The Viessman Vitodens 100-W is one of the best-selling gas condensing boilers on the market. It has been awarded the status of Which? Best Buy from 2017 to 2021.
Feedback from 219 Trusted Traders and 9,610 customers, covering categories such as; experience of the boiler owners, ease of servicing, fixing a common fault, availability of parts and spares, build quality, and recommendation supports the awards the Vitodens 100-W has gained so far.
Before we go into detail about the features and benefits of Viessmann’s latest 100-W boiler model, here’s some history about the Viessmann Group.
The history behind the Viessmann Group
The Viessmann Group was founded in 1917 and became a well-known locksmith company in Hof an der Saale in Germany. In 1928, the founder of the company, Johann Viessmann, decided to lay the foundations for heating solutions after being requested by many local gardeners to build a boiler for their greenhouses.
During this time, boilers were generally made from cast iron and would reach operating temperature very slowly. Viessmann’s ambition was to develop and build a new generation of steel boilers that would deliver heat faster and consume less fuel. Little did he know that this company would be passed along through three generations and become a leading provider for boilers.
Now that you know a little more about the background of Viessmann, let’s move on to the latest edition of the Viessmann family, the newly updated Vitodens 100W.
Introducing the new Vitodens 100-W
The next-generation Vitodens 100-W has become a popular solution for smaller, well-insulated homes. This newly updated condensing boiler has a wide range of benefits including a compact and lightweight design for easy installation, maintenance and future servicing, quiet operation, and high-performance ratings.
Featuring innovative smart technology and services combined with reliability and longevity, the Vitodens 100-W helps you to optimise your heating and save on energy costs.
The Vitodens 100-W is efficient, compact, quiet and affordable, the Vitodens 100-W hydrogen ready (H2 20% blend) gas condensing boiler is the most popular solution for smaller and well-insulated homes, and now with its added integrated WiFi control platform, this boiler has now become even more efficient. According to Viessmann, commissioning and servicing is now said to be a lot easier; monitoring and adjusting your boiler remotely with no third-party controls is now doable and its newly updated mechanical design has reduced the number of spare parts required during a routine check by a massive 50%, this is great news for your Gas Safe Engineer.
The Vitodens 100-W is available as a system boiler in the following sizes: 11kW, 19kW, 25kW, and 32kW, and as a combi boiler in 26kW, 30kW, and 32kW.
Key Information:
Manufacturer | Viessmann |
Model | Vitodens 100-W Gas Boiler |
Condensing | Yes |
Efficiency Rating | 94% |
Energy Efficiency Class | A-Rated |
LPG Compatible | Yes |
Warranty | Up to 10-year comprehensive when installed by a Viessmann installer |
Weight | 38kg |
Dimension | H:700mm x W:400mm x D:350mm |
The latest Viessmann Vitodens 100-W has a range of great features:
Viessmann Vitodens 100-W key features
- High-quality stainless steel Inox-Radial heat exchanger
- Environmentally responsible MatriX-Plus cylinder burner which extends the boiler’s service life and reduces CO2 and NOx emissions
- Lambda Pro automatic combustion control for maximum efficiency at all times
- Backlit LCD touch screen display
- Integrated Wi-Fi
- Pressure release valve and condensate combined for easy installation
- Compact design and low weight for installation in a standard kitchen cupboard
- Quiet operation with low fan speed
- Low CO2 emissions for reduced environmental impact
- Modulation range up to 1:10
- Constant temperature control and weather compensated operation (an outside temperature sensor is available for weather compensation)
- Ready for 20% hydrogen mix in the gas supply
- Up to 10 years extended warranty available
- LPG conversion kit available
- Compatible with Viessmann’s Vitoguide software, and ViStart and ViCare app
- 10-year warranty available on heat exchanger
- Viessmann boilers, kits, and parts are available at all Plumbase stores across the UK.
The new and improved Vitodens 100-W, launched April 2021, is now fitted with integrated Wi-Fi, making this boiler fully compatible with the battery-powered, RF-connected ViCare Thermostat. This also means that the boiler itself can be controlled using the boiler’s large seven-inch colour touchscreen, as well as the ViCare app, which can be downloaded on a smartphone or tablet.
The ViCare app provides the Vitodens 100-W with the following functionality:
- Information on the current operating status
- Quick adjustments to the heating system
- Time programmes for heating and hot water, by zone
- Allows the system to be remotely monitored by your local heating engineer
What is the difference between the original and the new Vitodens 100-W?
The Vitodens 100-W boiler is known for its reliability and efficiency, even before the latest 2021 update. However, in the latest model, Viessmann has made some beneficial upgrades to increase its efficiency even more.
The 2021 Vitodens 100-W model is enhanced by the new MatriX-Plus burner and new Lambda Pro automatic combustion control. These technologies ensure low fuel consumption with low NOx and CO2 emissions. This newest model also has an increased modulation range, with the boiler now modulating 1:10 (32kW).
The Lambda Pro automatic combustion control ensures reliable and clean operation even when the gas quality fluctuates. It does this by detecting and adjusting to the gas type. In addition to this, this boiler offers future-proof ability with reliable and efficient compatibility if the seemingly possible happens and the UK gas grid supplies a blend composed of 80% natural gas and 20% hydrogen.
In addition to this, Viessmann boilers utilise a stainless steel Inox-Radial heat exchanger in their boilers, rather than an aluminium heat exchanger. This will increase the boilers’ efficiency, reliability, durability, and corrosion resistance. You also receive a 10-year warranty on the heat exchanger for extra peace of mind.
Alternatives to the Vitodens 100-W
When it comes to buying a new boiler, there are many factors you have to consider. These include the size of your home as well as the space in your home, your existing boiler, the current flue positioning, and the demands of your home.
Now, we know that after reading all the amazing features the Viessmann 100W seems to be an all-singing, all-dancing condensing boiler. However, it is said to cost around £2,500 for the boiler and installation, which to many can be costly. Here at Warmzilla, we like to offer you alternatives that are similar in performance and features but could be more cost-efficient.
One of these being the Worcester Bosch Greenstar 8000 Lifestyle range. Since launching in May 2019, they have become one of the more popular boiler choices in the U.K. This is because of their modern, sleek design and powerful output range.
Worcester Bosch Greenstar Life 8000
Key Features:
- Outputs ranging from 30kw to 50kw
- Lesser weight than the famous Cdi Classic
- Installation, servicing, and maintenance made easier
- Wireless connectivity with the Bosch EasyControl
- Same pipe connections, flue, and fixing points as the CDi Classic enabling an easy swap

Worcester Bosch Greenstar Style 8000
Key Features:
- Outputs ranging from 30kw to 50kw
- Wireless connectivity with the Bosch EasyControl
- Stunning design-led aesthetics
- Precision engineering and industry-leading heating and hot water performance
- Full-colour text display for simple diagnostics
- Innovative boiler control display codes
- Choose from 2 stunning high gloss colours – Black or White
Worcester Bosch currently holds the Royal Warrant to supply heating to the Royal Family and has won the Which? Best Buy award for their range of boilers for the last ten years. This prestigious award is judged on reliability, build quality, recommendation, and customer score. This is why the Worcester Bosch Greenstar Life and Style 8000’s are the perfect alternatives to the Vitodens 100-W. Below is a comparison table to show you the performance, efficiency rating, output, and price of both the Worcester Bosch Life 8000 and the Style 8000, to help you decide on the best boiler for you.
If you are interested in knowing more about the Worcester Bosch Lifestyle range, we have a blog covering everything you need to know.
Comparison Table
Manufacturer | Worcester Bosch | Worcester Bosch | Viessmann |
Model | Greenstar Life 8000 (30kW) | Greenstar Style 8000 (30kW) | Vitodens 100-W (2021) |
Condensing | Yes | Yes | Yes |
Efficiency Rating | 94% | 94% | 94% |
Energy Efficiency Class | A-Rated | A-Rated | A-Rated |
LPG Compatible | Yes | Yes | Yes |
Warranty | 12 years | 12 years | Up to 10-year comprehensive when installed by a Viessmann installer |
Weight | 62kg | 59kg | 38kg |
Dimensions (mm) (H x W x D) | 780 x 440 x 365 | 780 x 440 x 365 | 700 x 400 x 350 |
Price *(boiler only) | £1,222.80* | £1,318.80* | £1,270.80* |
Controls | Button display | Touchscreen display | Touchscreen display |
It is important to note that the prices may vary for each boiler model, dependant on the merchants.
Summary
The Viessmann Vitodens 100-W condensing boiler is a great replacement for older boilers. If you are into your high-tech gadgets, you may be more inclined to look into the newest 2021 edition, as it has plenty of great features including a touch screen display. As you can see in the comparison table, the Vitodens 100-W is also slightly less expensive and smaller than the Worcester Bosch Greenstar Style 30kW, with little difference between the two regarding performance and features.
However, if you are looking for a new boiler that fits with the aesthetics of your home, the Style 8000 comes in two colours, either black or white. It also comes with 2 years extra warranty.
It is also important to bear in mind that although Viessmann parts are distributed across the UK, they can be a little harder to get hold of because the Viessmann HQ is in Germany, whereas Worcester Bosch parts are a lot easier to get hold of. Worcester Bosch have also awarded the Which? Best Buy award for their aftercare services, which is second to none. A Trustpilot score of 4.6 out of 5 and over 26k reviews supports this. Therefore, if you were to purchase a boiler from Worcester Bosch, you would have that added peace of mind.
To conclude, it is obvious that the new Vitodens 100-W is a great condensing boiler for your home, however, there are alternative boilers that offers a similar performance if the Vitodens 100-W is not your preference.
Viessmann is also launching the Vitodens 111-W wall-mounted combi boiler, intended for a family home with a high demand for hot water and central heating. The Vitodens 111-W features a cylinder loading system and a 46 litre integrated stainless steel storage tank, allowing it to provide a flow rate of up to 181l in 10 minutes. All models are hydrogen-ready, certified for a 20% hydrogen blend.
*Average boiler prices were taken from an online heating supplier on the 3rd of February 2022. Prices are for the boiler alone and may be subject to change.