Green Central avatar

Written by

Last updated:

Viessmann Vitodens 100-W boiler review [Updated 2024]

The Viessmann Vitodens 100-W boiler review – should you buy the 100-W series?

The Viessmann Vitodens 100-W boiler has already won numerous accolades, being named a Which? Best Buy three years in a row.

Get a price on a Viessmann 100-W using this free online tool – Click here

When Viessmann announced that they would be releasing a new and improved version of the 100-W, we had no doubt that it would quickly become one of the most well-liked boilers in the UK, and we were right!

Hot Deals Icon

New look futureproof Hydrogen ready Viessmann 100 series

Viessmann 100-W review (hydrogen)

Since then, it has received a facelift and some technology that is future-proof, propelling it to the top of the list in terms of worth and durability.

This boiler is the one of the future, with WiFi built in and the ability to work with hydrogen.

Get a price on a Viessmann 100-W using this free online tool – Click here

We’ll examine every feature that contributes to the Vitodens 100 W’s popularity in this review.

Viessmann 100-W – Key facts and figures

Hydrogen ready Viessmann 100 boiler

Here’s our quick summary of the key information for the Vitodens 100-W:

  • 94% energy efficiency level.
  • ErP classification of ‘A.’
  • 33 kg in weight.
  • 700 mm in height, 400 mm in width, and 360 mm in depth.
  • Warranty of three to ten years (12-years with Boiler Central).

Viessmann 100-W boiler models available

The Viessmann Vitodens 100-W is available as both a combi and system boiler and the combi is available in three different power outputs:

  • 26kW
  • 30kW
  • 32kW

with corresponding flow rates of: 

  • 10 l/min
  • 12 l/min
  • 14.5 l/min.  

Viessmann Vitodens 100-W

Combi Boiler

Output kW


Gas Condensing


Energy Efficiency Rating


ERP Heating


ERP Water



700x400x350mm (HWD)

Stainless Steel Heat Exchanger



Wall Mounted

Flow Rate


Heat Exchanger Warranty

12 Years

Parts and Labour Warranty

12 Years

LPG Compatible


Hydrogen Ready?


Boiler Price With Installation

From £2,250

Hot Deals Icon

Is a Viessmann 100-W system boiler or combi boiler what I need?

Your needs for the hot water supply are the main deciding factor in the combi vs. system boiler debate, this is because, system boilers are probably the most suitable choice if you have two or more bathrooms and a greater demand, on the other hand, a combi will suit your needs if you only have one bathroom.

Check out this article on the best system boilers available right now.

Viessman 100 system boilers review

Everything comes down to the system boiler heating the water and storing it in a cylinder.

This then enables it to have a large amount of hot water available and to be able to supply two bathrooms at once, as needed, combi boilers heat water, as a result, the water is heated and sent directly to the outlet when you turn on the hot water tap.

Read more: Best combi boiler guide

The system boiler’s disadvantages stem primarily from the space required for the cylinder and the possibility of a long wait for hot water if the pre-heated supply has been depleted.

If you turn on the hot tap while someone is taking a shower on the combi boiler, they may be met with a gush of freezing cold water.

Hot Deals Icon

Viessman Vitodens 100-w Combi boiler review

If you want a power shower, your options with a combi boiler will be limited by your water pressure.

If that is a must, you should check the main pressure in your area before scheduling the installation.

If this isn’t the case, the Vitodens 100-w combi boiler could be ideal as it’s powerful enough to heat a large number of radiators in a large house and get your hot water steaming in seconds.

Making the right decision is critical to ensuring that you have an adequate supply of hot water.

So, before you place your order, take a moment to read through our article on boiler types.

Key features of the Viessmann Vitodens 100-W boilers

Integrated Wi-Fi

The integrated Wi-Fi is a new feature for the Vitodens 100 W model, this has a significant impact on how you monitor your boiler and manage your heating system on a daily basis.

It’s also a favourite among heating engineers because the Vitoguide software allows them to remotely monitor and adjust the boiler.

If there is a problem with the boiler, the engineer can now log into the system and instantly see the error codes, allowing him to diagnose the problem.

Viessmann 100-W boiler (review)

If it cannot be repaired remotely, the engineer can come to your home with all of the necessary spare parts, making repairs quick and easy.

In addition to resolving issues, Vitoguide expedites the installation process by providing the engineer with step-by-step guides and reporting to ensure that everything is functioning properly.

The integrated Wi-Fi means that the homeowner now has several options for controlling the Vitodens 100-W.

Hot Deals Icon


The new control panel’s seven-inch full-colour LCD display provides seven different pieces of information about how the boiler is operating.

The touch screen has a discreet black panel design and is intended to be simple to use and understand.

ViCare app

Viessmann 100-W boiler (Vicare)

The ViCare app is fully compatible with the Vitodens 100 W. You can now control and adjust your home heating system from anywhere in the world. Will you be arriving home early?

No problem, you can set the thermostat to turn on thirty minutes before you arrive home. While on vacation, do you want to double-check that everything is in working order?

You can do the same, and if there are any problems, you have a direct line to an engineer who can help.

Compatible with the Tado smart thermostat

If you want even more control over your system and the chance to save up to 31% on your energy bills, you should consider a smart thermostat.

The Vitodens 100-W is compatible with Tado, one of the most popular smart thermostats in the UK, which is controlled by an app on your phone.

viessmann and tado smart thermostat
Hot Deals Icon

Tado takes heating control to the next level. It can still do all of the scheduling and reporting, but it also alerts you when it detects that no one is at home and the heating is still on.

It’ll even notify you if you leave a window open while the heating is still on. If the humidity is too high and there is a risk of mould, it will recommend that you open a window to let some fresh air in.

Designed for reliability and efficiency

Viessmann 100-W boiler (kitchen)

Viessmann’s product line already has a solid reputation for dependability, and the Vitodens 100-W is no exception.

This is a manufacturer that takes an ‘all-in’ approach to their boilers; all of the parts are manufactured by Viessmann, and they’ve all been designed to work together.

A new boiler cost starts at £2,250 fully installed from the Viessmann 100-W range.

Among the key Viessmann technologies found in the Vitodens 100-W are:

MatriX-Plus burner

This new burner reduces fuel consumption by carefully regulating heat production based on your current needs. It also has automatic combustion control and emits 40% fewer emissions.

Viessmann 100-W boiler (matrix burner)

The MatriX, which is made of special stainless steel, is not sensitive to high temperatures and thus provides dependable performance as well as a long working life.

Lambda Pro Plus combustion control

The Lambda Pro Plus ensures that the Vitodens 100 W will continue to provide a reliable source of hot water even if the gas type changes, the gas quality fluctuates, or the operating conditions change. The Lambda Pro Plus also reduces emissions, which means that system cleaning is required less frequently.

The Lambda Pro Plus accelerates the installation process by performing the necessary adjustments automatically.

This combustion control system detects the type of gas and automatically adjusts the Vitodens 100-W to work as efficiently as possible.

Hot Deals Icon

Stainless steel Inox-Radial heat exchanger

The material used for the heat exchanger makes a significant difference in both its longevity and efficiency levels.

Viessmann 100-W heat exchanger

Review of the Viessmann Vitodens 100-W boiler Compare Boiler Quotes
The Inox-Radial heat exchanger is made of stainless steel, which provides corrosion resistance that other metals cannot match.

It also means that there is virtually no heat loss, resulting in efficiency levels previously unthinkable.

Hydrogen ready (H2) Viessmann 100

Viessmann 100-W hydrogen ready

The EU has pledged to cut CO2 emissions to zero by 2050. However, this can only be accomplished without the use of fossil fuels.

Hydrogen is one of the energy sources that could provide an alternative to our current use of natural gas.

While some logistical issues remain, it is expected that this greenhouse gas-neutral energy source will be a major source of fuel for our homes.

To see how hydrogen will be used in the coming decades, read our popular article on hydrogen boilers.

The first step is to introduce an 80% natural gas and 20% hydrogen mix into the gas grid. It is hoped that by the mid-2030s, 100% hydrogen will be a reality.

All of this means that it’s critical that any boiler replacement quote you get is for a hydrogen ready boiler.

Then you’ll know that when the 20% mix is introduced, your boiler will require no technical adjustments or new parts to continue operating normally.

The Viessmann 100-W is certainly future-proof, as it can already accept a 20% hydrogen mix.

Hot Deals Icon

Modulation of up to 1:10

When a boiler modulates, it means it can reduce its power output. So, if you have a 20kW boiler but only require 10kW for heating, the boiler can reduce its flame by 50%.

Without modulation, the boiler would produce 20kW for five minutes before shutting down for five minutes.

The modulation ratio of the Vitodens 100 W is 1:10. That means it can operate at only 10% of its maximum power output.

So, if you choose the 30kW model, modulation could allow it to operate at only 3kW.

The larger the ratio, the better, and with many manufacturers only achieving modulation of 1:6, Viessmann’s 1:10 is an impressive market leader.

What are the benefits of boiler modulation?

The main advantages of boiler modulation are reduced wear and tear and increased efficiency.

Reduce wear and tear

When your boiler shuts down, several mechanical processes occur.

The fan may stop, the gas valve may close, and the pump may also stop.

Because each component has a lifespan based on the number of times it is expected to turn on and off, you’ll want to avoid unnecessary stoppages to extend the life of your boiler.

Then, in addition to the stopping and starting, the boiler will be running hotter and then cooler.

As a result, all of the components will expand and contract. Every time this happens, it puts more strain on the boiler and increases the likelihood of a breakdown.

Hot Deals Icon


Viessmann 100-W boiler (efficiency review)

Traditional boilers lacked modulation capabilities. That meant they were either fully operational or turned off.

When you consider how long it takes a boiler to warm up and then turn off when it is at its warmest, it is clear that this isn’t the most efficient way for a boiler to operate.

When a boiler has full modulation capability, it can run for longer periods of time but with fewer on/off cycles and at lower fire rates. As a result, efficiency levels have significantly increased.

Viessmann Vitodens 100-W Warranty

The warranty levels for the Vitodens 100-W vary depending on whether you choose to purchase extended coverage for an additional fee.

The 100-W comes with a five-year warranty as a basic level of protection.

Interestingly, Viessmann has decided to provide the full five-year warranty even if the installation is not performed by a Viessmann-trained engineer.

In that case, the Viessmann 050-W, for example, comes with only a three-year warranty. However, make sure the engineer is gas-safe registered so you know they have the skills and qualifications to complete the installation safely.

If you purchase your Vitodens 100-W from Boiler Central, you will receive a massive 12-year warranty.

That gives you a lot of peace of mind, knowing that you don’t have to worry about finding an engineer to do repairs or dealing with unexpected repair bills.

Make sure, however, that you keep up with your boiler’s annual servicing; all warranties require this in order for your coverage to be valid.

Viessmann 100-W review – Final verdict

Even before it was relaunched, we adored the Vitodens 100-W. So, what’s not to love about having even more functionality combined with improved systems?

It can be difficult to select the best heating system for you and your home. There are numerous manufacturers to choose from, not to mention the various models and boiler types.

Viessmann 100-W boiler (range)

Getting professional and personalised advice at this point is critical to making the right decision.

Getting a new boiler quote is the first step to having all your heating and hot water problems solved!

Hot Deals Icon
Green Central avatar

Written by

Read some of our superb solar panel installation reviews from Trustpilot

Recently had solar panels fitted by Green Central and I can’t speak highly enough of the team. The whole experience has been trouble free and I would recommend them to anyone thinking about having solar panels installed – 10/10!

Rob Schofield


Our installation is now complete! 8 solar panels fitted and the journey from initial consultation through to the end product has been seamless.
Hats off Green central, Credit where it’s due.
Will definitely spread the word!



Recently had six solar panels fitted on my house by Green Central and I couldn’t have asked for a better service. In particular, I have to highlight the exceptional communications through out, the over all smooth running process and completely stress free experience, all down to Green Central. I now have grid independence which is valuable beyond estimation.


Name *
Email *
Phone No. *
Post Code *
Name *
Email *
Phone No. *
Post Code *