Budget Boilers: Ariston vs Viessmann

It’s Ariston vs Viessmann…let’s get ready to rumble!!

In this 12 round bout, we’ll be breaking down the best things about Ariston and Viessmann – two of the greatest boiler manufacturers around. This battle of rivals will be judged based on the results of this middleweight 30KW budget combi boiler contest!

Are you looking for a new boiler, but not sure which one is best? That’s where we come in. We’ll compare each manufacturer’s best against each other to give you the information you need!

Before we start this colossal match, you may also find some of the following related articles useful:

In the red corner representing the German giant Viessmann, and weighing in at 37 kilos, it’s the Vitodens 050 29KW boiler!

…and in the blue corner representing the fearless rival Ariston and weighing in at 32.3 Kilos, it’s the Clas One 30KW boiler!

For a quick overview of each round in this Ariston vs Viessmann fight, see below:

1: Price Comparison

2: Brand history and background

3: Overall performance statistics

4: Physical boiler size

5: Internal components comparison

6: Overall efficiency

7: Boiler Flue Options

8: Aftercare and customer service

9: Spare parts accessibility

10: Modulation

11: User controls

12: Warranty

To oversee the match we have the referee and judge Bernard Morgan. With over 35 years of experience in the domestic boiler industry, he has all the knowledge and insight to know exactly what you, the customer, requires from a reliable, high-performance boiler. He’ll be deciding who wins each round, and ultimately, the overall victor between Ariston vs Viessmann!

Round 1: Price Comparison

So how do our two competitors compare in this fight? 

Viessmann steps up and shows its pounds, the cost for a Viessmann Vitodens 050-W combi boiler, standard flue, magnetic filter, new programmable room thermostat, chemical flush, and a powerful punch with a 10 year warranty, will be between £1,990 – £2,290.

Now it’s Ariston’s turn. With a right hook the highly-regarded Clas One 30KW boiler has become a prime example of excellent design along with improved performance. This has allowed them to rise above many other competitors. This boiler not only comes with a standard flue, magnetic filter, chemical flush, but their secret punch is the Cube S Net Wi-fi thermostat. Having one of these boilers installed will cost you between £1,790 – £2,090. 

The Ariston boiler is included with LPG compatibility – a feature that comes free of charge. However, in the case of Viessmann’s product, there is a difference of £140 needed in order to include this feature.

If we compare the two price points and what’s on offer, it’s easy to see our victor:

Round 2: Brand history and background

Let’s get ready ……..

The German manufacturer Viessmann has tricks up their sleeve and decades of experience under their belt. With 23 production companies in 12 different countries, they’ve become a worldwide company that’s made a massive impact in the heating industry. They’ve been operating since 1917, and remained ever present in the UK, with a long list of boilers under their belt including their star of the ring, the Vitodens 050-W.

In the middle of the ring is Ariston, through their half-century lifespan they’ve become known as a global expert in water heating and other heating products. With this reputation, they’ve been able to deliver excellent boilers that have provided comfortable solutions, through innovative Italian design. They’ve also become a trusted manufacturer by families all around the globe.

Round 3: Central heating, hot water and other performance statistics

A straight up comparison of how each boiler performs in their primary functions (central heating and hot water) has got to be the best way to compare, right?

Both the Viessmann Vitodens 050 and the Ariston Clas One are ideal boiler options for many different living areas, with quiet operation and small size for better installation options.

Several additional features increase the overall performance such as Weather Compensation, but sometimes a straight up comparison is what’s needed. Therefore, we’ve included some basic information of both boilers in the table below:

Ariston Clas One 30kwViessmann Vitodens 050-W 29kw
Flow Rate12.5 l/min12 l/min
Heating Rating (ErP)AA
DHW (Domestic Hot Water Rating) (ErP)AA
LPG Compatible?YesYes

As you can see from the above information, most of the statistics are the same between Ariston vs Viessmann. However, the Ariston Clas One offers a slightly improved flow rate, which means we have to crown the victor of this round to…

Round 4: Physical boiler size

The reason this is so important to homeowners is to do with the flexibility, for where you can have your boiler installed. Let’s check the weight of these bad boys! 

For Viessmann, their Vitodens 050 comes in with dimensions of 400mm x 707mm x 350mm. That means it can fit snugly into most kitchen cupboards, as well as your airing cupboard.

For Ariston, the Clas One boiler comes in at 400mm x 747mm x 385mm, making it the slightly larger option.

It’s clear here that Viessmann has the upper hand. The Vitodens 050 is the smaller of the two, so you have more options for installation!

Round 5: Internal components comparison

Here we go, let’s see how Ariston and Viessmann really get going……. 

Performance means nothing without the internal design and components to back it up. If you’ve done any research on how boilers work, you may have picked up on the importance of high efficiency – something only the highest quality components can help achieve.

Ariston steps up to boast at Viessmann with a new stainless steel ‘XtraTech’ heat exchanger inside their Clas One, and all its range. Its single coil design helps achieve high efficiency, and allows the waterways to be 142% wider. The result? A much greater chance of avoiding any blockages or obstructions. Your boiler also has a much easier job of working against any pressure drops. In short, you can rely on Ariston for peace of mind, and top-of-the-range quality design.

Now Viessmann steps forward to gloat, they’ve become well known as a German manufacturer to lead the fight in design and functionality excellence. They’ve been able to achieve this thanks to their Inox-radial stainless steel heat exchanger. Because of how heat transference occurs using this vital component, it’s able to efficiently convert the energy your Viessmann boiler is supplied into heat. On top of this, the cylinder burner (which is also made out of stainless steel) consumes very little gas, so your carbon emissions are greatly reduced – a win-win situation for you and the environment!

While we won’t want to put down Ariston too much in this respect, it’s simply Viessmann who wins. They’ve pushed the boundaries of internal component design for an ‘A-rated’ efficiency, with the proof to back it up.

Round 6: Overall efficiency

Ariston vs Viessmann: What is efficiency? 

It’s how much fuel your boiler uses to convert to energy for heating compared to how much is wasted. So the lower the efficiency score, the more energy wastage there is – a bit of a negative. It’s classed as a percentage score, which when referred to as an ErP rating, means anything from ‘G’ all the way up to ‘A+++’. 

The push-punching Viessmann Vitodens 050-W has a high efficiency rating or around 90%. However, when combined with Viessmann weather compensation, greater efficiency can be achieved.

…in comparison, the Ariston Clas One also reaches 90%. However, when fitted with the Cube S Net Wi-fi thermostat or a smart control (such as a Nest) 92-94% is achievable.

Although there’s a clear difference between the two, our judge has decided to go for a draw for this round! This is due to Ariston’s better modulation range – something we explore further down in this article!

Round 7: Boiler Flue Options

Last round before a breather in this Ariston vs Viessmann fight…

It’s important to have decent options for how you can have your boiler installed, and the same goes for your flue installation as well. Whatever you get done, it must stay within current regulations, but it’s still good to go with a manufacturer who has good flue options available to you whether this is vertical flues, external flues, or flue lengths.

With a knock out punch this one goes to Viessmann,! This is due to more options available in terms of how you can have your flue installed, as well as more options for available lengths. Viessmann 050 allow up to 15 meters horizontal and vertical. Ariston clas one max out at 7 meters. You only need to do a quick Google search to discover the options available to you. For instance, if you’re a landlord you have the option of including up to five different boilers on different floors – all of which can be connected to one single vertical flue system. 

Time for a short break to gather the senses, recharge, and top up the pressure for Ariston vs Viessmann…

During the break, if you feel like you’ve already made a decision on your preferred boiler or would like more advice, call us on 02920 650 025. Where we will be happy to answer any of your questions. You can also get yourself a free, no-obligation quote for your brand new boiler!

After a short break ……with both boilers poised in each corner…….we’re ready to start another round!  

Round 8: Aftercare and customer service

Every manufacturer will do whatever they can to deliver a boiler that can heat your home as comfortable as possible, whilst helping you save money with high efficiency. However, there’s always the possibility that you need support or advice of some kind afterward. Whether this is to answer any questions you may have, or help with making more decisions using their products, a manufacturer should always be there to help.

Every installation will include the necessary safety checks to ensure your boiler functions normally. Customer service departments are all about great communication, and it’s important that things can be explained in ways you can understand. To allow this, multiple channels of communication are provided for all your answered questions.

So with this in mind, both boilers go head to head, dodging and weaving but who gets the win between Ariston vs Viessmann…

In order to retain your boiler’s warranty, you’ll need to have it serviced once a year. 

For Ariston, they charge £80 for an annual service (excluding VAT). They have a customer service department that is open 24/7 for any questions or queries. 

Viessmann, however, does it slightly differently. To make sure your boiler is working in the best possible condition, you can expect to pay a typical price of anywhere between £65 and £80, including vat, for a service. Viessmann has excellent customer service, call out engineers are guaranteed to arrive between 24-48 hours and a first fix rate of 95%.  

A bit more understanding of each individual case is what swings the victory over to Viessmann for this round!

Round 9: Spare parts accessibility

So we are 8 rounds in and Ariston vs Viessmann are still going, showing their strengths and weaknesses.  Let’s see how they do in this round! 

A reliable manufacturer knows how important it is you get the support needed, even after you’ve had the actual boiler installed. 

Viessmann have gone to great lengths to ensure this happens with any boiler in their impressive range. They’ve even included details on their website related to the current COVID-19 situation which you can read by clicking here. The fact that this has been addressed paints a good picture of how dedicated they are to making sure their customers get the help they require. 

Viessmann engineers always carry a range of spare parts on their vehicles, for any boiler in the Viessmann range. They know from the registration detail what boiler the customer has and the location of the boiler. Along with the information they have gathered directly from the installer or customer, to assess any problems they are encountering or an error code displayed. They have a 95% first fix rate and on the rare occurrence that they do not have the part required, there are merchants all over the UK that have stock. 

Ariston has done something similar, offering details on everything available when it comes to spare parts. They also have details on their website covering this topic where you can find a national network of stockists who can provide spare parts. 

Ariston has an app called Ariston Thermo Quick Fix, it is an interactive tool for technicians that solves issues on the job about Ariston products. It allows online access to product documentation (manuals), spare parts lists, technical notes, etc. The app can be used in places where an internet connection is not available. 

Very impressive… but who is the winner?

Although this is a close round, we’d have to go with Viessmann. This is because they’ve been operating in the UK for longer, and have more availability for spare parts to be delivered and installed for you with minimal fuss!

Round 10: Modulation

Ariston vs Viessmann: What is modulation?

This is going to be a good round, both boilers are poised ready to battle it out!

This refers to how your boiler needs to match the power output (KW) to the thermal load of your central heating system. In doing so, it also improves fuel efficiency, because adapting to the current power demand helps to minimise waste. This figure is stated in ratios, so for example, a range of 1:6 would be an ideal achievement for most manufacturers and it shows better adaptability for matching the user’s output demand.

In recent years, boiler manufacturers Ariston vs Viessmann have been striving to produce ever wider modulation ratios, and 1:10 has been the ambition of many.

This is even more applicable for combi boilers such as the Viessmann’s Vitodens 050 or Ariston’s Clas One series. Most homeowners want consistency when it comes to the temperature of hot water they want, regardless of the amount of hot water that’s actually required.

Much like in our ‘Efficiency’ round, this is simply a case of better statistics. The Viessmann Vitodens 050 modulates between 1 to 4 whereas the Ariston Clas One has a modulation range between 1 and 7!

Round 11: User controls

The bruises are starting to show on either side and without good control you will lose!

Every boiler needs to be accessible for all potential users. By having easy controls, it means customers can get more out of their new boiler, and ideally save money as a result of good understanding.

Ariston has been able to develop ‘Ariston Net’ – a service they’ve specifically manufactured and developed to give the user full control of their heating. Through connections with their smartphone, PC, or other devices, users can start, stop, and change the temperature at any time for their central heating and domestic hot water. As well as this, remote diagnostics can be activated if there is ever an issue with your boiler, and can even arrange appointments at your convenience via the company’s service center!

Viessmann offer something similar in the form of several thermostat options including Tado, or Nest. But how does this affect costs? In the long run, if you monitor your energy consumption closely using these controls, you’re much more aware of what you spend on heating, meaning with a little surveillance, you can save a lot more money!

While both manufacturers certainly have strong fights in this round, Ariston have perfected the level of access required for this sort of control, making it easier for anybody to save money through their heating. The Cube S Net Wi-fi Thermostat by Ariston is ‘Ariston Net’, and is compatible with the Clas One.  

Round 12: Warranty

Wow ….. so in this Ariston vs Viessmann fight these boilers are still throwing big punches back and forth, battling it out, the finish line is near…… 

So we are here at last …..Its the final countdown! Both boilers are ready with their final pressure-punch and hoping to get a knockout!

This is another big one in terms of aftercare service for you and your boiler. A new boiler is a big investment, so a decent warranty is a must if you want to be taken care of for the next few years. By comparing warranty length, you get a simple breakdown of what’s available to you for support.

So as standard the warranties available are:-

  • Viessmann Standard warranty: 7 years
  • Ariston standard warranty: 8 years

So it’s a clear winner round? 

Winner: Ariston

BUT WAIT! Referee and Judge Bernard Morgan intervenes!

The longer your warranty, the more support you have as a customer. This can be increased even more if you’re working with a premium installer with a strong working relationship with the manufacturer. This is the case with B T Morgan, who is able to offer an extended warranty of 10 years if you have your Viessmann boiler installed through us!

Therefore the victor of this round must be changed to…

The Final Decision!

And the winner between Ariston vs Viessmann is….Viessmann!

It’s been a close call this match, as both the Viessmann Vitodens 050-w 29kw and the Ariston Clas One 30kw are fantastic boilers, and both very clearly punch above their weight.

In conclusion, we can sum up that while Viessmann may have the better boiler, the true reflection and takeaway is that there’s a clear market for both products. As an example, the price point is something that could influence your choice depending on your budget.

Ten years ago, these boilers would never have been in the same ring. This is a testament to both manufacturers as Viessmann led the way. Quality and high-spec technology, Ariston has made some serious gain with their products. We are judging budget boilers, so price points can be a major factor. The simple truth, is when Ariston boilers are combined with the Cube S Net Control, you can save up to £300 compared to the full price of a Viessmann boiler.

To make things even easier for you, we’ve got a summary of all the key points for boiler included below:

Ariston Clas One 30kwViessmann Vitodens 050 29kw
Physical Dimensions (mm)400 x 745 x 385400 x 700 x 350
Overall Efficiency90%Up to 97% {Hs}
Warranty Length8 years7 years (10 years if installed through B T Morgan)
Output Modulation1:7Up to 1:4

Want more information? Take a look at some of our articles for all the insight and support you need:

If you’ve made a final decision, get yourself a free, no-obligation quote!