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Best combi boilers in 2023

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Last updated: 26 May 2023

Upgrading your old gas boiler to an energy-efficient, A-rated model is one of the best ways to save money on your energy bills in the current climate. In this guide, we’ll look at 5 of the best combi boilers currently available on the UK market. 

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What is a combi boiler?

Combi boilers are a popular choice for households as they provide instant hot water without the need for a separate cylinder or storage tank. This also means they’re typically much more compact than system boilers, so are perfect for smaller homes without the excess space needed for a chunky central heating system.

How did we choose the best combi boilers?

When scouring the market for the best combi boilers, we only considered products from the best boiler brands. We also looked at a number of categories and specifications that we believe make any particular model stand out from the rest. These include:

  • Technical specifications such as size and output
  • Value for money
  • Customer reviews
  • Reputation of the manufacturer/brand
  • Ease of use, for example if it has built-in controls, WiFi, or smart thermostat compatibility
  • Any awards they’ve won from industry bodies such as Which?
  • Manufacturer’s warranty length

So, let’s take a look at what the best combi boilers in 2023 are, based on these criteria:

Top 5 combi boilers in 2023

Worcester Bosch Greenstar 4000

Worcester Bosch is one of the most recognised brands in the boiler industry, and its Greenstar range of boilers make up its premium level of central heating systems.

Available at a relatively reasonable price, the Greenstar 4000 is Which? recommended boiler and has one awards for its low operating noise – something which will please those who get irked by the constant murmurings coming from the boiler room.

It’s also one of the most well-built and reliable combi boilers on the market right now, which means it’s less likely to break down and need frequent servicing. This fact is backed up by Worcestor Bosch offering up to 10 years of warranty, which shows a decent level of confidence in their product.

The Greenstar 4000 combi boiler comes with two different outputs – 25kW or 30kW – with the higher output being more suited for larger homes with higher hot water demands. It’s also very easy to use, with a backlit touchscreen LED display giving you total control over your hot water and energy expenditure.

Worcester Bosch Greenstar 2000

Another combi boiler from industry-leaders Worcester Bosch’s premium range, the Greenstar 2000 is again one of the best all-round central heating systems that money can buy.

This model is slightly more budget-friendly than the Greenstar 4000, but it is still a very reliable machine, backed up by a warranty of up to 6 years. The fact that it’s also smaller, but just as efficient, makes it a suitable alternative for small to medium-sized households with just 1 or 2 bathrooms.

It’s also hydrogen-ready, which makes it a viable option going into the future as the UK looks to wean itself off of fossil fuels. In fact, the Greenstar 2000 is such a great, relatively low-cost option that it scooped up Which?’s best combi boiler recommendation in 2021.

Viessmann Vitodens 050-w

This central heating system is one of the best all-round boilers you can currently find on the UK market, and you can be sure of its build quality and durability thanks to its German engineering.

It’s a very compact boiler, meaning it can fit easily into your kitchen cabinet, while its also extremely quiet compared to most boilers.

Just like the Worcestor Bosch Greenstar 4000, the Vitodens 050-w combi boiler from Viessmann comes with up to 10 years of warranty, and is also available in either a 25kW or 30kW output.

It’s also compatible with smart thermostats, provides instant hot water on demand, and allows for wireless heating controls via a mobile app – which is great for controlling how much energy you’re using and cutting back on costs.

Viessmann Vitodens 100-W

Another impressive boiler from reliable German manufacturers Viessmann, the Vitodens 100-W combi boiler was recently updated in 2021, and the latest version stands out as one of the company’s best.

It’s hydrogen-ready, which is great as the country begins to wean itself of gas and other fossil fuels, while it also has built-in WiFi, making it super easy to control via smart thermostats or smartphone apps.

Just like the Vitodens 50-W, the 100-W combi boiler has an impressive flow rate of between 12-14 litres per minute, so you can be guaranteed to get hot water pretty instantly. And like most of the best comi boilers on today’s market, it’s backed up by a 10-year warranty.

In fact, not only is the Viessmann Vitodens 100-W ones of the best all-round combi boilers available in the UK, it’s also one of the best-selling models throughout Europe. It’s slightly more powerful than the Vitodens 50-W, and is ideal for medium-sized households with 2 bathrooms.

Ideal Logic C30

This hydrogen-ready combi boiler comes from Ideal, another well-respected British-based heating company. The Logic C30 has quickly become one of the most popular boiler models in the UK, and especially suited for those living in new-build apartments.

It’s super-compact, meaning it can be stored neatly away in a kitchen cupboard or the like, and it’s also very easy to use with wireless heating controls. The winner of Good House Keeping awards in both 2013 and 2017, it’s 10-year warranty shows that Ideal has confidence in the longevity of this product.


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Fergus Cole

Author: Fergus Cole

Fergus is a journalist specialising in the personal finance, energy and broadband sectors. He also has a passion for travel and adventure so tries to make the most of this in any spare time he gets.

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