Worcester Bosch vs Vaillant Boilers
Although there are a huge number of boiler manufacturers out there, the battle for ‘Top Boiler Brand’ in the UK often comes down to just two names – Worcester Bosch and Vaillant.
Both brands are household names in the UK with excellent reputations, consistent high customer satisfaction scores, and independently-verified top quality products.
Deciding which of the two brands to choose when purchasing a new boiler is not easy so this guide is here to compare the two market leaders and to help you to choose the right manufacturer for you.
In this guide, we discuss:
- who is Worcester Bosch?
- who is Vaillant?
- what types of boilers do Worcester Bosch and Vaillant manufacture?
- Worcester Bosch and Vaillant: head-to-head
- Worcester Bosch Greenstar 12Ri Boiler review
- Vaillant ecoTEC plus 825 Boiler review
- who wins the battle of the flagship boilers?
- Worcester Bosch boilers: an overview
- Vaillant boilers: an overview
- repairs and warranties
- how to get new boiler installation quotes
Who is Worcester Bosch?
Established in 1962, Worcester Bosch is a UK-based company providing solar water heating systems, gas boilers, oil boilers, heat pumps and hot water cylinders to homes and organisations all over the world.
The brand frequently wins the Which? Best Buy Awards with their outstanding boilers and they even supply the Sandringham Estate.
A recent Which? survey rated Worcester Bosch boilers five out of five for overall customer score and engineer recommendations as well as for reliability and the availability of parts.
Who is Vaillant?
Vaillant is a German company established more than 140 years ago and it currently supplies customers in 60 countries.
The business offers a cohesive blend of German design and UK-based manufacturing – all parts are easily sourced for installers when a repair is needed and all of their boilers comply with UK requirements.
Vaillant also maintains very high standards of customer satisfaction with a 4.7 out of 5 score on TrustPilot based on more than 10,759 reviews at the time of writing.
Managing Director of Vaillant UK and Ireland Klaus Jesse says that he and his team are dedicated to providing industry-leading customer service.
In this they are successful because the brand’s UK sales is driven by customer referrals and word-of-mouth reviews.
What types of boilers do Worcester Bosch and Vaillant manufacture?
Both Worcester Bosch and Vaillant produce a wide range of different boiler types suitable for different homes and households.
These boiler types are:
Combi boilers
Combi boilers are the most common type of boilers installed in British homes.
Almost every new-build house and flat will come with a combi boiler installed and most homeowners are upgrading to this type of boiler over time.
The combi boiler is the most compact type, ideal for both small and medium-sized houses and flats, consisting of a single unit which often can fit in a cupboard or on a surface.
They take less time to install and they break down less than other types of boilers.
Regular boilers
Conventional boilers are a slightly older type of boiler and they are most often found in larger properties where there is more need for hot water around the clock.
These boilers feature a cold water storage tank which is linked to a hot water cylinder through which the water is transferred to both the taps and radiators in your home.
Although regular boilers cost around the same as a combi boiler, the installation costs are often higher because the pipework and heating system is more complicated.
System boilers
Owners of larger properties often select a system boiler to ensure a constant supply of hot water to two or more bathrooms.
With a system boiler, there is no need for a cold water tank as the hot water cylinder stores and heats the water ready for distribution to your taps and radiators.
System boilers are also popular with homeowners as you can use two or more taps around your property at the same time with no reduction in water pressure.
Worcester Bosch and Vaillant head-to-head
There are hundreds of different boiler models available on the market today, making it feel to many like it’s almost impossible to choose the right one for your home.
We are dedicated to helping our readers make an informed decision when choosing their new combi boiler.
With that in mind, we have designed a system unique to our site which ranks boilers according to energy efficiency rating, warranty, output and price.
Looking in-depth at these metrics should give you a better idea of the right boiler type for you and your home.
Before we compare Worcester Bosch and Vaillant in more depth, we will first look at how the two compare across their entire ranges.
| Manufacturer | Average price | Energy efficiency | HomeSage score |
| Worcester Bosch | £1,391 | 93.39% | 90.25% |
| Vaillant | £1,189 | 90.43% | 83.85% |
Vaillant is clearly the winner here when it comes to price but Worcester Bosch takes the lead on both energy efficiency and the overall HomeSage score.
However, with just a 3% difference in average energy efficiency, the money saved on energy bills over time with Worcester Bosch boilers is negligible in comparison with the huge £202 difference in average price between the boilers.
To look more thoroughly into the range, it is best to compare the two best HomeSage-rated gas-powered combi boilers – one from each manufacturer.
These are:
- Worcester Bosch Greenstar 12Ri Boiler
- Vaillant ecoTEC plus 825 Boiler
Both boilers are ideal for smaller houses and flats.
Worcester Bosch Greenstar 12Ri Boiler review
| Make and Model Name | Efficiency Rating | Parts and Labour Warranty | Output kW | Price from | TOTAL |
| Worcester Bosch Greenstar 12Ri Boiler | 92.00% | 60 | 12 | £800 | 79.57% |
One of the most striking features of the Worcester Bosch Ri range is the small size. All of the boilers in the range are the same size: 600mm x 390mm x 270mm.
This is more than small enough to fit inside most kitchen cupboards allowing the boiler to be tucked away out of sight.
The 12Ri is so named in reference to the central heating output of the boiler – in this case, 12kw.
The boiler is incredibly energy efficient with the heat exchanger constructed from cast aluminium and silicon ensuring no energy waste through the boiler flue.
The Greenstar Ri is also notably low in NOx and CO2 emissions making it an environmentally sound option.
Meanwhile, the boiler benefits from simple control knobs and a basic, user-friendly display.
The stylish display allows homeowners to easily set their desired temperature and adjust it at will to ensure optimal heating all year round.
Vaillant ecoTEC plus 825 Boiler review
| Make and Model Name | Efficiency Rating | Parts and Labour Warranty | Output kW | Price from | TOTAL |
| Vaillant ecoTEC plus 825 Boiler | 94.00% | 60 | 20.4 | £1,130 | 79.57% |
The Vaillant ecoTEC Plus 825 offers a slightly larger central heating output of 20.4kw, ideal for small properties and flats but also able to heat properties up to 3 bedrooms with 1 bathroom.
The boiler measures 720 x 440 x 338mm making it a little larger than the Worcester Bosch and meaning that it may not be as suitable for installing inside a kitchen cupboard.
However, the ecoTEC Plus is still a sleek and compact boiler with a simple control panel installed under the front flap for ease of use.
The controls are user friendly, allowing you to quickly switch off the boiler or lower the temperature.
This Vaillant model also offers a wide range of optional controls alongside the boiler for even better handling of the output.
The boiler can also be used with a Smart Thermostat which allows the user to operate it from their smartphone or tablet.
The Vaillant ecoTEC Plus 825 is a high-performance, energy efficient boiler with an ErP rating of 89.3% – an A grade for efficiency.
Additionally, the ecoTEC Plus range has been awarded the QuietMark as a design with reduced noise production.
Who wins the battle of the flagship boilers?
While it is an incredibly close race between Worcester Bosch and Vaillant, the Vaillant boiler range edges the competition very slightly, thanks to its stainless steel heat exchanger which provides a more robust system designed to last.
Vaillant is also more popular with engineers who tend to agree that their boilers are easier to install, and simpler to repair.
Installers also highly rate the simple control panel allowing repairs and adjustments to be made quickly over the phone.
Worcester Bosch boilers
At the time of writing, Worcester Bosch has a range of 49 gas-powered boilers.
These average out to around £1,391 across the entire range of combi, regular and system boilers.
Worcester Bosch top 5 combi boilers
Of the 21 gas-powered combi boilers in Worcester Bosh’s range, the top scored 5 are:
| Make and Model Name | Efficiency Rating | Parts and Labour Warranty | Output kW | Price from | TOTAL |
| Worcester Bosch 2000 25kw Boiler | 93.00% | 60 | 9 | £760 | 91.89% |
| Worcester Bosch 2000 30kw Boiler | 93.00% | 60 | 10.8 | £870 | 91.62% |
| Worcester Bosch Greenstar 25i Boiler | 94.00% | 60 | 9 | £955 | 91.41% |
| Worcester Bosch Greenstar 28CDi Compact Boiler | 94.00% | 60 | 10 | £980 | 91.35% |
| Worcester Bosch Greenstar 25Si Compact Boiler | 94.00% | 60 | 8.9 | £1,055 | 91.16% |
Worcester Bosch top 5 regular boilers
Worcester Bosh have 14 gas-powered regular boilers in their range, boasting an average HomeSage rating of 90.44%.
The top 5 are:
| Make and Model Name | Efficiency Rating | Parts and Labour Warranty | Output kW | Price from | TOTAL |
| Worcester Bosch Greenstar 12Ri Boiler | 92.00% | 60 | 12 | £800 | 91.79% |
| Worcester Bosch Greenstar 15Ri Boiler | 92.00% | 60 | 15 | £825 | 91.72% |
| Worcester Bosch Greenstar 18Ri Boiler | 92.00% | 60 | 18 | £880 | 91.59% |
| Worcester Bosch Greenstar 24Ri Boiler | 92.00% | 60 | 24 | £935 | 91.45% |
| Worcester Bosch Greenstar 21Ri Boiler | 92.00% | 60 | 21 | £975 | 91.36% |
Worcester Bosch top 5 system boilers
All of the top 5 scored gas-powered system boilers in Worcester Bosch’s range are from the renowned Greenstar Ri range.
They are:
| Make and Model Name | Efficiency Rating | Parts and Labour Warranty | Output kW | Price from | TOTAL |
| Worcester Bosch Greenstar 9i Boiler | 93.00% | 60 | 9.2 | £880 | 91.59% |
| Worcester Bosch Greenstar 12i Boiler | 94.00% | 60 | 12.2 | £890 | 91.57% |
| Worcester Bosch Greenstar 15i Boiler | 94.00% | 60 | 15.3 | £950 | 91.42% |
| Worcester Bosch Greenstar 18i Boiler | 94.00% | 60 | 18.4 | £1,005 | 91.29% |
| Worcester Bosch Greenstar 21i Boiler | 94.00% | 60 | 21.6 | £1,015 | 91.26% |
Vaillant boilers
Vaillant’s range of gas-powered boilers currently stands at 49 models, and has an average price of £1,189.
Here we list the top models in their ranges of combi, regular and system boilers.
Vaillant top 5 combi boilers
Vaillant has 14 gas-powered system boilers in their range, boasting an average HomeSage rating of 84.12%
The top 5 are:
| Make and Model Name | Efficiency Rating | Parts and Labour Warranty | Output kW | Price from | TOTAL |
| Vaillant ecoTEC exclusive Green iQ 627 Boiler | 94.00% | 84 | 27 | £1,080 | 88.85% |
| Vaillant EcoTEC Plus 64 Boiler | 94.00% | 60 | 64 | £1,470 | 86.23% |
| Vaillant Home 25 Boiler | 89.40% | 24 | 25 | £810 | 85.34% |
| Vaillant ecoTec plus 624 Boiler | 89.40% | 60 | 24 | £985 | 84.91% |
| Vaillant ecoTec plus 630 Boiler | 89.40% | 60 | 30 | £1,125 | 84.57% |
Vaillant top 5 regular boilers
Four out of the five top scored gas-powered regular boilers in the Vaillant range are from the ecoTEC range.
There are 14 regular boilers in the range, and the top 5 are:
| Make and Model Name | Efficiency Rating | Parts and Labour Warranty | Output kW | Price from | TOTAL |
| Vaillant ecoTEC plus 418 Boiler | 89.30% | 60 | 18 | £860 | 87.72% |
| Vaillant ecoTEC plus 415 15 Boiler | 88.70% | 60 | 15 | £775 | 85.43% |
| Vaillant ecoTEC plus 412 Boiler | 89.30% | 60 | 12 | £810 | 85.34% |
| Vaillant Home 30 Boiler | 89.40% | 24 | 30 | £905 | 85.11% |
| Vaillant ecoTEC plus 424 24 Boiler | 89.30% | 60 | 24 | £955 | 84.99% |
Vaillant top 5 system boilers
Vaillant has 14 gas-powered system boilers in their range, with the top 5 being:
| Make and Model Name | Efficiency Rating | Parts and Labour Warranty | Output kW | Price from | TOTAL |
| Vaillant ecoTEC exclusive Green iQ 627 Boiler | 94.00% | 84 | 27 | £1,080 | 88.85% |
| Vaillant EcoTEC Plus 64 Boiler | 94.00% | 60 | 64 | £1,470 | 86.23% |
| Vaillant Home 25 Boiler | 89.40% | 24 | 25 | £810 | 85.34% |
| Vaillant ecoTec plus 624 Boiler | 89.40% | 60 | 24 | £985 | 84.91% |
| Vaillant ecoTec plus 630 Boiler | 89.40% | 60 | 30 | £1,125 | 84.57% |
Repairs and Warranties
Both Worcester Bosch and Vaillant have at least a five year warranty included as standard with their boilers.
They both employ UK-based engineers available to help customers over the phone and in the home.
In the rare event of a breakdown, parts are readily available in the UK meaning a minimal waiting time when a repair is needed.
Both manufacturers also offer extended warranties of up to 10 years.
For Vaillant, there is a charge for an extended warranty whilst Worcester Bosch offers this for free.
To qualify for Worcester Bosch’s extended warranty, homeowners must agree to a yearly service check using pre-approved engineers and parts.
Get new boiler installation quotes
Choosing the right make and type of boiler for your home is only the first step to getting a boiler installed that works for you and saves you money.
Installation charges can add significantly to the overall cost of a new boiler.
Plus, if the installation is not done correctly, you may find that your boiler does not work as efficiently as you would like.
The best way to find the right boiler and installation process for your home is to speak with a few Gas Safe registered installers.
They can give you a quote based on what you want your boiler to do, how you want it to work, and how much energy you are looking to save.
We can help you to do this without the fuss!
Simply fill out the form on our website.
We’ll put you in touch with 3 or 4 registered engineers who will provide you with a free, no-obligation quote and the information you need to help you to make the right decision for you.
Our service is free and, if you decide not to go with any of the quotes we give you there is no penalty, so you’ve nothing to lose!
