You might have heard of the term ‘condensing boiler’ before and might not be sure what it is and why you need one! But don’t worry; we’re here to help. This guide will talk about condensing boilers and list the best boiler brands and models on the market.
What is a condensing boiler?
The name ‘condensing’ comes from how the boiler works. Head over to our blog to find out how a condensing boiler works.
Condensing boilers are found in most UK homes today – thanks to the introduction of ‘Boiler Plus’ legislation in 2005.
Condensing boilers are designed to help improve energy efficiency. They run on gas or oil, and they can collect the gas generated by burning fuels and then use it to heat the cold water entering the system, which helps save money and reduces carbon emissions.
In a nutshell, condensing boilers are better for the environment and can help reduce your energy bills.
What’s the difference between a condensing and a non-condensing boiler?
Non-condensing boilers, also referred to as open vent boilers, typically take air from inside the room. In contrast, condensing boilers are fully sealed to ensure heat insulation and take their air from outside. With the latest designs for combi boilers, being sealed reduces the risk of anything being sucked inside your boiler and breaking it.
One of the main differences between a condensing and a non-condensing boiler is the amount of useable heat produced.
Another difference is that non-condensing boilers only have one heat exchanger. Those who still have a non-condensing boiler in their homes can often see the waste gases released from their flue.
Most condensing boilers have two heat exchangers to increase efficiency. If you want more information on a heat exchanger, we cover this in another blog; don’t forget to check it out.
What are the best condensing boiler brands and models in 2023?
If you’re in the market for a new boiler, you must’ve heard of one of these top 3 condensing boiler brands before;
- Worcester Bosch
- Viessmann
- Vaillant
- Baxi
- Ideal
Here is an overview of the boiler brands and their best models;
1. Worcester Bosch Boilers
Worcester Bosch is by far the best boiler brand out there. It is the Rolls-Royce of boilers!
YouGov ranked Worcester Bosch in the top 3 as one of the most popular home appliance brands (Q1 2022).
It’s no surprise that Worcester Bosch came first according to Which? Best Boiler Brand survey 2022.
Here’s why they are the best;
- Awarded a Which? Best Buy for 10-years running
- 10 years guarantee (with WarmZilla)
- Excellent reliability and build quality
- Parts are relatively easy to find
- Excellent customer reviews (rated 4.6 on Trustpilot)
- Brilliant aftercare
- High efficiency (A-rated) boilers
- Hydrogen blend ready
Top 3 best condensing boiler models - Worcester Bosch boilers
Worcester Bosch Greenstar 2000 Combi Gas Boiler
The Worcester Bosch Greenstar 2000 combi gas boiler is available in two sizes; 25kW and 30kW.
The Greenstar 2000 25kW is named one of the quietest combi gas boilers on the market, at 45dB.
With an efficiency rating of 93%, the Greenstar 2000 is a highly reliable combi boiler which can help reduce your current energy bills.
This combi boiler range is perfect for medium to larger-sized homes with up to 20 radiators and 1-2 bathrooms.
Worcester Bosch Greenstar 2000 Combi Gas Boiler Features;
- Bosch engineered quality at an affordable price
- The perfect size for fitting between your wall-mounted kitchen cupboards
- Incredibly quiet when in use, it’s our quietest Worcester Bosch combi boiler
- Features our innovative Quick Tap water-saving feature, which is activated with a quick open and close of a hot water tap. This helps to reduce water wastage in your home
- Perfect for small to medium-sized homes with one bathroom
- Peace of mind with a 10-year guarantee on the primary heat exchanger
Worcester Bosch Greenstar 4000 Combi Gas Boiler
The Worcester Bosch Greenstar 4000 combi gas boiler is available in two kW outputs. These include a 25kW model and a 30kW model.
The new Greenstar 4000 range is Worcester Bosch’s latest edition to the family and will be replacing the Greenstar i combi range. It sits neatly in between the Worcester Bosch 2000 and the Worcester Bosch 8000 Life and Style range.
The Worcester Bosch Greenstar 4000 is one of the most efficient combi boilers on the market, with an efficiency of 94% and an ErP A-rating.
Worcester Bosch Greenstar 4000 Combi Gas Boiler Features;
- Perfect for small to medium-sized homes with one bathroom
- One of the quietest combi boilers available, making it easy to live with
- A wide power range helps to reduce gas consumption and lower energy bills
- Innovative ‘Quick Tap’ water-saving function enables you to reduce water waste
- The modern new design comes with an easy-to-use colour display
- Operates extremely well in low water pressure areas, ensuring robust and warm showers
- One of the quietest combi boilers available, making it easy to live with
- Features wireless connectivity with the Bosch EasyControl
- Instantaneous hot water always available
Worcester Bosch Greenstar 8000 Style Combi Gas Boiler
The Worcester Bosch Greenstar 8000 Style combi gas boiler is available in five kW sizes, including the 30kW, 35kW, 40kW, 45kW and 50kW.
With such a wide range of kW size options, this combi boiler is ideal for medium to larger homes with up to 20 radiators and 2+ bathrooms.
This combi boiler range comes in two colour options, a black or white high-gloss finish, perfect for homes with more modern decor.
Worcester Bosch Greenstar 8000 Style Combi Gas Boiler Features;
- Available with our longest ever guarantee
- Optional unique Intelligent Filling System
- Wireless connectivity with our smart thermostat, the Bosch EasyControl
- Easy-to-use full-colour boiler display
- One of our quietest boilers to date
- Stunning design-led boiler available in a high gloss black or white
- Part of Bosch’s most powerful wall-hung boiler range, effortlessly heating larger homes
- Our most connected and intelligent boiler, with wireless connectivity to the Bosch EasyControl
2. Viessmann Boilers
Viessmann offers a full range of high-quality products representing German engineering at its finest.
They manufacture highly reliable boilers with outstanding performance, which is one reason Viessmann constantly picks up the Which? Best Buy award.
Why choose Viessmann?
- Stainless steel heat exchanger*
- 10 years guarantee (with WarmZilla)
- Great customer reviews (rated 4.4 on Trustpilot)
- Energy-efficient boilers
- Easy to service and repair
- Known for its great aftercare
*The benefits of a Stainless steel heat exchanger
There are many benefits of using stainless steel for the heat exchanger. First, stainless steel offers impressive resistance against corrosion, meaning your heat exchanger is more likely to last for longer and maintain its efficiency, saving you money on your heating bills.
Second, stainless steel heat exchangers can withstand a higher flow rate than exchangers made from other materials. If more gas or water can pass through faster, your water can be heated up more quickly. This increased flow rate also minimises the risk of blockages within the exchanger from debris or rust, which could increase its lifespan.
Finally, stainless steel is self-cleaning and a very lightweight material, making it ideal for various appliances that require water to be heated.
All Viessmann’s condensing boilers have stainless steel heat exchangers, so you can be assured that your boiler will run at maximum efficiency.
Top 3 best condensing boiler models - Viessmann boilers
Viessmann Vitodens 050-W Combi Gas Boiler
Viessmann Vitodens 050-W Combi Gas Boiler Key Features
- Weather compensation accessories
- A plug-in time clock
- Wireless receiver options
- Stainless steel heat exchanger
- User-friendly controls
- 7-day programming
- 7” colour touchscreen for maximum control and comfort in your home
- Integrated WiFi, meaning that it can be used with the ViCare app
- Built-in frost protection
- Easy-to-use controls
Viessmann Vitodens 100-W Combi Gas Boiler
Viessmann Vitodens 100-W Combi Gas Boiler Key Features
- Backlit LCD touch-screen display
- Frontal access to the boiler for easy maintenance
- An Inox-Radial heat exchanger with an extended 10-year warranty
- Optional Vitotrol 100 controls
- 7-day timer
- Easy-to-use controls
Viessmann Vitodens 111-W Storage Combi Gas Boiler
The Viessmann Vitodens 111-W Combi boilers range is available in two kW output options of 26kW and 35kW. Thanks to its high-efficiency rating of 94% and an ErP A-rating, the Vitodens 111-W 26kW is a reliable combi gas boiler that stores domestic hot water within an integrated 46-litre unvented cylinder.
Viessmann Vitodens 111-W Storage Combi Gas Boiler Key Features
- Backlit LCD touch-screen display
- Frontal access to the boiler for easy maintenance
- Optional Vitotrol 100 controls
- 7-day timer
- Built-in temperature sensor
- Easy-to-use controls
3. Vaillant boilers
Vaillant is another great German-owned brand. Although Vaillant offers German engineering and design, all its boilers are made in the UK.
The Vaillant boiler range has been given a Which? Best Buy award has also been awarded a Quiet Mark Accreditation from the Noise Abatement Society.
Why choose Vaillant?
- 10 years guarantee (with WarmZilla)
- Great customer reviews (rated 4.6 on Trustpilot)
- Parts are relatively easy to find
- Energy-efficient boilers
- Easy to service and repair
- Brilliant aftercare
Top 3 best condensing boiler models - Vaillant boilers
Vaillant ecoFIT Pure combi
Vaillant ecoFIT Pure combi key features
- High-performance build, smart controls, and efficiency
- Compact enough to fit in a kitchen cupboard
- Hand-built in Vaillant’s award-winning Derbyshire manufacturing plant
- Quiet Mark approved, meaning it’s one of the quietest products in its category
- 2 years guarantee as standard
- Aluminium heat exchanger
Vaillant ecoTEC Exclusive combi - (The premium option)
The ecoTEC Exclusive is Vaillant’s premium combination boiler. Available in 35kW or 43kW outputs, suitable for medium and large homes.
Vaillant ecoTEC Exclusive key features
- Winner of the Housebuilder Products Awards 2018
- The best in boiler performance, control, and efficiency
- Eco-friendly and 85% recyclable
- Fully compatible with vSMART™ heating control
- 14.5 (35kW) & 17.8 (43kW) litres per minute flow rate
- Quiet Mark approved
Vaillant ecoTEC Pro combi - (The budget option)
Vaillant ecoTEC Pro key features
- Precision heating to reduce your fuel bills
- Hand-built in Vaillant’s award-winning Derbyshire manufacturing plant
- 2-years guarantee as standard
- Quiet Mark approved
- Stainless-steel heat exchanger
4. Baxi boilers
Baxi Heating have been manufacturing boilers in the UK since 1866. According to Which?, “Baxi is one of only three brands to earn five stars for ease of servicing”. Their boilers are known for their reliability and durability. They offer great customer service.
Why choose Baxi?
- 7-years guarantee
- Good customer reviews (rated 4.5 on Trustpilot)
- Made in the UK – Parts are relatively easy to find
- Energy-efficient boilers
- Easy to service and repair
- Great aftercare
Note – unfortunately, WarmZilla does not currently sell Baxi boilers.
Top 3 best condensing boiler models - Baxi boilers
Baxi 600
Baxi 600 key features
- 24kW, 30kW and 36kW
- Compact cupboard fit
- Pipes behind facility within boiler casing
- From only 29.2kg lift weight
- Easy-Fill permanent filling link makes it easier you to top up system
- Brass hydraulics block
- OpenTherm interface
- Compatible with uSense smart control
- Simple hanging bracket
- Choice of flue lengths
- Combine this product with a uSense to be Boiler Plus compliant
- Certified to work with 20% hydrogen
Platinum Combi Gas Boiler
Platinum Combi Gas Boiler Key features
- Easy to install
- 24, 28, 33 and 40 KW
- Full wall mounting jig
- Choice of flue lengths
- Range of plug-in timers
- Front access to all parts
- 1 metre lead provided
- Compatible with uSense smart control using the 230v switch live
Baxi Duo-Tec Combi
Reliable and easy to install, you can be assured of the Baxi Duo-tec’s energy efficiency.
Baxi Duo-Tec Key Features
- Easy to install
- 24, 28, 33, 40 kW
- Dedicated 28kW LPG model
- Easy to install and service
- Flow rate up to 16.4 l/min
- Full wall mounting jig
- Choice of flue lengths
- Compatible with uSense smart control using the 230v switch live
5. Ideal boilers
Ideal boilers were founded in 1905, giving them over 100 years of experience in delivering boilers to homes throughout the UK.
Ideal offers budget-priced boilers at mid-range quality, with exceptional customer service. WarmZilla is proud to offer Ideal boilers as they meet the WarmZilla standards for reliability, price, and aftercare.
Why do we recommend ideal boilers?
- Affordable boilers – pricepoint suitable for landlords and those on a budget
- 10 years guarantee (with WarmZilla)
- Fantastic customer reviews (rated 4.8 on Trustpilot)
- Parts are relatively easy to find
- Energy-efficient boilers
- Easy to service and repair
- Excellent aftercare
Top 3 best condensing boiler models - Ideal boilers
Ideal Logic Max
The Ideal Logic Max range is Ideal’s premium boiler. It has all of the fantastic features and benefits you get with the Ideal Logic Plus range but with some added extras.
The Ideal Logic Max combi boiler range is available in kW outputs of 24kW, 30kW and 35kW, perfect for small to medium-sized homes with moderate demand for central heating and instant hot water. With such a large range of combination boilers to choose from, there is a boiler suitable for every home.
Ideal Logic Max key features
- Designed and manufactured in the UK, meaning that parts are easy to get hold of
- Comes with a standard 10-year parts and labour warranty
- ErP Compliant
- Built-in frost protection for added peace of mind
- Compact cupboard fit design for easy, straightforward installation
- Easy access for ease of commissioning and future servicing
- Low lift weight
- Hard-wearing and scratch-resistant casing for longevity
- Easy to reach pressure gauge on the front panel
- A large display screen for easy reading
- Service timer with telephone number display/service display
- Compatible with several Ideal controls
Ideal Logic Plus
The Ideal Plus range is known for being Ideal’s middle-of-the-range boilers when it comes to price, however, this does not reflect the quality of the boilers. Supported by the Queen’s Award for Enterprise 2013 and the Good Housekeeping Reader Recommended Status in 2013 and 2017, the Ideal Logic Plus range is another highly reliable and efficient boiler range.
Ideal Logic Plus key features
- Made in the UK, so parts are easy to get hold of
- Quiet Mark Approved
- Compact cupboard fit design
- Low lift weight for easy installation
- Built-in frost protection for extra peace of mind
- Energy Saving Trust endorsed
- LPG conversion available for the 30kW model
- Comes with a standard 7-year warranty
- 10-year warranty on the heat exchanger
- Back-lit LCD display screen
- Scratch-resistant casing
- Ready for 20% Hydrogen
Ideal Logic
The Ideal Logic range is known as Ideal’s budget-friendly boiler. This boiler is the least expensive of the Ideal boiler ranges, however, they are still known to be a reliable and robust boiler model.
The Ideal Logic range also includes the same kW outputs as the Ideal Logic Plus and the Ideal Logic Max. A 24kW, 30kW and 35kW boiler model is available in the ideal combi boiler range.
Ideal Logic key features
- Low lift weight
- Compact cupboard design for easy installation
- Scratch-resistant casing
- Built-in frost prediction for extra peace of mind
- 2 years standard warranty
- 10-years warranty on the heat exchanger
- User-friendly heating controls
- LCD display screen
To sum up, here is a side-by-side comparison of the top 5 condensing boiler brands.
| Brand | Overall Score | Reliability Score | Brand Customer Score | Brand Engineer Overall Score | Price for a 30kW Combi |
| Worcester Bosch | 84% | 5 stars | 5 stars | 4 stars | £800-£2,460* |
| Viessmann | 81% | 5 stars | 5 stars | 4 stars | £780-£1,280* |
| Vaillant | 76% | 4 stars | 4 stars | 5 stars | £1,160-£1,410* |
| BAXI | 76% | 5 stars | 4 stars | 4 stars | £880-£1,000* |
| Ideal | 74% | 5 stars | 4 stars | 4 stars | £590-£1,270* |
Source – which.co.uk
The benefits of having a condensing boiler
- Energy-efficient – condensing boilers are much more energy-efficient than old non-condensing boilers, leading to the next point.
- Save you money on your heating bill – because modern condensing boilers are energy-efficient, they reduce your energy bills.
- More environmentally friendly – modern condensing boilers reduce your home’s carbon emissions.
Condensing boilers are designed to help improve energy efficiency. They run on gas or oil, and they can collect the gas generated by burning fuels and then use it to heat the cold water entering the system, which helps save money and reduces carbon emissions.
Certainly! Condensing boilers are found in most UK homes today. They are better for the environment and can help reduce your energy bills.
You can expect condensing boilers to last around 15 years or even longer if it was well maintained.
The top 5 condensing boiler brands are; Worcester Bosch, Viessmann, Vaillant, Baxi & Ideal.
*Average boiler prices were taken from an online heating supplier on the 8th of June 2022. Prices are for the boiler alone and may be subject to change
