Need A New Combi Boiler? Get Supply & Fit Quotes Today!
Choose To Compare Local Quotes Or Get An Instant Online Quote From Our Partners.
Combi Boiler prices can vary hugely and depend on numerous factors, home size, output, brand, warranty, etc… but generally you can expect to pay anywhere between £500 to £1,500 for a new Combi Boiler—plus extra for the fitting.
When choosing a new Combi Boiler it’s important to get the right size and power output (kW output) relative to your home, this will ensure your Combi Boiler can sufficiently support your home’s heating needs.
Our ‘Combi Boiler Prices Fitted Guide’ lists suitable Combi Boiler options (for specific home sizes) together with particulars, allowing you to compare models, warranties and prices—we also detail certain fitting (only) scenarios (see Combi Boiler Prices Fitted) allowing you to gauge expected fitting prices.
* This guide was designed to give you a quick idea of expected Combi Boiler & fitting prices, however, we’d always recommend you seek advice from a qualified installer with regards to boiler size and output.
The following Combi Boilers are well suited to homes with 1–2 bedrooms, typically requiring a boiler output between 24kW and 27kW.
| Brand/Model | Size/Output | Efficiency | Warranty | Price |
|---|---|---|---|---|
| Brand: Worcester Bosch Greenstar 4000 | Size/Output: 25kW | A | Warranty: 10 years* | Price: £1,050 |
| Brand: Ideal Logic Max Combi | Size/Output: 24kW | A | Warranty: 10 years | Price: £950 |
| Brand: Vaillant ecoTEC Plus | Size/Output: 25kW | A | Warranty: 7–10 years* | Price: £1,150 |
| Brand: Baxi 800 Combi | Size/Output: 24kW | A | Warranty: 10 years | Price: £980 |
| Brand: Viessmann Vitodens 050-W | Size/Output: 25kW | A | Warranty: 7 years | Price: £900 |
* Extended warranties may require an accredited installer, registration, and annual servicing.
The following Combi Boilers are suitable for homes with 3–4 bedrooms, typically requiring a boiler output between 28kW and 34kW.
| Brand/Model | Size/Output | Efficiency | Warranty | Price |
|---|---|---|---|---|
| Brand: Worcester Bosch Greenstar 8000 Style | Size/Output: 30kW | A | Warranty: 10 years* | Price: £1,450 |
| Brand: Ideal Logic Max Combi | Size/Output: 30kW | A | Warranty: 10 years | Price: £1,050 |
| Brand: Vaillant ecoTEC Plus | Size/Output: 32kW | A | Warranty: 7–10 years* | Price: £1,350 |
| Brand: Baxi 800 Platinum+ | Size/Output: 33kW | A | Warranty: 10 years | Price: £1,100 |
| Brand: Viessmann Vitodens 100-W | Size/Output: 32kW | A | Warranty: 10 years | Price: £1,200 |
* Extended warranties may require an accredited installer, registration, and annual servicing.
The following Combi Boilers are suitable for larger homes with 4+ bedrooms, typically requiring a boiler output between 35kW and 42kW to meet higher hot water demand.
| Brand/Model | Size/Output | Efficiency | Warranty | Price |
|---|---|---|---|---|
| Brand: Worcester Bosch Greenstar 8000 Life | Size/Output: 35kW | A | Warranty: 10 years* | Price: £1,600 |
| Brand: Vaillant ecoTEC Plus | Size/Output: 38kW | A | Warranty: 7–10 years* | Price: £1,550 |
| Brand: Ideal Vogue Max Combi | Size/Output: 40kW | A | Warranty: 12 years | Price: £1,450 |
| Brand: Baxi 800 Platinum+ | Size/Output: 40kW | A | Warranty: 10 years | Price: £1,300 |
| Brand: Viessmann Vitodens 200-W | Size/Output: 42kW | A | Warranty: 10 years | Price: £1,650 |
* Extended warranties may require an accredited installer, registration, and annual servicing.
You’d be right in thinking that Combi Boilers are generally more cost-effective to install than Regular Boilers (also known as conventional, traditional or heat-only boilers). This is because there are fewer components involved, and a Combi Boiler does not require a separate hot water cylinder or loft feed tank. Their compact size also means they can usually be installed in a wide range of locations around the home.
A straightforward like-for-like Combi Boiler replacement (installed in the same location) typically costs between £1,800–£3,200 fully fitted. If the new boiler needs to be relocated, additional pipework, flue alterations and labour time increase the overall cost, with prices generally ranging from £2,200–£3,800.
Converting from a System or Regular (Conventional) Boiler to a Combi Boiler is a more complex installation. This type of upgrade often involves removing the hot water cylinder and any loft tanks, modifying pipework, upgrading the gas supply if required, and installing new controls. As a result, installation costs are higher.
The table below provides a general guide to typical UK installed Combi Boiler prices.
| Scenario | Typical Price (Installed) |
|---|---|
| Scenario: Replacing a Combi Boiler with a new Combi Boiler in the same location | Price: £1,800–£3,200 |
| Scenario: Replacing a Combi Boiler with a new Combi Boiler in a different location | Price: £2,200–£3,800 |
| Scenario: Replacing a System Boiler with a new Combi Boiler | Price: £2,500–£4,500 |
| Scenario: Replacing a Regular Boiler with a new Combi Boiler | Price: £2,700–£4,800 |
*Prices reflect typical UK installation costs and may vary depending on property layout, boiler brand and output, flue positioning, condensate routing, gas pipe upgrades, system flushing requirements, heating controls, and overall labour time.
Combi Boilers are a popular choice if you want to free up space in your home and don’t regularly require hot water to be delivered to multiple bathrooms at the same time. Because they heat water on demand and don’t require a separate hot water cylinder, they’re ideal for small to medium-sized properties where efficiency and space-saving are important.
If you decide a Combi Boiler is right for your home, the next question is: when is the best time to have your new boiler fitted?
While some homeowners need a boiler fitted urgently following a breakdown, planning ahead is usually the better option. Many people choose to have their Combi Boiler fitted during wider renovation or refurbishment projects. This makes it easier to carry out pipework adjustments, upgrade heating controls, add or replace radiators, and ensure the system is set up for maximum efficiency. It’s also an ideal opportunity to improve insulation, helping your new heating system retain heat more effectively and reduce energy bills.
We also recommend arranging to have your Combi Boiler fitted well before the colder months. Demand for engineers naturally increases as temperatures drop, which can affect availability and pricing. Having your boiler fitted outside of peak periods can help secure better value and ensure your heating system is fully prepared when you need it most.
Our recommendations are based on installer feedback, proven reliability, warranty strength, and long-term running costs.
Installer-Rated Combi Boiler Picks
| Category | Brand / Model | Why It’s Recommended |
|---|---|---|
| Category: Best Overall | Boiler: Worcester Bosch Greenstar 4000 | Why: Excellent reliability, strong UK support network, long warranty options |
| Category: Most Reliable | Boiler: Vaillant ecoTEC Plus | Why: Proven engineering, quiet operation, excellent modulation and build quality |
| Category: Best Warranty | Boiler: Ideal Logic Max | Why: Long warranty periods and good value for money across the range |
| Category: Best Efficiency | Boiler: Viessmann Vitodens 100-W | Why: High efficiency, well-engineered components, strong reliability reputation |
| Category: Best Mid-Range | Boiler: Baxi 800 Platinum+ | Why: Good performance, long warranty, and wide installer familiarity |
* Need advice on your new Combi Boiler? then complete our Quick Quote Form, we'll then arrange for someone to contact you to discuss your requirements and budget further.
