Vaillant atmoTEC pro vs. atmoTEC plus: what are the differences and which to choose

We are still preparing products.

But you can look at other categories.

Vaillant atmoTEC pro vs. atmoTEC plus: what's the difference and which to choose

When a customer comes with a request for a new combi boiler with instantaneous domestic hot water heating and, while browsing the catalogue, comes across two lines with similarly sounding names – atmoTEC pro and atmoTEC plus – most of them pause and ask: "What's actually the difference? Is it just marketing naming, or are these genuinely different products?" The answer is clear: these are different products, designed for partially different situations and customers. This article will help you understand where the differences really matter – and where, on the other hand, they aren't as significant as they might seem at first glance.

Both series are atmospheric boilers (without forced flue gas extraction, with natural chimney draught), belong to the low-temperature combi boiler category, and are designed for heating flats and houses combined with instantaneous DHW heating. But this is exactly where their paths start to diverge a little.

What does "atmo" in the name mean – a reminder of the basics

Before we get into the pro vs. plus comparison, it's important to clarify why the "atmo" prefix matters at all. An atmospheric boiler burns gas at atmospheric pressure – it draws combustion air directly from the room where the boiler is installed, and exhausts flue gases by natural draught into the chimney. This has specific consequences:

The boiler requires a functional, certified chimney with sufficient draught.
The installation space must have a secured air supply (min. cross-section of ventilation openings according to output).
No electrical energy is needed to run a flue gas fan (lower power consumption during operation).
Atmospheric boilers are usually quieter than turbo boilers, since they have no fan in the flue gas path.

If you're interested in how atmoTEC differs from the turboTEC variant (i.e. boilers with forced flue gas extraction via plastic concentric piping), you'll find a detailed comparison in the article Atmospheric vs. turbo boiler with DHW preparation: which type is better for you.

atmoTEC pro – basic characteristics

The atmoTEC pro series is the so-called entry line of Vaillant atmospheric combi boilers. The word "pro" here doesn't mean "professional" in the sense of extra features – quite the opposite, it's a series that focuses on reliability, simplicity and a reasonable price. In practice, this means that the boiler has everything a flat or house really needs, but without additional electronics or extended communication interfaces.

This line includes, for example, the Vaillant atmoTEC pro VUW SK 200/3-3 with a heat output of 11–20 kW and the Vaillant atmoTEC pro VUW SK 240/3-3 with an output of 11–24 kW. The number in the designation (200, 240) corresponds to the maximum heat output in kW/h, which is simplified to the output for DHW heating. The third digit "3" in the suffix denotes the product generation.

What atmoTEC pro offers

Output modulation: The boiler modulates the burner output continuously in a range of approx. 40–100% of rated output, which reduces cycling frequency and extends component lifespan.
Instantaneous DHW heating: Hot water is heated on demand – no tank, no waiting. The flow rate when heating to 35 °C (Δt compared to inlet water) is approx. 8.2 l/min for model 200 and approx. 9.8 l/min for model 240.
Electronic control: Basic digital display with heating and DHW temperature settings, fault diagnostics via error codes.
Protective functions: Frost protection, pump anti-blocking protection, safety valve, air vent.
Weather-compensated control connection: The boiler is ready for connection of an external controller (e.g. Vaillant VRT 250 or VRC 700 via eBUS interface).
Weight and dimensions: The VUW 200/3-3 model has dimensions of approx. 440 × 720 × 338 mm (w × h × d) and weighs approx. 33 kg. The 240 model has the same dimensions with a weight of approx. 34 kg.

atmoTEC plus – what it adds compared to pro

The atmoTEC plus series is one level higher. The key representative of this series that we offer is the Vaillant atmoTEC plus VUW CZ/SK 240/3-5. The "/3-5" generation compared to "/3-3" in the pro variant is not just a cosmetic change – it brings specific extensions.

Main differences between atmoTEC plus and atmoTEC pro

Based on technical documentation and installation experience, the differences can be summarised into several areas:

Extended connectivity and control: atmoTEC plus is fully compatible with Vaillant multiMATIC and the sensoNET system – meaning it allows direct remote control and monitoring via the internet without the need for an additional adapter (with the pro series, an additional communication module is sometimes required). This is appreciated by customers who want "smart home" integration.
Improved display and user interface: The plus version has a clearer, larger display with a more intuitive menu, making it easier for ordinary users without technical training to set up.
Extended DHW temperature range: The maximum settable DHW temperature is 65 °C for the plus variant (compared to 60 °C for pro), which is important for disinfection requirements – periodically raising the temperature to 65 °C to eliminate legionella bacteria in domestic piping.
Comfort DHW pre-heating function: atmoTEC plus can keep the water in the DHW heat exchanger at a higher standby temperature, which shortens the waiting time for the first litres of hot water when opening the tap. In practice, this means hot water appears faster during normal household use.
More detailed diagnostics: The service menu is extended with more parameters, making it easier for service technicians to fine-tune and troubleshoot.
Energy class: Both types achieve class A for heating, but the plus version has optimised pump control, which contributes to slightly lower electricity consumption over the season.

Where the differences are actually smaller than you might think

It's fair to also say what is the same or almost identical. In practice, we see that sellers sometimes overstate the differences between series to justify a higher price. In reality, these aspects are nearly identical for both series:

Reliability and lifespan: Both series use the same quality of components. Vaillant has a long-standing reputation for reliability, and neither pro nor plus differs significantly in this respect.
Heating output: For the same output variant (e.g. 240), the heating output is practically identical – modulation range, efficiency at rated output, maximum heating water temperature.
Warranty period: The standard manufacturer's warranty period is the same for both series (2 years with standard registration, extended when registered on the Vaillant portal).
Chimney requirements: The same chimney type (certified draught chimney for gas fuel, minimum cross-section according to output – usually 150 mm internal diameter for outputs up to 24 kW).
Installation dimensions: The external dimensions are practically the same, which matters in renovations where the boiler replaces an older model in an existing recess.

Technical parameters side by side – a clear table

Parameter	atmoTEC pro 200/3-3	atmoTEC pro 240/3-3	atmoTEC plus 240/3-5
Rated heating output (kW)	11 – 20	11 – 24	11 – 24
DHW output (kW)	20	24	24
DHW flow rate (l/min, Δt 35 K)	≈ 8.2	≈ 9.8	≈ 9.8
Max. DHW temperature (°C)	60	60	65
Max. heating water temperature (°C)	80	80	80
eBUS interface	yes	yes	yes (extended)
Native smart connectivity	with adapter	with adapter	native
DHW disinfection program	limited	limited	yes (65 °C)
Dimensions (w × h × d, mm)	440×720×338	440×720×338	440×720×338
Weight (kg)	≈ 33	≈ 34	≈ 35

Note: Values are indicative, based on Vaillant technical documentation. Always check the current exact parameters in the technical sheet of the specific product.

Hot water flow rate – a practical look at DHW output

One of the most frequently asked questions is whether the boiler is sufficient for the simultaneous use of multiple hot water outlets. Instantaneous heating has one basic characteristic: the output is not tank-based – the boiler heats water continuously, and its capacity is limited by the rated DHW output.

For a practical idea: at an output of 24 kW (model 240) and an inlet cold water temperature of 10 °C, you can heat:

to 45 °C (a typical shower): approx. 14.3 l/min – enough for one strong shower or one wash-basin outlet
to 40 °C (warm wash-basin tap): approx. 17 l/min
with simultaneous use of a shower mixer (8 l/min) + kitchen (3 l/min): still manageable

Where a problem arises: if you want a large bath (14–20 l/min) at the same time as another shower, instantaneous heating from a single 24 kW boiler is not enough. In such cases, you either need a storage system or a bigger boiler. More on this topic can be found in the article What flow rate of hot water can a boiler with instantaneous DHW heating provide.

Real-life scenarios – when to choose what

Scenario 1: 2+1 or 3+1 flat, one bathroom outlet

This is the situation we deal with most often. A four-storey apartment building, renovation, old DAKON boiler needs replacing. 70 m² flat, one bathroom outlet, one wash-basin tap in the kitchen. The heat loss of the flat at -15 °C is approx. 6–7 kW. In this case, the atmoTEC pro VUW SK 200/3-3 is exactly what's needed. An output of 20 kW for DHW covers both the shower and the kitchen, a heating output of 20 kW is more than sufficient, the boiler is affordably priced and works for years without problems. The plus version would only bring benefits here if the customer actively wanted smart control via mobile – which many older customers neither want nor need.

Scenario 2: House 120–150 m², two bathrooms

A house with two bathrooms and a kitchen – this is where the 240 model comes into play. The heat loss of the house is approx. 10–12 kW. The father goes for a shower in the morning while his wife is washing dishes at the same time – this simultaneous demand is where the 24 kW DHW output comes in useful. The pro 240 variant is a solid choice. We recommend atmoTEC plus 240 if the customer:

plans to install a smart thermostat and control the boiler remotely,
has small children or allergy sufferers in the house and wants the DHW disinfection program at 65 °C,
is more technically savvy and will actively use diagnostics and consumption monitoring.

Scenario 3: Holiday cottage, seasonal use

For a cottage with occasional occupancy (weekends, holidays), the pro variant is clearly the better choice. Smart connectivity might be tempting here (pre-heating before arrival), but with an atmospheric boiler in a cottage setting, it's rather marginal. The chimney at the cottage is usually adequate, and the pro version will reliably do the job without an unnecessary surcharge for plus.

Scenario 4: House with underfloor heating

Underfloor heating requires low heating water temperatures (30–45 °C), which both series can deliver. The key factor is weather-compensated control – and here the plus version has a slight edge thanks to better integration with advanced controllers. On the other hand, even the pro variant with an external weather compensator (e.g. VRC 700) is fully functional for underfloor systems.

The economics of the decision – how much you pay for the difference and when it pays off

On average, the atmoTEC plus price is 8–15% higher than the equivalent pro version of the same output. At indicative boiler prices in this category (depending on current market conditions), this can amount to a difference of hundreds of euros. So it's worth asking: will this money pay for itself?

From a purely energy-related point of view, no – the efficiency of both boilers is practically identical for the same output variant. The difference in annual gas consumption will be negligible. Investing in the plus version therefore only pays off if you actually use the additional features:

If you install a smart thermostat and remote control – the plus version saves you the cost of a separate communication adapter (the adapter typically costs €80–150, which reduces the real difference compared to pro).
If you have a family with small children and the DHW disinfection program is a priority for you – the plus version is the clear choice.
If you're a technician or building administrator and want detailed monitoring – the plus version offers you more data.

Conversely, if smart connectivity doesn't interest you, you live alone or as a couple, and you plan to set the boiler once and let it run – the pro variant is the more rational and economical choice without missing out on anything important.

Compatibility with controllers and smart systems

Nowadays, more and more customers require remote control of the boiler. Vaillant offers several levels of control:

VRT 250 / VRT 350: Basic digital thermostats without internet connection – fully compatible with both series.
VRC 700 / ambiSENSE: Advanced weather-compensated controllers with multiple circuits – work with both series via eBUS.
Vaillant sensoNET / multiMATIC: Internet-based system with smartphone control – here there is a difference: with the pro series, a separate VR 900 adapter may be required, while with the plus series the connection is more direct and native.
Integration with third-party systems (e.g. Home Assistant, Google Home): Technically possible via the Vaillant API, the same for both series when connected to the internet.

atmoTEC vs. turboTEC: a different but related question

Many customers are simultaneously dealing with the question: "Should I stay with atmospheric, or switch to a turbo boiler?" If you have a functional certified chimney, atmoTEC is a solid and economical choice. If a chimney isn't available (e.g. new build, apartment block without a chimney flue), turboTEC comes into play – for example the Vaillant turboTEC pro VUW SK 202/3-3 or the Vaillant turboTEC pro VUW SK 242/3-3, which discharge flue gases through plastic piping via the façade or roof. This topic is discussed in more detail in the article Atmospheric vs. turbo boiler with DHW preparation: which type is better for you.

What not to forget when purchasing and installing

Regardless of whether you choose pro or plus, the same installation requirements and practical recommendations apply:

Chimney inspection before installation: Have the chimney professionally inspected and revised – an atmospheric boiler depends on chimney draught. A neglected chimney is the most common cause of malfunctions and incorrect operation.
Air supply: The room with the boiler must have a secured supply of fresh air. According to STN EN standards, specific ventilation areas apply – for outputs up to 24 kW, usually a minimum of 150 cm² for permanent ventilation openings.
Installation by an authorised person only: Installation of a gas boiler must be carried out by an authorised technician with a valid certificate. Don't underestimate this – besides safety, it's a warranty condition.
Water filtration and treatment: If you have hard water (over 15 °dH), install a magnetic filter and consider a water softener. Limescale in DHW instantaneous heat exchangers is the second most common cause of service interventions.
Initial installation and setup: Always set up the boiler according to the current installation conditions (gas pressure, water pressure, network type). More on the installation procedure can be found in the article Installation of a low-temperature combi boiler with instantaneous DHW preparation.

Customer experience: what practice says after years of operation

Based on dozens of installations in various types of buildings, several things can be said. atmoTEC pro is a "workhorse" – robust, undemanding, easy to service. If something breaks, spare parts are readily available and service interventions are quick. Customers who have had it for years are mostly satisfied, with minimal problems.

atmoTEC plus is a boiler that customers appreciate if they actually use it to its full potential – meaning if they actively work with the app, monitor consumption, use the disinfection programs. Customers who bought it "just to have the better one" but didn't connect smart control end up using it the same way as the pro variant – and they slightly miss those extra euros spent on the upgrade.

Practical tip: If you're deciding between pro 240 and plus 240 and are hesitating, try answering one specific question: "Will I also install a smart thermostat with an internet connection alongside the boiler?" If the answer is yes, the plus variant makes sense. If not, save the money and invest it instead in a quality magnetic filter or a weather compensator.

Frequently Asked Questions (FAQ)

Is atmoTEC plus a storage system, or also instantaneous?

atmoTEC plus is also a combi boiler with instantaneous DHW heating – it is not a storage system. Water is heated on demand, without a storage tank. The comfort pre-heating function that the plus version offers keeps water in the boiler's own heat exchanger at a standby temperature, but it's not a real storage tank (the heat exchanger volume is only a few litres). The difference between the instantaneous and storage principle is explained in detail in the article Instantaneous DHW heating vs. storage tank: pros and cons in a low-temperature boiler.

Can I later add a smart module to atmoTEC pro to bring it closer to the plus version?

Yes, this is possible. atmoTEC pro supports eBUS communication and is compatible with the Vaillant VR 900 adapter, which provides internet connectivity and control via the multiMATIC app. Such a solution is functional, although the cost of the adapter needs to be factored into the overall budget. When purchasing the plus version, this connectivity is included without additional accessories.

Which model is more suitable for a flat with district heating?

In flats connected to a central heat supply, a combi gas boiler (neither pro nor plus) is not used for heating – it would only serve DHW preparation. In such a case, a classic gas instantaneous water heater is more economical than a combi boiler. A combi boiler makes sense where it provides both heating and DHW heating from a single source.

What is the difference in gas consumption between pro and plus at the same output?

In terms of combustion efficiency, both series are almost identical for the same output variant – efficiency at rated output differs by less than 1%. atmoTEC plus has slightly more optimised circulation pump control, which brings marginally lower electricity consumption (on the order of a few kWh per year), not gas. So: choosing pro vs. plus won't affect your annual gas bill in any measurable way.

Does atmoTEC plus require a special chimney compared to the pro variant?

No. Both types have the same chimney requirements – they are atmospheric boilers with natural draught. The conditions are identical: a certified chimney flue for gas fuel with a diameter corresponding to the output (for 24 kW, standard minimum internal diameter of 150 mm), functioning draught, airtightness. No special type of liner or different certification is required for the plus version.

Can I connect atmoTEC pro or plus to solar collectors?

A combi boiler with instantaneous DHW heating is not primarily designed for direct integration with a solar system – solar collectors require a storage tank to accumulate heat. Theoretically, a solution with a separate solar storage tank and the boiler as a backup heat source is possible, but the hydraulics of such a connection are more complex. For a solar installation with DHW preparation, a boiler combined with an external storage tank and a solar controller is more suitable.

Conclusion: pro or plus – a simple recommendation

If we had to give one clear recommendation without much hesitation: atmoTEC pro is a great choice for most common installations – flats, smaller houses, holiday properties – where the customer wants a reliable, quality boiler at a reasonable price without unnecessary complications. Models like the atmoTEC pro VUW SK 200/3-3 or the atmoTEC pro VUW SK 240/3-3 have years of proven operation and satisfied customers behind them.

atmoTEC plus – specifically the atmoTEC plus VUW CZ/SK 240/3-5 – is an investment that truly pays off when you plan to actively work with smart control, need the DHW disinfection program, or care about detailed consumption monitoring. In these cases, the plus version isn't just a marketing upgrade – it's a functionally different and better product for specific needs.

If you're not sure what boiler output you need in your case, we recommend reading the article What boiler output with DHW heating do I need for my house – it will help you get oriented before purchasing and avoid unnecessary oversizing or, conversely, insufficient output.

Do you have a question on this topic?

Can't decide, or dealing with a specific situation in your household? Write to us - we'll be happy to advise.