Best Viessmann System Boilers 2023 Re January 20, 2023

Best Viessmann System Boilers 2023

Viessmann boiler

Homes with more than one bathroom and more than 3 bedrooms as they are able to store hot water in a separate tank ready to use when needed. However, those that already have a system boiler installed in their home will know that this extra hot water storage tank can take up a lot of room in your home.

Both system boilers and regular boilers are not recommended for homes with limited space. If you live in a city location such as London, your home will benefit a lot more from a combi boiler, as they take up less room in your home.

If you’re unsure what central heating is currently installed inside your home, we have a separate blog that explains how the different systems work and how to identify which system is in your home.

We can help you identify this whilst getting a quote on a new boiler from the WarmZilla website.
Once you have finished this blog, of course, why not head over to our Boiler Comparison tool, which allows you to compare up to three boilers at one time.

This comparison tool also allows you to compare your current boiler against two other boiler models and brands, to help you find the most reliable and most energy-efficient system boiler for your home.

Now that you’ve figured out which system is in your home, if you would like more information about how it works we have the following blogs that may be able to help:

Throughout this blog, we will touch base on how a system boiler works. We will also be looking at Viessmann’s best system boilers, their features and their prices. We will be looking at the prices from an online supplier in comparison to the cost of a Viessmann system boiler, including the ultimate WarmZilla package.

We will also be looking into Viessmann as a brand and their customer reviews to help you decide which Viessmann boiler model is best suited for your home. In addition to this, we will also recommend some alternative brands that you may want to consider, including the best Worcester Bosch and Vaillant system boilers on the market.

How System Boilers Work

Cold water from the mains enters the boiler first. The heat exchanger will heat up the water and as it heats up, the water is then transferred into the hot water cylinder. Here is where it will stay until you need it. As a result of having a larger amount of water available, multiple taps or showers can be used at once.

A system boiler has a separate hot water storage cylinder so it can sometimes be difficult to tell the difference between this type of boiler and a regular, standard boiler. Although, it’s important to remember that a system boiler only requires a boiler and a cylinder, whereas a regular has a cylinder and an additional tank in the attic.

This is the reason why many prefer system boilers over conventional, regular boilers. On the other hand, regular boilers are ideal for those with different needs, such as homes with older radiators or those areas with low water pressure.

Best Viessmann System Boilers 2022

Viessmann currently only has two system boiler models. Nevertheless, let’s get into the details about both system boiler models on the market.

Viessmann 100-W System Gas Boiler

Viessmann Vitodens boiler

The Viessmann Vitodens 100-W system boiler is a fantastic and reliable wall mounted gas condensing boiler. This system boiler is available in a 11kW, 19kW, 25kW and a 32kW model.

This system boiler will be perfect for larger homes with more than one bathroom that demand water to multiple taps at once.

With an efficiency rating of 94% and an ErP A-rating for heat, the Vitodens 100-W system boiler is a very reliable system boiler that can also help you to reduce your carbon footprint as well as your energy bills.

Viessmann refers to their boilers as “The new generation of heating systems. Greater efficiency, lower emissions, simple operation. Future-proof, durable and digital.” Viessmann boilers are hydrogen ready, setting the standards for the future with a H2 20% blend.

The Viessmann Vitodens 100-W system boiler is fitted with an efficient and reliable Inox-Radial heat exchanger with MatriX cylinder burner. The cylinder helps to ensure that the heat is distributed cleanly and efficiently and won’t corrode or fail as with most other boilers.

With a high modulation ratio of 1:6, the boiler reduces or increases its operating power for any room environment. This reduces heating bills and wear and tear.

It also comes with an LCD touchscreen which makes this system boiler easy to use. It also comes with an optional external weather detector which allows the boiler to react to outside weather conditions and increase or decrease temperatures accordingly, keeping you nice and cozy at all times.


  • Compact design and low weight
  • Quiet operation thanks to low fan speed
  • Available in outputs from 3.2 to 32 kW
  • High-quality stainless steel Inox-Radial heat exchanger
  • Up to 94% of the fuel used is converted into heat
  • 5-year manufacturer’s guarantee with the option to extend by a further 7 years
  • Hydrogen Ready Boiler (H2 20% blend)
  • Class A-rated for energy efficiency
  • Low CO2 emissions for reduced environmental impact
  • User friendly LED Touch screen for easy operation
  • Optional ViCare Thermostat means no third-party controls are required
  • Lambda Pro Combustion Control

Viessmann Vitodens 100-W Prices

Boiler ModelPrice from an Online Supplier* (Boiler Only. Inc. VAT)WarmZilla Package
Viessmann Vitodens 100-W System 11kW£1,090.79N/A
Viessmann Vitodens 100-W System 19kW£1,126.79£2,199.00
Viessmann Vitodens 100-W System 25kW£1,174.79£2,299.00
Viessmann Vitodens 100-W System 32kW£1,235.96


This is probably a great time to mention all of the additional extras that come with your WarmZilla boiler package. We appreciate that the cost may be more expensive, however, with the extras such as a system cleanse prior to your new boiler system is installed, will help to prevent any debris build-up that may be left in the pipes from entering your new system, stopping your new boiler from working.

The chemical inhibitor is also put into your system for additional protection and a magnetic system filter for ongoing protection.

What is included in the WarmZilla boiler package?

  • Horizontal Flue kit
  • Rewiring of the existing thermostat
  • Up to 12-years warranty on all Viessmann Boilers
  • System Cleanse of your heating system
  • Magnetic system filter for ongoing protection
  • Chemical Inhibitor for extra protection
  • Removal of existing boiler and associated parts
  • Installation by a qualified Gas Safe Engineer

Viessmann Vitodens 200-W System Gas Boiler

The Viessmann Vitodens 200-W system gas boiler range is available in 11kW, 19kW, 25kW and a 32kW system boiler. This particular boiler model is also available as a combi boiler.

The Viessmann 200-W has been designed with customers in mind. This flexible and efficient wall-mountable condensing gas boiler is fitted with the same Inox-Radial heat exchanger as the Vitodens 100-W.

The Vitodens 200-W has a new 7-inch electron E3 control platform meaning that it can be controlled remotely via an app on your smart device. When controlling the Vitodens 200-W via the ViCare app, a Viessmann Trained Installer will automatically be notified in the event of a fault, so that you can ensure that your boiler is working efficiently at all times.

Although, as mentioned, you will need space in your home for an additional hot water cylinder, the boiler itself can be installed neatly inside a kitchen cupboard, out of sight, out of mind. Its modern, functional design, as well as its plain matt surface, helps this boiler to blend harmoniously into any living environment.

This system boiler model is extremely easy to maintain as all components are from the front, with no side clearance for servicing if required.

Here are the main features of the Viessmann Vitodens 200-W:

  • Up to 98% of the fuel used is converted into heat
  • Quiet operation thanks to low fan speed
  • Compact dimensions, only 450 mm wide
  • *Easy to operate Vitotronic control unit with a 7-inch colour touchscreen
  • Integrated WiFi interface for internet connection
  • Modulation range 1:17
  • Hydrogen Ready Boiler (H2 20% blend)
  • Energy efficiency class: A
  • Optionally available as combi or system boiler
  • Convenient operation at eye-level through upwards movable display
  • New environmentally responsible MatriX-Plus burner

Viessmann Vitodens 200-W Prices

Unfortunately, WarmZilla does not currently sell the Viessmann Vitodens 200-W, however, here are the prices from a reliable online boiler supplier.


Boiler Model

Price from an Online Supplier*

(Boiler Only Inc. VAT)

WarmZilla Package
Viessmann 200-W System 11kW£1,403.98N/A
Viessmann 200-W System 19kW£1,510.98N/A
Viessmann 200-W System 25kW£1,632.98N/A
Viessmann 200-W System 32kW£1,774.86N/A

Viessmann Brand Reviews

Before we get into Viessmann’s brand reviews, we think it’s important that you research the brand of the boiler that you are investing in, to ensure that you are satisfied with the brand. Here is a summary of Viessmann’s history.

The Viessmann Group is a German manufacturer of heating, industrial, and refrigeration systems headquartered in Allendorf, Germany.

Johann Viessman laid down the foundations for heating solutions in 1928, after originally specialising in being a locksmith. At that time, boilers were generally made from cast iron and only slowly reached operating temperature, however, Viessmann eventually developed and built a new generation of boilers, made with steel.

Later, in 1947, Dr Hans Viessmann, the son of Johann took over his father’s company that had 35 employees at the time and grew the company to over 100 employees. By 1957 Viessmann Group grew to 350 employees and were producing over 5000 boilers a year. You can visit the Viessmann website for more information on the history of Viessmann.

Now, let’s have a look at what Viessmann’s customers have to say about their Viessmann boiler.

With an average rating of 4.5 out of 5 on Trustpilot with over 3k reviews, you know that you are dealing with a good company that cares about its customers.

One customer said, Quick, efficient and since installation (mid last year) it has performed very well indeed.”

Another said, “Really pleased with new boiler, hot water straight away. House lovely and warm.”.

During the Which? Best Boiler Brand Survey 2021, over 8,000 customers and 150 Which? Trusted Traders were asked to score Viessmann boilers based on their reliability, how likely they are to recommend their Viessmann boilers to friends and family, the build quality of the boiler, the ease of servicing and availability of spares and parts. 

Viessmann scored an overall 81% brand score. Customers and tradesmen scored an amazing 5 out of 5 stars for reliability and customer score, and 4 out of 5 stars for their overall engineer recommendation score, which supports the fact that Viessmann are a highly reliable and efficient boiler brand.

Is It Worth Getting A New System Boiler?

With condensing technology, system boilers are extremely efficient, with both Viessmann system boiler models achieving over 90% efficiency in optimum conditions.

Another advantage of gas system boilers is their ability to supply multiple bathrooms and taps with hot water at the same time. This is great for large families and is part of the reason why system boilers are one of the most popular types around.

Pros of a system boiler

  • Constant hot water
  • Energy-efficient and environmentally friendly
  • There is no need for a cold water tank
  • Flow rates tend to be high and at mains pressure
  • Affordable running costs
  • Higher efficiency than other boilers, helping you save money on your energy bills
  • Can be used with solar thermal systems
  • No need for a cistern in the attic

Cons of a system boiler

However, there are a few disadvantages when it comes to this model type:

  • Your hot water may need to be reheated
  • If you want your hot water ready for a certain time, you will need to pre-program your boiler
  • Requires a little extra space for the hot water cylinder, normally fitted in an airing cupboard
  • You may need insulation in order to stop heat loss

Alternative Boiler Brands To Consider

At this point, you may have decided that a Viessmann boiler is definitely what you are looking for. However, we thought we would suggest some alternative system boiler brands and ranges, just in case you wanted to discuss other options before making your final decision.

Another great brand that WarmZilla highly recommend is Worcester Bosch boilers.

When it comes to system boiler recommendations, we would suggest taking a look at the Worcester Bosch Greenstar i System Boiler Range.

The Worcester-Bosch Greenstar i System boiler range is one of a range of highly energy-efficient A-rated gas boilers and are rated very highly by SEDBUK 2009. This system boiler is available in 8 kW outputs, from 9kW to 30kW.

As we know, with this being a system boiler, the Worcester-Bosch Greenstar i system boiler range will require a hot water storage cylinder; however, it doesn’t require a feed and expansion cistern as would a regular boiler. This makes the Greenstar i range a quick and easy boiler installation as well as being efficient and economical to run.

Another reason why WarmZilla vouch for Worcester Bosch boilers is because the heat from the waste gases, that would otherwise be lost through the flue, is recycled. This heat is then used as output, powering your domestic hot water and central heating with what otherwise would be wasted energy, making the Worcester Bosch Greenstar i system boiler range is up to 30% cheaper to run than some older boilers.

According to an online boiler supplier*, the Worcester Bosch Greenstar i system boiler range can cost between £948.98 (inc. VAT) and £1,114.14 (inc. VAT). This is the cost for the boiler alone.

As mentioned, you get a lot more included when you purchase a new boiler with WarmZilla. Click here to get a quote in seconds.

Main features for the Worcester Bosch Greenstar i System Boiler:

  • ERP rating: A HEAT
  • Efficiency Rating: 94%
  • Band Rating: A Rated
  • LPG Compatible: Yes
  • Standard Warranty: 5 Years
  • kW Options: 24.6 kW
  • Mounting: Wall-mounted

If you like the sound of what Worcester Bosch system boilers have to offer, then you can also check out the Worcester Bosch Greenstar 8000 Life & Style ranges, which are available in both a 30kW and 35kW output, perfect for larger homes.

Another brand that we highly recommend is Vaillant, more specifically, the Vaillant EcoTec Plus when looking at reliable system boiler ranges.

The EcoTec Plus system boiler range from Vaillant is a fantastic and low energy consumption system boiler, with an average efficiency rating of 94%. It has excellent performance for hot water and central heating – and lower fuel bills for you.

One of the best features of the Vaillant EcoTec Plus is that it is built to know when you don’t need as much heating power. When this signal is sent to the system, it can drop to using 16% of its maximum power saving on fuel and money.

The Vaillant EcoTec Plus is available in 8 different kW outputs, similar to the Worcester Bosch Greenstar i system boiler range, ranging from 12kW to 64kW, meaning that this boiler can be used in both domestic and industrial settings.

With its straightforward backlit display, similar to the Viessmann, and it’s stainless-steel heat exchanger and premium components, it’s really one of the top system boilers available on the market.

Looking at cost, the Vaillant EcoTec Plus system boiler range comes in at slightly cheaper than the Viessmann Vitodens, costing between £955.63 (inc. VAT) and £1,538.98 (inc.VAT, for the 37kW), according to an online boiler supplier*.

Main features for the Vaillant EcoTec System Boiler:

  • For use with Unvented Systems.
  • Stainless steel heat exchanger
  • Advanced modulation during low usage to ensure maximum efficiency
  • New high-efficiency pump to reduce energy consumption
  • Stylish contemporary case design to ensure a seamless fit with home decor
  • ErP Compliant
  • Lightweight and compact
  • Natural Gas fuelled
  • Includes 2 stage frost thermostat
  • Built-in pump and expansion vessel
  • Compatible with Unvented systems

Overall, the Viessmann Vitodens 100-W and 200-W system boilers, as well as the alternative boiler models discussed throughout this blog are reliable and efficient boilers, loved by their customers, and would make a great addition to your home.

*Average boiler prices were taken from an online heating supplier on the 20th of January 2022. Prices are for the boiler alone and may be subject to change.

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