Viessmann Vitodens 100-W Review

Viessmann Vitodens 100-W Review is a top search term since it was adjudged a “UK Best Buy” by one of the most prominent independent UK Consumer Research magazines.  These condensing gas boilers are one of the highest efficiency boilers available not only in the UK, but around the world.  They also sit at an attractive price point compared to other boilers available in the UK.   That often times gives people the impression that it’s a cheap boiler.  But Viessmann Boilers are one of the most technologically advanced boilers available in the world at the moment.  How do Viessmann manage to keep the price low, and more importantly, is the Vitodens 100-W boiler any good?  Let’s find out.

About Viessmann Boilers

viessmann 100-w review

One of the biggest international manufacturers of commercial heating systems, Viessmann have rapidly become the domestic boiler of choice around the world as well.  Viessmann, founded in 1917, has over 12,000 employees across the world.  They are truly international with presence in 12 countries with 23 production divisions, subsidiaries and representations in 74 countries, and 120 sales offices around the world.  Viessmann’s commercial boilers heat some of UK’s biggest establishments, including Cardiff’s Principality Stadium.

Viessmann have also been awarded a multitude of awards over the course of their history. Recent awards include:

  • Red Dot Award: Product Design.
  • Trophée des Usines.
  • iF product design award.
  • Number 1 Trade Partner.
  • Good Practice Energy Efficiency.

Their foray into the UK market has been comparatively recent, 1989.  They are headquartered today at Telford.  And their current product range includes gas, oil, steam and biomass boilers, hot water cylinders, combined heat and power generation, photovoltaics, air and ground source heat pumps, refrigeration cabinets, coldrooms and biogas plants.

Viessmann Vitodens 100-W Review


As Viessmann Approved Installers, Boilerhut have installed thousands of Viessmann Vitodens 100-W review boilers all over the UK.  These are fantastic boilers, with ErP Heating Seasonal Efficiency of 94% on the 100-W and a whopping 98% on the Vitodens 200-W (which is a higher end model).  And because they are designed to be lightweight and compact in their dimensions, installers find them very easy to site and install.  What’s more, they are consistently regarded as one of the quietest boilers in their class, at noise emission levels of only 35dB, so you don’t hear the boiler humming when you’re trying to catch a warm, quiet night’s sleep.

Let’s delve deeper into the nitty-gritties of the Viessmann Vitodens 100-W Review.


You can get an online quote for a Viessmann Vitodens 100-W review and installation within minutes by going through our free, no obligation quoting system below.  Just enter your postcode below and hit the green button:

Features and benefits

  • Energy efficiency class: A
  • ErP Heating Seasonal Efficiency – 94%
  • Standard 5 year comprehensive warranty
  • Extended 10 years warranty if installed by Boilerhut
  • Gas-fired wall mounted unit
  • Available in outputs from 4.7 to 35 kW
  • Modulation range up to 1:6
  • Modulating cylinder burner
  • User friendly control via backlit touchscreen
  • Constant temperature control and weather compensated operation (an outside temperature sensor is available for weather compensation)
  • Designed to be used with multiple boilers on one chimney system, if required

Reliability and Durability

Viessmann Vitodens 100-W review boilers are made in Germany.  Now, before we go all patriotic and say we should only buy British boilers, there are no true “British boilers” anymore.  Worcester are owned by Bosch.  Vaillant is German.  Baxi are headquartered in The Netherlands etc. etc.  We can go on and on, but the reality is the clothes and shoes you wear are made in India, your electronics in China, and pretty much everything else is outsourced too.  Now, as far as high efficiency condensing boiler supremacy goes, Viessmann are the undisputed leaders in Germany, and in most of Europe with close to 70% market share.  Germans prefer quality and efficiency over money, whereas in the UK, price and brand reputation are the biggest motivating factors.  All that is changing however as Viessmann’s market share in the UK is increasing year-on-year.

Now, I am sure we all can agree that German engineering is all about efficiency and innovation.  Viessmann have years and years of experience in the manufacturing of gas-fired wall mounted condensing boilers, and they have refined them over all those years with innovative technology and services.  Plus, they have high standards of product quality and performance, which means even if their earlier models had reliability or parts problems, Viessmann worked hard on rectifying those and building a more robust, reliable and efficient product.

Parts Availability

One of the earlier complaints that Viessmann boilers faced was non-availability of parts.  Which is something they have also rectified by investing in a goods distribution/logistics centre in Telford, Shrophsire.  All Viessmann boilers, kits and parts are also available at all Plumbases across the UK.  So, not only are Viessmann Vitodens 100-W boilers one of the most efficient and reliable boilers you can buy in the UK in 2018, in the rare event of any problem with the boiler, a Viessmann engineer can be at your doorstep within 24-48 hours, and parts can be replaced just as quickly.

Viessmann Vitodens 100-W Review – Innovative Technology

Inox-Radial Stainless Steel Heat Exchanger

condensing boiler, stainless steel heat exchanger

Patented Inox-Radial Stainless Steel Heat Exchanger.  Phew!  That sounds like a mouthful.  But this specific internal component, described as an “impressive piece of kit” by our installers and engineers alike, is unique to Viessmann.  Unlike a lot of other boiler manufacturers in the UK, who source their aluminium heat exchangers from third parties, Viessmann have this technology patented, and they also manufacture it in-house.  This is a massive factor in Viessmann’s superiority.  In a couple of ways:

  • Stainless Steel, especially Inox, is the highest grade of stainless steel available.
  • Inox Stainless Steel is more efficient, reliable, durable and corrosion resistant compared to aluminium.
  • This helps Viessmann achieve 94% ErP efficiency on 100-W and 98% ErP efficiency on 200-W.
  • Almost all major boiler manufacturers in the UK source their aluminium heat exchangers from third parties.
  • Manufacturing it in-house gives them the freedom to sell their boilers at an attractive price point.
  • Because of the durability of stainless steel, Viessmann can offer 10 years warranty.

CFS (Combined Flue System) and Combined Condensate & PRV

Viessmann Vitodens 100-W Review

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.  Viessmann’s entire boiler range also have combined PRV and condensate connections that can also be routed in to 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.

Wireless Roomstats and Weather Compensation

Viessmann Vitodens 100-W Review - Vitotronic Controller

*Currently only compatible with the 200-W. New Viessmann controls coming soon for the 100-W.

Viessmann’s Vitotronic remote control units are ideal for use in living spaces.  Not only do they look great with a modern glosssy neat design, but with Viessmann’s standardised operating philosophy, they are fairly easy and intuitive to use helping you to manage your heating system at all times.  The control unit pictured above is only compatible with the Viessmann 200-W and above models.  But with the new building regulations coming to the UK, Viessmann are about to introduce their own range of smart controls for their entire boiler range, including the Viessmann Vitodens 100-W Review and 050-W.

Viessmann Vitodens 100-W Review – The Verdict

On top of winning “UK Best Buy” awards, or pumping out a whopping seasonal efficiency of 94% and 98% (on 200-W), or dominating the German and European markets, or having our engineers and installers singing its praises, I think our verdict is pretty straightforward.  You simply cannot go wrong with choosing a Viessmann boiler in 2018, especially the Vitodens 100-W.  What’s more, if you get the boiler installed by a Viessmann Premium Partner and Approved Installer like Boilerhut, you will have your boiler installed to the highest standards.  And because we can get you extended 10 year warranties at exclusive online prices, you can enjoy trouble free winters with your family for the next decade at the very minimum.  And because their Inox-Radial Stainless Steel Heat Exchanger is built to last, we expect these Viessmann boilers to last decades.

If you want to know which Viessmann Vitodens 100-W boiler is best for your property, you can get an online boiler quote within minutes.  Just enter your postcode below and hit the green button:

22 replies
  1. Jay Kay
    Jay Kay says:

    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?

    • Ashish Sebastian
      Ashish Sebastian says:

      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,
      Boilerhut Ltd

  2. Kim
    Kim says:

    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.

    • Ashish Sebastian
      Ashish Sebastian says:

      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,
      Boilerhut Ltd

  3. Peter
    Peter says:


    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,

    • Ashish Sebastian
      Ashish Sebastian says:

      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:

      Best regards,
      Boilerhut Ltd

  4. Debbie
    Debbie says:

    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.

    • Bryn Lloyd
      Bryn Lloyd says:

      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,

      Boilerhut Ltd

  5. Barry
    Barry says:

    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?



    • Bryn Lloyd
      Bryn Lloyd says:

      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,

      Boilerhut Ltd

  6. Elena
    Elena says:

    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.

    • Bryn Lloyd
      Bryn Lloyd says:

      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,

      Boilerhut Ltd

  7. Julliana Jambaya
    Julliana Jambaya says:

    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

    • Bryn Lloyd
      Bryn Lloyd says:

      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:

      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,

      Boilerhut Ltd


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