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Viessmann Vitodens 100-W Review
Updated April 2021
Price (Installed): From £2500 (inc. VAT)
The Viessmann Vitodens 100-W is Viessmann’s best-selling gas condensing boiler, one of the most popular boilers we install and has been awarded a Which? Best Buy three years in a row.
For 2021, the Viessmann Vitodens 100-W has been updated with all new features.
In this review, we have taken a look at the new 2021 version of this boiler in detail and offered our thoughts.
Interested in the Viessmann Vitodens 100-W?
Viessmann Vitodens 100-W Technical Specification
| 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 warranty when installed by a Viessmann trained installer |
| Weight | 38kg |
| Dimensions | 700mm (Height) x 400mm (Width) x 350mm (Depth) |
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
| kW Size | Flow Rate |
| 26kW | 10 l/min |
| 30kW | 12 l/min |
| 32kW | 14.5 l/min |
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
- 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 year extended warranty available
- LPG conversion kit available
- Compatible with Viessmann’s Vitoguide software, and ViStart and ViCare app
Interested in the Viessmann Vitodens 100-W?
Our thoughts on the Viessmann Vitodens 100-W
Which? Best Buy
The Viessmann Vitodens 100-W has surged in popularity since first being awarded Which? Best Buy status in 2017.
The Vitodens 100-W’s Best Buy status was first awarded based on feedback from 219 registered Which? Trusted Traders heating engineers and 9,610 domestic customers. This feedback covered the experiences of the boiler owners and the views of the installers in regard to the ease of servicing, fixing a common fault, availability of parts and spares, build quality and recommendations.
Having also received Which? Best Buy status in 2018 and 2019, the boiler has been noted for its reliability each time.
Integrated Wi-Fi
Launched in April 2021, the new Vitodens 100-W notably now comes with integrated Wi-Fi. This along with the 100-W’s new control platform makes commissioning and servicing the boiler easier. From an engineer’s perspective, this means that they are now able to monitor and make adjustments to customers’ boilers remotely using the Vitoguide software. This shortens services processes and improves customer service by showing the engineer the status of customers’ systems at a glance. Here, they are able to see fault messages instantly and respond to any issues promptly.
For the engineer, the compatibility with Vitoguide also makes commissioning the boiler easier and provides a step-by-step guide covering time programmes, heating circuits, heating curves, DHW and the circulation pump.
For the end-user, the integrated Wi-Fi means that the Vitodens 100-W is now fully compatible with the battery-powered, RF-connected ViCare Thermostat. This means that the boiler can not only be controlled using the boiler’s large seven-inch colour touchscreen, it can also be controlled using this device whilst at the property and not only that, it can also be controlled wherever you are in the world using the ViCare app on a smartphone or tablet – all without the need for third-party controls.
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
Reliability and efficiency
Reliability and efficiency continue to be two of the standout qualities of the Vitodens 100-W. This is enhanced by the new MatriX-Plus burner and new Lambda Pro automatic combustion control in the 2021 Vitodens 100-W range. These technologies ensure low fuel consumption with low NOx and CO2 emissions.
New for 2021 is the Vitodens 100-W’s increased modulation range, with the boiler now modulating 1:10 (32kW).
Whilst the new Lambda Pro automatic combustion control ensures reliable and clean operation even when the gas quality fluctuates by detecting and adjusting to the gas type. In addition to this, it offers future-proof ability with reliable and efficient compatibility if the seemingly possible happens and the UK gas grid supplies a blend comprised of 80% natural gas and 20% hydrogen.
10-year comprehensive warranty
The reliability of this boiler is then backed up by the up to 10-year comprehensive warranty available.
For 2021, the mechanical design of the Vitodens 100-W has reduced the number of spare parts needed for routine maintenance by about 50%. This means routine maintenance and servicing is made easier.
Whilst with a 94% efficiency rating, this boiler is one of the highest efficiency condensing gas boilers available to purchase in the UK currently. It also sits at an attractive price point compared to other boilers available in the UK. However, this is not a budget boiler option.
Viessmann is one of the most technologically advanced boilers manufacturers in the world and the Vitodens 100-W benefits from the following as a result:
- 94% efficiency
- Lightweight construction
- Compact in size
- Very quiet operation, with noise levels of just 35dB
A major contributor to Viessmann being able to keep the cost of the Vitodens 100-W down is the fact that the entire boiler and all of its components are manufactured at Viessmann’s headquarters in Allendorf, Germany. A centre of excellence, at their Allendorf site, Viessmann has focused on the efficiency and innovation of their gas-fired wall-mounted condensing boilers. It is here that they have strived to improve their product quality and performance, recognising their past mistakes and issues with obtaining parts, and have worked hard to rectify this.
Viessmann’s hard work has paid off and this shows with the quality of the Vitodens 100-W.
Parts and service availability
As mentioned above, one of the earliest complaints Viessmann boilers faced was the non-availability of parts. This is something which has been rectified by investing in their UK headquarters in Telford, Shropshire. Now all Viessmann boilers, kits and parts are available at all Plumbases stores across the UK.
Whilst in the rare event of a problem, a Viessmann engineer can be at your doorstep within 24 – 48 hours.
Innovative technology
Inox-Radial stainless steel heat exchanger
Unlike many other boiler manufacturers supplying boilers to the UK market, Viessmann utilises a stainless steel heat exchanger in their boilers rather than one constructed from aluminium. A patented product called an Inox-Radial stainless steel heat exchanger, this is manufactured in-house by Viessmann and offers the following benefits:
- Constructed from Inox, the highest grade of stainless steel available
- Increased efficiency, reliability, durability and corrosion resistance compared to aluminium
- The technology is a major contributor to the 94% efficiency rating achieved by the boiler
- 10-year warranty
CFS (Combined Flue System)
If you are looking at renovating or modernising your property, the Viessmann Vitodens 100-W condensing boiler makes for an ideal replacement for older boiler systems. Using a Viessmann CFS (combined flue system) means multiple boiler flues can be routed to exit from one exit point, whether it’s through the roof or through the wall.
Combined Condensate & PRV
Viessmann’s entire boiler range also has combined PRV (pressure relief valve) and condensate connections that can also be routed into the CFS, and one single drain at the base of the system is all that is required to remove the condensate, without the need of ugly pipes protruding through the external walls.
For more detail on this useful aspect of your heating system, please read our ‘What is a condensate pipe?‘ blog post.
Our verdict on the Viessmann Vitodens 100-W
On top of winning “Which? Best Buy” awards, pumping out a whopping efficiency of 94%, dominating the European market and having our engineers singing its praises, our verdict is pretty straightforward.
With the futureproof technologies added to this already highly popular boiler, you simply cannot go wrong with choosing the Vitodens 100-W in 2021
What’s more, if you get the boiler installed by a Viessmann Trained Installer like Boilerhut, you will not only have your boiler installed to the highest standards, you will also benefit from an extended 10-year warranty.
As the internal components are built to last, choose the Vitodens 100-W and we expect you to be able to enjoy trouble-free winters for the next decade at the very minimum.
Interested in the Viessmann Vitodens 100-W?
Boilerhut Limited
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In the Republic of Ireland who are the recommended installer of the Vitodens 100W.
Hi Joseph,
Thanks for your comment. I have sent an email to you with more information.
Hi. Great article thanks. Just wanted to know, do you have to pay extra for the extended 10yr Warranty, when fitted by approved Viessmann installers like yourselves please?
Thanks.
Hi Jay Kay,
Apologies for the late reply. You don’t have to pay extra for 10 year warranties on the 100-W and 111-W models. The 050-W has 7 years warranty on the boiler and 10 years on the heat exchanger, but the boiler warranty may be extended to 10 years at a nominal cost.
Best regards,
Ash
Boilerhut Ltd
Is it a full warranty, i.e. parts & labour? Or just parts? I remember the likes of Hotpoint advertising long warranties, but they’re not what they appear and usually involve a £££ cost to take advantage of.
Hi Craig. It’s definitely parts & labour. And 10 years on the heat exchanger across Viessmann’s entire range.
You can find more information at this link: https://professionals.viessmann.co.uk/en/residential-buildings/viessmann-warranties.html
I would also like to know who installs vitodens 100w in the ROI. I live in Dublin.
Hi John,
I’ve emailed you with the information. Please check your inbox.
Best regards,
Ash
Boilerhut Ltd
Can the 100w link to a Web app and mobile phone..?
Hi Jim,
Thanks for your comment. Yes, the 100-w can link to a web app and mobile phone.
Viessmann’s recommendation on the 100-W model is a Tado Smart Thermostat.
However, Boilerhut recommend a Nest 3rd Generation Smart Learning Thermostat instead.
Best regards,
Ash
Boilerhut Ltd
Can you pls advice who can install in in Ondon, I live at Walthamstow E17 and your installation fees. Also pls advance which boiler to purchase, I live in a 2 bed flat, 1 toilet, kitchen and sitting room.
Hi Kim,
Thanks for your comment. We’re a national installer of Viessmann boilers. For your property size, we will recommend either a Vitodens 050-W 29kw, or a Vitodens 100-W 30kw. I’ve sent you an email with more information.
Best regards,
Ash
Boilerhut Ltd
Hi,
I will be replacing my 20year old Worcester boiler within the next 3 months and I was wondering which Viessmann boilers I should consider. I live in a three bed semi, one bath with shower over it, lounge, dining, kitchen and decent sized hallway. How long is a typical installation and would you fit new rads in some rooms?
Many thanks,
Peter.
Hi Peter,
Below are the answers to your questions:
1. I will be replacing my 20year old Worcester boiler within the next 3 months and I was wondering which Viessmann boilers I should consider. I live in a three bed semi, one bath with shower over it, lounge, dining, kitchen and decent sized hallway.
After having a quick chat with one of our in-house heating experts, we’d suggest either a Viessmann Vitodens 050-W 29kW or the Viessmann Vitodens 100-W 30kW model.
2. How long is a typical installation and would you fit new rads in some rooms?
A typical combi to combi swap can take 1 day. Converting to combi from different versions can take between 1-2 days or more depending on how much work needs to be done. We can fit new rads, no issues.
You can get a free, no obligation online boiler quote here from our homepage: https://boilerhut.co.uk/
Best regards,
Ash
Boilerhut Ltd
I am currently having building works done and need my old valiant boiler moving so have decided instead to get a new one installed. The builder has recommended a Viessmann Vitodens 100w system boiler. I also have a mega flow system alongside my boiler which will remain. After works my property will be 3 bathrooms 5/6 bedrooms. Do you think this Viessmann boiler will be sufficient? Thanks for your help.
Hi Debbie,
Thanks very much for the enquiry! The Viessmann Vitodens 100-W boiler may very well be the best choice as it’s considered top of the market right now. However for a more thorough answer, we would also need to know the size of the boiler that you’re considering.
If you give us a call on 02920 099898 and speak to one of our heating experts, we’ll be happy to point you in the right direction!
Kind Regards,
Bryn
Boilerhut Ltd
Please furnish me with a list of your recommended installers in dublin, Ireland.
Is the Vitodens 200 just more powerful than the 100? Why would you buy one over the other?
Thanks
Bk
Hi Barry!
Unfortunately we don’t carry out any of our installations in that area.
With regards to which boiler is better between the Vitodens 200-W and the Vitodens 100-W, it very much depends on factors like the size of your property, and how many bathrooms you have etc.
For instance, the 200-W is a powerful, flexible boiler that is perfect for larger detached and semi-detached homes, whereas the 100-W may be a better option for smaller, well-insulated homes. However, you will still need to take into account things like water demand, including how many people would be using the supply at any one time.
For more reliable and useful information, read our blogs on the following topics:
What size boiler do I need?
Which Boiler is best
Viessmann Vitodens 200-W review
We hope this answers your question, and thank you very much for contacting us!
Kind regards,
Bryn
Boilerhut Ltd
I am doing a rear extension on my flat, ground floor. Will have 2 bedrooms and 2bathrooms. I have been considering Viessmann Vitodens 100-w 26kw. Would that be efficient? Maximum people in the flat is 3.
Hi Elena!
The Viessmann Vitodens 100-W 26kw is an excellent boiler with many benefits.
However, your flow rate would be too low with the 26kW version. If we consider your user profile with up to 3 people, 2 bedrooms and 2 bathrooms, you’d be much better off with either the Viessmann Vitodens 100-W 35kW, or the Viessmann Vitodens 050-W 35kW.
For a digestible breakdown of which boiler is right for you, take a look at the following article:
Which boiler is best?
Alternatively, you can visit our website for a FREE, no-obligation quote or call us on 02920 099898 and speak to one of our trusted heating experts for support and advice.
Kind Regards,
Bryn
Boilerhut Ltd
I need a new boiler for a three bedroom Terraced house
My previous boiler was very very noisy and my bedroom is directly above the kitchen It has been like sleeping on the grounds of Heathrow airport with jumbo jets
Can you you guarantee me a quiet boiler pse and how early can you install in M45 pse
I ve a 3 year old grand daughter m the house is very cold I ve sleepless
Ive insurance with British Gas the last visit the engineer said it news changing no longer ve the parts for the current boiler
Can’t afford British Gas prices for the boilers they supply it’s far beyond my pocket
Hi Julliana,
Thanks very much for the enquiry.
The good news is that Viessmann has always taken customer feedback very seriously, and have continued to improve their boiler range based on this feedback – including the noise of the boiler itself.
Based on the situation you’ve described, we firmly believe that many of the boilers in Viessmann’s own range would serve you well. Reviews of the Viessmann range can also be found using the following link: https://www.reviews.co.uk/company-reviews/store/viessmann-co-uk
However, you can also visit our website for a free, no-obligation quote which will break down your best options. Alternatively, you can speak to one of our in-house heating experts for further support and advice.
Kind Regards,
Bryn
Boilerhut Ltd
I find the boiler calculator doesn’t suit my situation. I have 2 bed semi property with old 18kw system boiler, I bathroom, 7 radiators but also wet underfloor heating. The current 18kw seems to heat everything fine but I have had suggestions of going lower as new boilers more efficient or going higher as the underfloor heating was added since it was originally specified. Looking at the Viesmann Vitodens 100 but which Kw?
thank you
Hi Gary,
Thanks for the good question!
If you’re ever unsure about which boiler is right for you, the best thing you can ever do is get professional, reliable advice directly from an expert. For further help and information you can call us on 02920 099 898, where one of our team members will be happy to discuss your options with you. Hope this helps!
Kind Regards,
The Boilerhut Team
In the Republic of Ireland who are the recommended installer of the Vitodens 100W. Thank You
Hi there,
Thanks very much for the enquiry.
Unfortunately we don’t operate in the Republic of Ireland. However, we recommend for your research that you choose an installer with a similarly strong relationship with Viessmann as Boilerhut. That way you’ll still be able to enjoy all the benefits that come with such an arrangement.
We hope this helps!
Kind Regards,
The Boilerhut Team
Does Viessmann now manufacture a room thermostat compatible with the Vitodens 100-W?
Thanks.
Do boilerhut offer complete system installs? I want to change from a traditional system over to a combi set up – preferably viessmann 100 30kw. My pipes all need replacing and re-designing (some in concrete floors + microbore) also want 9 new rads and lager gas pipe coming into boiler. Cheers John
I have a 3 bedroom terraced property with 8 radiators and 1 shower. The shower is used around 5 times a day and sometimes the kitchen sink hot water tap is used at the same time as the shower. Which kWh boiler would I need if I wanted a viessmanns 100w?
I’ve recently had the 26Kw Vitodens 100-W installed and was disconcerted to find the radiators cycling between 100% and zero. The wireless thermostat, is located in the hall (as recommended by the installer) and is set to 21.0 degrees and the heating temperature on the boiler is set at 70.0 degrees by the installer. The installer said this behaviour was normal but to me it doesn’t seem efficient and I can’t sit anywhere close to a radiator without feeling uncomfortable. Should I be worried? It cost an enormous amount of money and I don’t know what to do.