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Vaillant ecoTEC 46kW & 65kW System

The Vaillant ecoTEC 46kW and 65kW System boilers are high output options that are designed for large homes and commercial buildings.

Vaillant has always been dedicated to manufacturing boilers to suit every need, which is why the brand has created the ecoTEC 46kW and 65kW Systems. Designed specifically for larger homes and most commercial sites, these natural gas boilers are extremely powerful and can be fitted in cascade to provide even higher heat outputs. Not connected to the mains gas network and like the sound of these boilers? Don’t worry. Vaillant offers an LPG conversion kit with the 46kW unit.

How Much Does this Boiler Cost?

The 46kW boiler has a price tag of around £2,200 and the larger 65kW system typically costs £2,800. This may seem quite expensive, but you need to remember that these boilers are incredibly sturdy and powerful. You also need to find out how much the installation is going to cost when shopping around. We suggest you compare quotes from different suppliers and installers to see if you can bag a great deal. Obviously, if you want to combine two or more units to achieve a higher overall output, you’ll need to spend a fair bit of money.

How will I know if this Boiler is Suitable for My Home?

Both of these boilers are system type boilers and require a separate hot water storage cylinder. Most system boilers are ideal for properties with more than one bathroom and where a lot of taps are used simultaneously, but the 45kW and 65kW ecoTEC Systems can meet higher than average heating and hot water demands. The greater your hot water requirements, the larger the hot water cylinder will need to be.

Because the outputs are so high, it’s important that you check which boiler output is ideal for your home or commercial building. If you select a boiler that is too big for your needs, it will use more fuel than necessary and make your energy bills more expensive. Before buying a new boiler, we recommend you always consult a Gas Safe registered engineer who can help you work out the correct boiler type and output for your home.

Is it a High Efficiency Boiler?

These boilers are among the most efficient options available from Vaillant. As both models have an A rating, they enable lower running costs and can help to save you some serious money on your fuel bills. The ecoTEC 46kW and 65kW System boilers feature a high efficiency stainless steel heat exchanger that minimises energy waste. When these boilers are used with Vaillant’s range of optional heating control, greater comfort and efficiency levels can be achieved.

Does this Boiler have a Good Range of Controls and Features?

Yes, both models have the same controls including a switch that lets you adjust the heating temperature and a clear display that provides feedback on fault codes. These boilers are designed to work with the uniSTOR range of hot water cylinders, which are available in different sizes and help to maximise energy savings. Key features include the stainless steel heat exchanger, a range of flues for flexible siting possibilities, an air separator that ensures the boilers remain quiet and enjoys a longer life and front access to all components for hassle-free repairs and servicing.

How long is the Warranty on this Boiler?

No matter which output you choose, you’ll receive a 5-year parts and labour warranty as standard. It’s worth checking if you can upgrade to a 7 or 10-year guarantee at the time of purchase.

ecoTEC 46kW & 65kW System Boiler Sizes and Prices

ModelTypeDimensionsMaximum Flow RateOutputEfficiency RatingTypical Price
ecoTEC 46kW SystemSystemH – 800 mm
W – 480 mm
D – 450 mm
N/A46 kWA 90% and above£2200
ecoTEC 65kW SystemSystemH – 800 mm
W – 480 mm
D – 472 mm
N/A65 kWA 90% and above£2800

Summary of Important Information

  • Priced between £2,200 and £2,800
  • Heating output of 46kW or 65kW
  • 46kW unit dimensions: 800mm (H) x 480mm (W) x 450mm (D)
  • 65kW unit dimensions: 800mm (H) x 480mm (W) x 472mm (D)
  • Both use gas as their fuel source
  • A-rated for efficiency
  • Solar compatible
  • 5-year warranty as standard

Pros and Cons

It’s hard to find fault with these well-developed and highly efficient system boilers. For a full list of pro and cons, just look below.


  • Vaillant boilers have an overall Which? score of 80%
  • Suited to large homes and commercial buildings
  • LPG compatible (46kW model only)
  • High-quality components
  • Easy to install and maintain
  • Modulating lox NOx burner – lower NOx emissions
  • Stainless steel heat exchanger – more resistance to corrosion and oxidation
  • Air separator with auto air vent and filter – removes fine particles
  • Can be installed in a cascade – combine two or more units for a higher output
  • Provides maximum energy efficiency – reduce fuel bills and carbon emissions
  • Compatible with solar thermal – additional savings
  • Compatible with wired or wireless weather compensating programmable room thermostats
  • 46kW works with LPG if required – perfect for properties off the gas grid
  • 5-year warranty


  • Requires separate cylinder
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