upfront cost of eligible low-carbon heating systems.
Repair or Replace Your Boiler?
Replacing a boiler is not always necessary. If your boiler is relatively new and has developed a straightforward fault, a repair may make more financial sense.
Replacement becomes more worth considering when an older boiler is breaking down repeatedly, becoming difficult to source parts for or becoming increasingly expensive to maintain.
Getting a professional assessment can help you compare the likely repair costs with the cost of a new installation.
How Much Should You Budget for a New Boiler in 2026?
For a straightforward combi replacement in South London, £1,500–£2,800 supplied and fitted is a useful starting point based on R.W. Miller's current pricing guide.
However, every property is different. The best way to know exactly how much your new boiler will cost is to have your existing system assessed and receive a fixed quotation.
New Boiler Installation in South London
I supply and install combi, system and heat-only boilers across South London and Surrey, including leading brands such as Worcester Bosch, Vaillant and Ideal.
If your existing boiler is approaching the end of its life, arranging a quotation before the colder autumn and winter months can give you time to compare your options. Call Reion directly on 07375 813996, get a boiler installation quote from R.W. Miller, or get in touch with any questions.
