James Elston
Published February 28, 2024
Are you looking for the best combi boiler on the market? There are numerous options to choose from, which can be overwhelming. You may need a new combi boiler because your old one conked out, or want to reduce your energy bills.
Whatever the reason, our guide covers the 16 best combi boilers in the UK from the top boiler manufacturers. We will also dive into how to choose the best combi boilers and other common queries.
Contents
- 1 The Top 16 Combi Boilers In The UK
- 2 Best Viessmann Combi Boilers
- 3 Best Worcester Bosch Combi Boilers
- 4 Best Ideal Combi Boilers
- 5 Best Vaillant Combi Boilers
- 6 Best Baxi Combi Boilers
- 7 Best Vokera Combi Boilers
- 8 Best Potterson Combi Boilers
- 9 Best Other Combi Boilers In The UK
- 10 How We Chose The Best Combi Boilers
- 11 How To Pick The Best Combi Boiler
- 12 FAQs
- 13 Conclusion
The Top 16 Combi Boilers In The UK
- Viessmann Vitodens 050-W
- Viessmann Vitodens 100-W
- Worcester Greenstar 8000 Combi
- Worcester Bosch CDi Compact
- Ideal Vogue Max 32
- Ideal Logic+
- Vaillant ecoFIT Pure 825C
- Vaillant ecoTec Plus
- Baxi 800 Combi Gas Boiler
- Baxi Duo-tec Combi
- Vokera Evolve C Combi Boiler
- Vokera Easi-Heat i 25C
- Potterton Gold Combi
- Potterton Titanium 28
- Glow Worm Energy7 30C
- Alpha E-Tec NX
Best Viessmann Combi Boilers
Viessmann is a top boiler manufacturer that uses German engineering to produce efficient and affordable central heating. Their Vitodens range is remarkable, and are easily considered among the best combi boilers on the UK market. The company has been in the industry for over 100 years and offers a wide range of heating solutions, from combi boilers to solar thermal systems.
1. Viessmann Vitodens 050-W
You’ll find many raving reviews about the Viessmann Vitodens 050-W. This gas boiler is available in 25kW, 30kW and 35kW. It also has a compact size so it can be easily hidden in a cupboard, making it well-suited for small and medium-sized homes. Plus, you can expect an easy installation. Check out our guide on the best 30kW combi boilers if you’re thinking about buying one.
- It is a hydrogen-ready boiler that can come into use when the UK Government implements its net zero plan to switch from fossil fuel gas to hydrogen gas.
- It has built-in wifi compatibility, so it can be easily connected with smart thermostats. With a smart thermostat, you can switch your boiler on and off remotely.
- It is a compact boiler, measuring 400 mm (w) x 350 mm (d) x 707 mm (h) and weighs 36 kg.
- Domestic Hot Water (DHW) flow rate of 12–13.4 litres a minute.
- It comes with a standard three-year guarantee which can be increased to 10 years if it’s installed by a Viessmann-trained installer.
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2. Viessmann Vitodens 100 W
- Hydrogen-blend ready.
- One of the most energy-efficient condensing gas boilers with a rating of 94%.
- Stainless steel heat exchanger which lasts longer than those made of aluminium.
- It is compact at 400 mm (w) x 360 mm (d) x 700 mm (h) and weighs around 35 kg. This makes it kitchen-cupboard friendly!
- The 100-W has built-in wifi and and user-friendly touchscreen display.
The Viessmann Vitodens 100-W is a reliable combi boiler that suits larger homes. Domestic hot water and central heating are no problem for this beast of a combi boiler.
There are three outputs available, including 26 kW, 30 kW, and 35 kW. The 30 kW combi boiler can support a four-bedroom house with two bathrooms and up to 15 radiators. Alternatively, the 35 kW can handle more rooms, bathrooms, and 20 radiators.
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Best Worcester Bosch Combi Boilers
Worcester boiler reviews reveal that the brand is known for exceptional quality. If you’d like your combi to last for years to come, Worcester Bosch boilers have a reputation for lasting up to 15 years – possibly even more. Their guarantee of up to 12 years is also something customers appreciate. The brand is also known for great customer service.
1. Worcester Bosch Greenstar 8000
- A-rated with a commendable 94% efficiency rating.
- Hydrogen-blend-ready.
- The boiler size is 440 mm (w) x 365 mm (d) x 780 mm (h) and weighs 62 kg.
- You can get Greenstar 8000 combi boilers in multiple outputs from 30 kW to 50 kW.
- Intelligent Filling System technology maintains optimum water pressure and alerts you if something goes wrong with the boiler.
- A full-colour touchscreen display with advanced features.
The Worcester Bosch Greenstar 8000 is available in both combi boiler and system boiler versions. The Greenstar 8000 combi boiler is worth raving about. It is sleek-looking, well-built, powerful, and super energy efficient.
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2. Worcester Bosch CDi Compact
- An ErP rating of A, with 94% energy efficiency.
- The CDi Compact stays true to its name, measuring 390 mm (w) x 280 mm (d) x 680 mm (h) and weighing only 32.9 kg.
- Comes in three options: 28 kW, 32 kW, and 36 kW.
- Hydrogen-blend ready.
- The boiler can sync with smart thermostats.
The CDi Compact offers high build quality, user-friendliness and energy efficiency. The high efficiency allows you to save on energy bills while still enjoying uninterrupted heat. The CDi Compact is also ideal for apartments because it’s small. In fact, it is one of the most compact combi boilers on the market!
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Best Ideal Combi Boilers
Ideal boiler prices are cheaper than average while packing a punch in quality. Ideal is a competitive brand with tempting gas boiler options. The company aims to bring harmony between energy efficiency, technology, and quality – and they do it well.
1. Ideal Vogue Max 32
- Stylish design with a user-friendly LCD interface.
- Full modulation and built-in frost protection.
- Available in outputs of 15 kW, 18 kW, and 26 kW.
- The dimensions are 330 mm (d) x 450 mm (w) x 740 mm (h), weighing 38.9 kg.
- Hydrogen-blend-ready.
This is easily one the best combi boilers money can buy. Why? Their low prices are paired with a multitude of benefits that competitors have yet to match in terms of affordability. From money-saving efficiency ratings to high-quality materials, the Ideal Vogue Max 32 is a force to be reckoned with. This model suits medium homes with 3+ bedrooms and up to 14 radiators.
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2. Ideal Logic+
- A-rated, 94% energy efficiency.
- User-friendly, backlit LCD screen.
- The size measures 395 mm (w) x 278 mm (d) x 700 mm (h) and weighs 34 kg.
- Frost protection features that can brave the cold UK weather without freezing up.
- The available outputs include 24 kW, 30 kW and 35 kW
Looking for the best combi boiler for a medium-sized home? Consider the Ideal Logic+ with a 35 kW output option, which can handle around two bathrooms and 20 radiators. This model is also one of the most affordable energy-efficient combi boilers on the UK market.
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Best Vaillant Combi Boilers
Vaillant is a well-reviewed German boiler manufacturer and is seen as one of the best companies for combi boilers. They have a high rating among clients, and their products are durable, with boilers lasting up to 15 years. One notable feature of the brand is that its products are hand-built to ensure only the best quality.
1. Vaillant EcoTec Plus
- An ErP A rating, with an operation of 89.3% efficiency.
- The boiler size is 440 mm (w) x 338 mm (d) x 720 mm (h) and 36 kg – which is still small enough to fit into a cupboard.
- You can opt for a 35 kW or 38 kW output.
- You can pair the EcoTec Plus with a smart thermostat to control the boiler according to your heating needs.
This condensing combination boiler is one of the most popular choices. It is an affordable, effective combi that suits medium-sized homes with up to two bathrooms and 15 radiators. The EcoTec Plus is also a quieter combi boiler compared to other brands like Worcester Bosch and Baxi.
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1. Vaillant EcoTec Plus
- You can choose an output range of 25 kW, 30 kW or 35 kW.
- A-grade, 89.3% efficiency rating.
- Hydrogen-blend-ready.
- It has compact dimensions, measuring 390 mm (w) x 295 mm (d) x 700 mm (h) and weighs around 33 kg.
The Vaillant ecoFIT Pure 825C is one of the best combi boilers thanks to its value for money. It is not as high-tech as those in the Worcester Bosch Greenstar range, but it does give you everything you need at a reasonable price. These gas combi boilers are perfect for flats and smaller homes.
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Best Baxi Combi Boilers
If you’re looking for a new combi boiler, you’ve likely considered Baxi – one of the most popular boiler manufacturers known for their affordability and reliability. They have been around for over 150 years and know the industry well. They also cater to various price ranges while maintaining quality.
1. Baxi 800 Combi Gas Boiler
- An A-rated combi boiler with a 93% energy efficiency rating.
- This boiler is available in central heating outputs of 25 kW, 30 kW, and 36 kW.
- The 800 Combi has a compact, cupboard-friendly size. The measurements are 390 mm (w) x 285 mm (d) x 700 mm (h).
- Hydrogen-blend-ready.
- The Baxi 800 can connect to a smart thermostat, allowing you to control your heating remotely.
If a top-of-the-range gas combi boiler doesn’t fit your budget,Baxi boiler prices will save the day. This is especially true for the 800 Combi. This option is energy-saving, powerful, and affordable. It offers everything you need and can support a four-bedroom, two-bathroom home with 10 radiators.
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2. Baxi Duo-tec Combi
- The Duo-tec gas combi boiler has an impressive 92% rating.
- The boiler measurements are 450 mm (w) x 345 mm (d) x 780 mm (h), which is small enough for cupboard spaces.
- You can get a Duo-tec combi boiler in 24 kW, 28 kW, 33 kW, and 40 kW outputs.
The Baxi Duo-tec is a popular combi boiler installed in many UK homes. This tried-and-tested model is easy to install and maintain. It is also so simple to use that even your six-year-old could understand how to work it. The Baxi Duo-tec has a range of outputs to suit almost all heating and hot water needs.
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Best Vokera Combi Boilers
Vokera is a budget option if you don’t want to spend much on a new boiler. They have many combi boilers on offer, but the Evolve C Combi Gas Boiler and Easi-Heat i 25C are the best options.
1. Vokera Evolve C Combi Gas Boiler
- The Evolve C has an impressive 92% and an ErP A rating.
- This model is available in 24 kW, 28 kW, 32 kW, 36 kW, and 42 kW.
- The dimensions are 420 mm (w) x 275 mm (d) x 740 mm (h).
- A fully backlit LCD screen for easy reading.
- Capable of handling a hydrogen-fossil fuel blend.
Are you in need of a reliable combi boiler? The Vokera Evolve C is all that and more. From its 10-year warranty to its energy effectiveness, this option has it all. In addition, the Evolve C’s many features and benefits make it an advanced and capable model.
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2. Vokera Easi-Heat i 25C
- An 89.1% seasonal efficiency rating.
- Comes in 25 kW, 29 kW and 32 kW outputs.
- This conveniently sized combi boiler is only 400 mm (w) x 275 mm (d) x 700 mm (h) and weighs 28.5 kg.
- Has a built-in digital clock that displays error codes for easy troubleshooting.
- An anti-cycling feature that prevents energy wastage.
The Easi-Heat i 25C is a lightweight, compact combi boiler that allows for easy and flexible installation. This combination boiler only suits smaller homes with low heating needs, ideally with one bathroom and a maximum of 10 radiators.
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Best Potterson Combi Boilers
Potterson is a reputable British brand that has been in the industry for over 150 years. Whatever your hot water and heating needs, Potterson has a reliable, budget option. They are known to cater for almost all sized homes and their boilers can last up to 15 years without repair issues.
1. Potterton Gold Combi
- ErP A-rated and 89% efficient.
- You can choose between outputs of 24 kW, 28 kW, and 33 kW.
- The measurements are 450 mm (w) x 345 mm (d) x 780 mm (h).
- A smart control system that automatically adjusts the heat output to help lower fuel consumption.
- Flexible flue options of up to 20 meters.
The Potterson Gold Combi is available in both gas and LPG models. This boiler is affordable and can suit small to medium homes. Overall, the Gold is a dependable boiler at an affordable price, made with high-quality parts.
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2. Potterton Titanium 28 Combi
- A brilliant 91.1% energy rating.
- You can get outputs of 24 kW, 28 kW, 33 kW and 40 kW.
- The Potterson Titanium 28 measures 450 mm (w) x 345 mm (d) x 780 mm (h) and is wall-mounted.
This Potterson combi boiler is highly efficient and fully capable of meeting your heating and hot water needs. The Energy Saving Trust has also given it its stamp of approval. The Titanium 28 comes in various outputs to suit a wide range of heating demands.
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Best Other Combi Boilers In The UK
Glow-worm and Alpha have some competing combi boilers that deserve a spot on this list. Glow-worm boilers are of high quality with high customer satisfaction ratings to back them.
Alpha boilers are easy on the wallet and the company backs their boilers with up to a 10-year warranty, which says a lot about their reliability. They’re also known to offer brilliant customer service.
1. Glow-worm Energy7 30C
- The efficiency rating is a decent 89.2%
- It is a compact cupboard-friendly size that measures 390 mm (w) x 280 mm (d) x 700 mm (h).
- You can get the Energy7 30C in 25 kW, 30 kW, and 30 kW.
- Top and rear flue options for easy installation.
This excellent medium-budget boiler has a lot to offer. The Energy7 30C has an attractive design that’s simple to understand, and it’s available in various energy outputs. It is also small enough to hide away in a cupboard and suits a three-bedroom house with one bathroom and low hot water needs.
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2. Alpha E-Tec NX
- An impressive seasonal efficiency of 93%
- The model is available in outputs of 28 kW and 38 kW.
- The dimensions are 440 mm (w) x 255 mm (d) x 712 mm (h).
- Zinc-plated expansion vessel that helps prevent corrosion.
- A high flow rate of 14.1 litres per minute.
The E-Tec NX is a budget option for small-to-medium apartments and homes. Even though the cost might say otherwise, it is made with quality components. Alpha boilers have a good reputation, and this combi boiler is one of their best options.
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How We Chose The Best Combi Boilers
Customer reviews
We scanned multiple evaluations for each boiler to find only the best money can buy. However, it’s easy to review something from one perspective. That’s why we took what customers had to say into account too.
Value for money
The boilers mentioned balance quality and price. Combi boilers usually average between £500 and £3,000 and installation adds another £500 – £1,000, leaving the entire bill possibly at £4,000. Since a new boiler is a rather large expense, we considered value for money as a key aspect.
Brand reputation
Some of these brands have been in the boiler industry for over 100 years, like Viessmann and Baxi. Others have also passed the 50-year mark. We picked the brands on this list because they’re experienced, reputable, and reliable.
How To Pick The Best Combi Boiler
Choosing the best combi boilers for your home ensures you receive efficient heating and hot water supply. There are various factors to consider, from house size to energy efficiency. Let’s take a look at the key considerations when choosing the best combination boiler.
House size and heating output
The size of your home determines your heating output needs. For example, 24-27 kW combi boilers are generally best for smaller properties or apartments with one bathroom. Larger 3-4 bedroom homes with two bathrooms have a higher hot water demand and will require a 28-34 kW combi boiler. Even larger homes will likely require one that is 35-42 kW.
However, you should consider getting a conventional boiler instead of a combi boiler if you have a bigger house. A combi boiler taps directly into the main water supply which means that it cannot efficiently divide its heat output to large homes that use a large amount of hot water.
Affordability
Cost is one of the most vital factors when buying a combi boiler. While you may be tempted to buy a low-cost option, you should consider the long-term cost, too. Energy efficiency and warranties are factors that save costs in the long run. A high-quality, energy-efficient combi boiler may be pricier upfront; however, you’ll enjoy lower energy and maintenance bills.
On the other hand, it doesn’t always help to break the bank. While some brands have a premium price, there are substitutes that are just as efficient. You also won’t want to buy a high-output boiler when your property doesn’t need it.
Energy efficiency
Combi boilers are often a top choice for their energy efficiency. Energy efficiency allows you to in reduce your CO2 emissions and heating costs. Your boiler will come with an Energy-related Product (ErP) and Seasonal Efficiency of Domestic Boilers in the UK (SEDBUK) rating, which can help you decide which boiler is best.
Almost all modern combi boilers have an ErP rating of A. This means there isn’t much to compare when seeking energy efficiency. When deciding on the best combi boiler, rather use the SEDBUK rating system. It is more helpful because it assigns a percentage (typically between 70% and 92%) that shows how much energy is used and wasted. If the rating says 92%, it loses 8% of its heat during operation.
Some brands use cutting-edge technology to increase heat output while decreasing energy consumption. This is another thing to look for that saves money and helps the environment.
Installation and maintenance
Need some advice on combi boiler installation? It’s best to choose an option compatible with your existing heating system. Speaking to qualified heating engineers will make this task easier, like Eco Happy.
Additionally, buy a boiler from a reputable manufacturer that is reliable and offers good customer support. Regular maintenance is essential to keep your boiler running smoothly for years to come. Therefore, you should also consider warranty coverage and the availability of spare parts when things go wrong.
Customer support and after-sales service
Investing in a combi boiler brand known for exceptional customer service will give you peace of mind and save you from headaches down the line. Read testimonials and reviews so you know what to expect. You can look at aspects like technical assistance, warranty coverage, and responsive customer service.
FAQs
Which is the best combi boiler to buy?
Determining the “best” combi boiler depends on your specific heating needs, budget, and preferences. However, there is a general consensus on which boiler manufacturers offer the best combi boilers. These manufacturers include Worcester Bosch, Vitodens, Vaillant, and Viessmann.
What boilers do plumbers recommend?
Plumbers often suggest Worcester Bosch, Viessmann, and Baxi as being the top-quality boilers in the UK. These well-established brands are long-lasting and trustworthy. However, opinions and recommendations may differ depending on your needs.
Which boiler brand is the most reliable?
Viessmann easily ranks as one of the most reliable boiler brands on the market. The Viessmann Vitodens 050-W and 100-W are the boilers contributing to the brand’s dependability. What’s more, Viessmann offers a 7-year parts and labour warranty if anything goes wrong. You can expect their boiler to last between 15 and 20 years.
Does the Boiler Upgrade Scheme offer help with combi boilers?
The Boiler Upgrade Scheme grant only applies to heating systems that replace fossil fuel heating systems. The options include air and ground source heat pumps or biomass boilers. If you install a biomass combi boiler, you’ll be eligible for up to £5,000.
Conclusion
Many reputable brands in the UK market provide excellent combi boilers. The top picks and customer favourites include Viessmann, Worcester Bosch, Ideal, and Vokera. They’re the best thanks to their high efficiency and quality. The best budget pick would be Baxi.
If you found this article helpful, you may also want to explore our boiler brands to avoid post for additional insights before making your decision.
Eco Happy aims to give you reliable service and insightful information. Feel free to contact us to help you find the best combi boiler for your needs. We’re also happy to give you a quote to compare your options!
James Elston
Boiler Expert
James Elston is the top boiler replacement and heating expert at Eco Happy. He has over 20 years of experience in the industry, focusing on Gas Safe boiler installations and offering home-heating and energy-saving solutions to homeowners across the UK. From sourcing the most energy-efficient combi boiler to providing specialist heating advice, James ensures that Eco Happy maintains the highest standards and best customer service.