It's the burning question on every savvy boiler buyer's lips. Ruthless German engineering, or belting boilers from a brand as big as Bosch? Here, we drill down in to the positives, the negatives and give our verdict.
Pondering the purchase of a boiler replacement from one of the leading brands, but aren’t quite sure which to choose? Do you take a punt on the German newcomer, or stay with the tried and tested British staple?
Worcester Bosch has been the leading UK boiler brand for decades (that's multiple 10 years), yet, in recent times Viessmann boilers have also established themselves as a top brand. Touché.
Viessmann are you ready?
Worcester Bosch, are you ready?
Check out the latest deals on Worcester and Viessmann boilers here.
Worcester Bosch Boilers Review
Founded in the UK back in swinging 1962, Worcester Bosch has been a big name in the British boiler industry for decades, renowned for their high-quality build and excellent aftercare.
So I was just sat there, minding my own business, I turn around, and out of nowhere.... BOSCH!
Presently, the Greenstar range is Worcester’s most popular selection of combi boilers, offering high efficiency, and a range of power outputs and dimensions, with the CDi compact being small enough for many standard kitchen cupboards. Neat.
Some of the brand's other popular models include the 2000 and 8000, you can read our full reviews of them:
Why Choose Worcester Bosch?
Worcester Bosch is arguably the best-known brand in the UK and is highly regarded among gas installers and consumers.
Want the exact price of a new boiler? Use our boiler quote calculator (no personal details needed).
But why? What are the main advantages of this brand? Let’s slither into the stats...
Which? Best Buy Award Winner for 10 Consecutive Years
The Consumer Association’s Which? The award is well respected by consumers and within the industry for its unbiased surveys, in particular the annual best boiler survey.
Worcester Bosch has been a Which? Best Buy award winner for 10 years in a row, based on the feedback from over 12,000 boilers and over 100 gas boiler installers. Providing the views of the everyday user and professional opinion.
Combined, the survey considers and provides an aggregated score based on the following:
Reliability score
Customer score
Engineer recommendation
Build quality
Availability of parts
Ease of fixing faults
Ease of servicing
No other organisation surveys and collects so much data about boilers, so as you can appreciate, the results are considered to be reliable and trustworthy by many consumers and industry insiders.
Curious to know which boiler brand performed worst? Find out in our report of the worst boilers.
So, what did this year’s Which? survey results show?
Worcester Bosch was awarded full marks for their build quality and availability of parts, two very important factors for any boiler user.
The Worcester Bosch 10-Year Guarantee
Worcester Bosch is unique in that they do not simply offer a traditional warranty, but a no-quibble guarantee.
What’s the difference? Is it just a marketing tactic?
A guarantee is superior to a warranty since it’s an agreement from the manufacturer that they will attend to your property and repair or replace your boiler as soon as possible.
A conventional warranty (offered by most other brands) is a contract to investigate the issue, but not an unconditional agreement to repair the boiler free of charge.
When purchased via Heatable, all Worcester Bosch boilers in the Greenstar Range come with a 10-year-long guarantee.
CORGI’s Domestic Heating Product of the Year
Worcester Bosch’s Greenstar Range is the latest offering from the leading boiler manufacturer.
The range is the brand's highest efficiency boiling to date, being modern A-rated boilers, they can help you save energy and money on your heating bills.
The quality and efficiency of the Greenstar Range are exactly why it was awarded CORGI’s domestic heating product of the year for multiple consecutive years.
Worcester Bosch Trustpilot Reviews
Awards from third-party consumer organisations like which are highly credible, but nothing really comes close to the honesty and reviews of everyday users of the product.
Fortunately, Worcester Bosch has some of the best customer reviews on the Trustpilot platform and is far better than any other condensing boiler manufacturer at all.
Worcester Bosch has gained an incredible number of user reviews. As of July 2024, nearly 44,000 customers left a review.
The average rating of these reviews was 4.6 out of 5 stars, quite amazing for a brand selling in such large volumes. A testament to the quality of their products and excellent customer service.
Is your current Worcester Bosch boiler experiencing problems? Check our Worcester Bosch Boiler Faults guide for common issues and potential fixes.
You can check the latest deals on Worcester Bosch boilers here, and see how the brand compared to another market leader in our Worcester Bosch vs Vaillant Boilers post.
Notable Features of Worcester Bosch Boilers:
So, what do the actual boilers offer in terms of features? Here are some of the best:
Installed with the condenseSure siphon, offering boiler frost protection
A-rated boilers - efficiency rating of up to 99.5% when operating at 30% capacity
CDi compact ideal for smaller spaces
Built-in keyless filling link making it easy to refill your system
Low energy pump limits electricity usage
10-year guarantee when purchased through Heatable
Excellent customer service and aftercare
Worcester Bosch Combi Boilers
Worcester Bosch offers many different types of boilers, but their most popular combi boilers are those from the Greenstar Range, which include the following models:
ModelAvailable kW'sPrice | ||
25, 30 | ||
25, 30 | ||
30, 35, 40, 45, 50 | ||
28, 32, 36 | ||
Worcester Bosch Si Compact | 25, 30 |
Check the latest deals on the above models here.
Learn all about combi boilers in our what is a combi boiler guide and see how Worcester Bosch fared against Baxi in our Worcester Bosch vs Baxi comparison.
Viessmann Boilers Review
Founded in 1917 and famous for its iconic German engineering and high-quality build, Viessmann has been manufacturing heating products for well over 100 years.
The Viessmann Vitodens is the brand's best-selling combi boiler, offering the perfect mix of energy efficiency, reliability, and technical brilliance.
Why Choose Viessmann?
Viessmann is a relatively new boiler brand in the UK market, but due to their high quality and technical specifications, they have soon become one of the most well-respected.
So, what are the main selling points of this boiler manufacturer?
Which? Annual Boiler Survey Performance
Viessmann did actually take a short sabbatical from the Which? Best Buy arena after 3 consecutive years, ending in 2021. From 2023 however, their relaunch of the 050 and 100 models shot them right back into Which? Wonderland.
In addition, in the most recent Which? Annual Boiler Survey they performed extremely well. They received a top score i.e. 5 out of 5 for the following:
Reliability
Customer Score
Engineer Recommendation
Build Quality
10-Year Warranty on Parts & Labour
Your boiler is arguably one of the most complex and used pieces of engineering in your home and it is something we all rely on and take for granted.
So, when your heating and hot water supply are negatively affected, it can be extremely disruptive and cause discomfort for the whole family.
Want an exact price on a new boiler? Use our boiler quote calculator (your fixed price will appear on screen).
You want the peace of mind that your boiler will be repaired and fast and that is why a warranty is so important.
Thankfully, every Viessmann boiler fitted through Heatable comes with a 10-year parts & labour warranty as standard. Not quite as good as Worcester Bosch’s guarantee, but still, it's pretty impressive.
Viessmann Trustpilot Reviews
What do Viessmann customers think of their boiler? Did their customer services and aftercare perform well? The best place to find out is by checking what they have to say on the third-party review platform Trustpilot.
Viessmann, like Worcester Bosch, have some incredible 5-star customer reviews. As of July 2024, almost 5,000 customers left a review. Some way behind Worcester on numbers, but not on quality.
The average rating of these reviews was 4.3 out of 5 stars, which reflects the brand's performance in the UK to date.
Notable Features of Viessmann Boilers:
Built-in shock arrestors – to help limit boiler noises
Combined Pressure Release Valve (PRV) & condensate pipe – less pipework, more aesthetically pleasing
Offer full-size and compact boilers
Weather compensation - cleverly compares the outside temperature to the ambient temperature in your home and adjusts your heating accordingly
Compatible with smart technology e.g. Nest Smart thermostats
Stainless Steel Inox Radial heat exchanger – more durable and last longer than the typical “aluminium” Variety
A-rated boilers - efficiency rating of up to 99.5% when operating at 30% capacity
10-year warranty when purchased through Heatable
Viessmann Combi Boilers
Viessmann offers a range of different boilers, there most popular combi boilers are as follows:
Model | Available kW’s | Price |
25, 30, 35 | ||
30, 35 | ||
Viessmann Vitodens 200-W | 26, 30, 35 |
Interested to learn about the hybrid 111? Read our full Viessmann 111 review.
Related boiler guides:
Worcester Bosch vs Viessmann Boilers
Who knows.
Both Worcester Bosch and Viessmann share some unique and similar significant advantages and, in many ways, each offers reliability, value and a superb choice for a variety of different hot water demands.
It's all down to what you want.
If you want the safety net and peace of mind that a HUGE brand offers, go for the Worcester Bosch.
Check the latest deals on Worcester Bosch boilers here.
If you aren't fussed about a brand name, and would rather have a technically (German!) better-built boiler, go for the Viessmann (Vitodens 100, or 200 - the 050 is made in Turkey).
Check the latest deals on Viessman here.
However, if we were really pushed to choose between the two, we recommend Worcester Bosch (just). Why?
Which Best Buy Award winner for 10 consecutive years
A 10-Year Guarantee not just a “warranty”
Readily available parts in the UK
Related heating/energy guides:
How to get a new boiler 👻
You may need a new boiler.
You may need it fast, and with affordable monthly payments.
You may even need it from a company with top end local engineers, with 10,000 Trust Pilot reviews to back them up. Plus a Which? Trusted Trader award for good measure.
You may need a new boiler quote from us, Heatable 😘
