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Vaillant ecoTEC Plus 835 vs Viessmann 050-W

Rob Wells
By: Rob Wells
Updated: 18th October 2023

Viessmann Vitodens 050-W vs Vaillant ecotec plus 835

Vaillant and Viessmann are boiler brands you can trust.

So if you’re looking for a new combi boiler, you won’t do much better than the ecoTEC Plus or 050-W ranges. And we’ve picked two boilers from these ranges to put head-to-head: Vaillant ecoTEC Plus 835 vs Viessmann 050-W 35.

They’re well suited to homes with around 10-15 radiators, a bathroom and an ensuite. If this sounds like your home read on, if not find a boiler better suited to your needs:

Vaillant ecoTEC vs Viessmann Vitodens

These are both wall-mounted gas-fired combi boilers. This means that your home must be connected to the gas network. Over 80% of properties in the UK are but if yours isn’t then you’ll need an alternative to gas boiler.

As combi boilers you won’t need a hot water cylinder – as you would with a system boiler. This will save you space but does limit the hot water demand a combi can meet. So if you have 2 or more full size bathrooms a combi boiler won’t be enough for your home.

Let’s take a look at these boilers in a little more detail.

Manufacturer Viessmann 050-W 35 Vaillant ecoTEC Plus 835
CH output 33 kW 32.2 kW
DHW output 35 kW 35 kW
ErP Rating 94% 94%
NOx Emissions Class 5 (best) Class 5 (best)
Max flow rate litres/min 14.1 14.3
Hot Water Temperature Controls? Yes Yes
Concealed User Controls? No Yes
LPG Yes Yes
Max warranty 7 years 10 years
Dimensions 707 x 400 x 350mm 720 x 440 x 372mm
Other Outputs 29kW 25, 32 or 38kW

The output ratings in this table are for central heating (CH) and domestic hot water (DHW).

You can also compare more Vaillant and Viessmann boilers with our Boiler Comparison Tool.

Viessmann Vitodens 050-W 35 kW

Key features

  • High efficiency A rated modulating pump with a modulation range up to 1:4
  • Inox-Radial heat exchanger and cylinder burner made from stainless steel for high efficiency and reduced corrosion
  • Ideal for installation in smaller living areas due to compact dimensions with height of just 707mm and recessed fittings not requiring pipe cover
  • Easy frontal access to serviceable parts e.g. plate heat exchanger
  • Extensive range of accessories to make boiler suitable for either new build or replacement.
  • Electronic boiler control unit for thermostatic mode and weather compensated mode is already integrated alongside a frost stat. The outside temperature sensor is available as an accessory.

Vaillant ecoTEC plus 835 35kW Combi Gas Boiler

Key features

  • User friendly backlit display with simple push button programming
  • Stainless-steel heat exchanger delivers high efficiency and reduced corrosion
  • Quiet operation with Quiet Mark accreditation which is awarded to manufacturers of the quietest products
  • Wide range of heating control options, from analogue timer to vSMART? smartphone app
  • High performance delivering hot water within 5 seconds with no need for a hot water cylinder
  • Built in frost protection to keep the boiler working through coldest months.

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How much do they cost?

Vaillant's prices tend to be slightly higher than Viessmann.

Based on our research the ecoTEC plus 35kW combi is likely to cost around £1,250-£1,350. The Viessmann Vitodens 050-W 35kW combi boiler, however, tend to come in a little cheaper at £950-£1,100. This means that in some cases choosing a Viessmann over a Vaillant boiler could save you between £300 – £400.

However, these prices don’t include the cost of installation. And this will vary depending on the installer you hire for the job.

To get the best price for a new boiler installation, we highly recommend getting at least 3 quotes from different installers. This will give you the best chance of getting the perfect deal. You can get free quotes from trusted engineers near you by using our service.

Repairs and warranties

The longest warranties available on these boilers are 7 years on this Viessmann and 10 years on the Vaillant ecoTEC Plus.

To get these extended warranties, the boiler must be fitted by an installer accredited by the manufacturer. So make sure you ask when comparing quotes.

It's also worth noting that the heat exchanger in the Viessmann is covered by a 10 year warranty. Covering corrosion damage from leaks.

Heating controls

Viessmann and Vaillant both offer a wide range of heating controls:

  • Plug-in analogue timers
  • Programmable room thermostats
  • Weather compensation
  • Smart phone app-based controls

However, in the case of these boiler models, the Viessmann 050-W isn’t smart phone compatible. But you can control the Vaillant ecoTEC plus from your phone using the vSMART? app (Android and iOS).

Which boiler comes out on top?

Turn to the Vaillant ecoTEC Plus and you’ll get

  • A higher flow rate
  • Longer warranty
  • The ability to control the heating using your smartphone

This boiler has also been Quiet Mark accredited, making it one of the quietest combi boilers around. The bad news is that these features are reflected in the higher price tag.

The Viessmann is often more affordable and is also smaller, making it a great option for homes that are tight on space. And, despite the shorter warranty, the Viessmann heat exchanger is covered for 10 years.

Whether you invest in a Vaillant or a Viessmann boiler, you're making a wise choice.

Both brands have great reputations amongst homeowners and engineers for reliability and heating performance. And in terms of efficiency, both brands deliver A-rated heating – which should keep your running costs and carbon emissions to a minimum.

Time to find an installer

Have you decided which boiler is right for your home? Then it’s time to find an installer – and even if you’re not sure which boiler to get, a trained heating engineer can offer expert advice.

To find the most competitive quote for a new boiler, we recommend comparing quotes. Agreeing to the first quote you get could see you miss out on a more competitive price.

This might sound like hassle but that’s where we can help. Tap through this simple online form and you’ll get free quotes from up to three installers in your area. Soon after you’ve finished the form, you’ll be matched with local installers. Then they’ll be in touch to arrange a quote. It’s never been easier to get the best price for a new boiler.

Rob Wells

About the author

Rob Wells

Rob is another of our resident home heating experts. He manages our external partnerships, making sure you get the most up to date information.

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