Vaillant vs Worcester. Two Goliaths of the heating world go head-to-head, without a David in sight. Which is best, Bosch or Vaillant? Here's the pros, cons and everything in between.
When in the market for a new boiler, at some point it’s likely that you will stumble upon two of the UK's biggest brands – Worcester Bosch and Vaillant Boilers.
Then, you'll no doubt be left thinking...Which to choose? Which is best? Which is a Which? Best Buy? Which should you choose - Worcester Bosch or Vaillant Boilers?
In this post, we’ll be doing a deep dive and comparing the most popular boiler models from each – the Worcester Bosch Greenstar 4000 and the Vaillant EcoTec.
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First, who are Worcester Bosch, and who are Valliant Boilers?
Founded in the UK back in swinging 1962, Worcester Bosch has been a big name in the British boiler industry for decades, renowned for its high-quality build and excellent aftercare.
Check the latest deals on Worcester Bosch boilers here.
In 1992, the company joined the German-based Bosch group and for the last 10 years has won the Which? Best Buy Award.
Unboilievable.
Then, there's Vaillant.
Vaillant is another German-based company with a 140-year history as a family-run enterprise.
Das ist gut, ya?
Although the brand offers German engineering and design, all of its boiler products are manufactured in the UK. This means parts are relatively easy to source and within a relatively short time frame.
Similar to Worcester Bosch, the brand has performed well on consumer award surveys. Notably, the brand was awarded Quiet Mark accreditation by the International Eco-Award Scheme, given to the quietest products.
Worcester Bosch Greenstar vs Vaillant EcoTec
When comparing two popular boiler brands, it makes sense to make a comparison between two of their most popular boiler models.
The table below shows how two combi boilers, one from each manufacturer compare in terms of the warranty offered, power, efficiency and other important metrics.
Worcester-Bosch Greenstar 4000 | Vaillant EcoTec Plus 825 | |
Standard Warranty | 10-years through Heatable | 10-years through Heatable |
Hot Water Flow Rate | 10 Litres per min. | 9.4 Litres per min. |
ERP Rating | A | A |
Smart thermostat compatible | Yes | Yes |
LPG Compatible | Yes | Yes |
Heat Exchanger | Aluminium | Stainless Steel |
Shock Arrestor standard | No | No |
Efficiency up to | 94% | 89.4% |
Noise output (dB) | 50 | 46 |
Warranties & Aftercare Comparison
Worcester Bosch is unique in that they do not simply offer a traditional warranty, but a no-quibble guarantee.
What’s the difference, you say?
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.
You can check the latest price on Worcester Bosch boilers here.
PS You may be interested in watching our complete review of the Worcester Bosch 4000 in our Youtube video below:
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 loooong guarantee.
Vaillant also offers a 10-year warranty (not a guarantee).
However, it’s worth mentioning that they do offer a 12-year warranty on the Viessmann Vitodens 100-W (when purchased via Heatable).
Remember that your condensing boiler needs to be serviced annually and by an approved installer for the guarantees and/or warranty to remain valid.
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.
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Worcester Bosch Greenstar vs Vaillant EcoTec
Often the decision-maker when it comes to buying a new boiler – the price.
Being leading brands, neither brand is considered the cheapest, but for good reason. They are both trusted and reliable manufacturers.
In terms of price, for a Greenstar 4000 by Worcester Bosch, prices start at around £900 (that's boiler alone, without installation, flue, accessories or anything else), while a Vaillant EcoTec Plus starts at around £1100.
So, as you can see, on average a Worcester Bosch boiler is cheaper to purchase than a Vaillant boiler.
Of course, boiler prices will vary depending on the supplier you choose.
However, Heatable offers a price match guarantee, see how much your new boiler will cost today using our boiler calculator tool.
Some of the brand's most recent and popular models include 2000, 4000 and 8000, you can read our full reviews of them:
Customer Trustpilot Reviews
Awards from third-party consumer organisations are highly credible, but nothing 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 boiler manufacturer at all.
Worcester Bosch has gained an incredible number of user reviews. As of July 2024, nearly 45,000 customers left a review.
The average rating of these reviews was 4.6 out of 5 stars, quite fantastic for a brand selling in such large volumes. Agree?
Vaillant has also performed extremely well when it comes to customer feedback. As of July 2024, they have amassed over 20,000 reviews on the platform.
The average rating of Vaillant’s reviews was 4.4 (almost as good as Worcester, but not quite!), an obvious reflection of their product quality and the aftercare offered by their team.
So in terms of reviews, the brands perform remarkably similarly.
Tooshay!
Related heating/energy guides:
Size (Dimensions, not power)
Another important question all new boiler buyers commonly ask is.... will it fit in my cupboard?
A key question for those with limited space, we think you'll agree.
...jokes aside, size really does matter
Both the Worcester Bosch Greenstar and the Vaillant EcoTec are considered small boilers; on average Vaillant boilers are less wide.
However, Worcester does have the Worcester Greenstar CDi Compact, or Si Compact, designed specifically to fit into small spaces such as kitchen cupboards.
Control Options
Both boiler brands provide their models with conventional, mechanical controls with 24-hour programming and digital controls that allow you to set a 7-day schedule.
Both brands offer the ability to utilise smart thermostats too, such as Hive and Nest, allowing you to control and schedule your boiler from the comfort and convenience of your smartphone.
Other Notable Features...
Here are some of the best features offered by each of the brands.
Some of Worcester Bosch’s most popular features include:
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 is 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
Some of Vaillant’s most popular features include:
Awarded QuietMark – an international award for quiet products
ErP A-rated boiler for heat
10-year warranty (when purchased via Heatable)
Excellent customer service and aftercare
Is your Vaillant boiler experiencing some of the brand's most common fault codes? We have you covered in our F29 fault code and F62 fault code guides.
Worcester Bosch vs Vaillant Boilers: Our Verdict
Although both Worcester Bosch and Vaillant are extremely well-rated and reputable boiler brands, offering reliability, value and a superb choice for a variety of different hot water demands, we think Worcester has the edge.
Why?
On average Worcester Bosch boilers are typically slightly cheaper than Vaillant and everyone likes to save a little money.
Worcester Bosch also offers a 10-year guarantee (not just a warranty) when purchased via Heatable, while Vaillant offers a 10-year warranty as standard.
Worcester also has a brilliant range of boilers, with different power outputs and dimensions, for example, the Greenstar Compact, ideal for kitchen cupboards.
Lastly, the brand has been a Which? Best Buy Award winner for 14 years running. Truly brilliant and a feat achieved by no other boiler brand.
Here’s a summary of why you'll probably want a Worcester:
Which Best Buy Award winner for over 14 years
A 10-Year Guarantee, not just a “warranty”
Readily available parts in the UK
Want a Worcester Bosch or Vaillant boiler fitting?
If you’re aiming to get the best deal on a new Worcester or Vaillant boiler, consider getting a quote from us, here’s why:
Gas Safe installation within 24 hours.
Thousands of satisfied customers with an average score of 4.9 on Trustpilot, surpassing the market leader.
Which? Trusted Trader: Heatable is proudly recognised as a Which? Trusted Trader.
Price match guarantee: We will match any like-for-like cheaper quote.
Flexible payment options, including interest-free finance.
Up to 12-year guarantee on selected boilers.
Fixed price guarantee: No hidden costs.
Save your quote and decide later.
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To learn more about boilers, visit our advice section, check out our YouTube channel, or read customer testimonials here.
Heat Happy.
