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Vaillant ecoTec Pro 28 Combi Boiler – Review

German boiler manufacturer Vaillant have delivered high-quality and reliable boilers for over a century. From Johann Vaillant’s “closed-system” bathroom boiler in 1894 to the recent ecoTec Pro range, it’s no wonder that they’re now the second largest boiler manufacturer in Europe. The ecoTec Pro boiler range, which was launched in 2015, offers a series of reliable, A-rated combi boilers to suit all small to medium-sized homes and flats. Today we will be taking a closer look at the Vaillant ecoTec Pro 28.

Will the ecoTec Pro 28 be suitable for my home?

The Vaillant ecoTec Pro 28 is ideal for smaller flats or houses with up to 3 bedrooms and one bathroom. You may be better off with another type of boiler if your home has more than one bathroom and high demand for hot water. This boiler, in particular, has a central heating output of 18.9kW and a hot water output of 27.2kW, which is more than enough for smaller properties. You may be asking, why is a combi boiler only suited to smaller homes? Well, to answer that, combi boilers work off of the mains water pressure, so if you have more than one bathroom, the split in hot water flow between bathrooms will reduce the overall effectiveness of the water supply. The number of radiators installed in your home also plays a vital role in which boiler is suitable. The ecoTec Pro 28’s flow rate is at 11.1l/m, which will be suitable for up to 12 radiators.

If you’re looking for an alternative to the ecoTec Pro 28 combi boiler that can supply the same amount of hot water, we recommend the Worcester Bosch Greenstar 28CDi Compact. The 28CDi compact is also a great fit for standard-size kitchen cupboards.

For smaller homes with up to 10 radiators installed, we recommend the Vaillant ecoTec Pro 24. For up to 15 radiators, the Vaillant ecoTec Pro 30 will be the best choice.


The ecoTec Pro 28 combi boiler offers an on-board digital display, which gives accurate temperature readings for the temperature of water in the flow pipes, pressure levels, and fault codes should the boiler need servicing or if a component needs a replacement. The controls on the boiler itself are pretty standard but they do allow you to navigate through the menus on the display and switch off your boiler if you need to.

In April 2018, Boiler Plus was introduced for all combi, system and conventional gas boilers to ensure that the energy efficiency of homes nationwide is improved. Due to this new regulation, your old mechanical thermostat may no longer be compliant and will need to be replaced with time and temperature controls.

For combination boilers, there are some additional requirements in place to be compliant with Boiler Plus. Specifically, one out of four additional requirements will need to be met. These are as follows:

  1. Weather compensation – The ability to alter the water temperature from the boiler based on outdoor temperatures.
  2. Load compensation – The ability to alter the water temperature from the boiler based on the current room temperature.
  3. Smart control – A type of control that provides automation and optimisation for your boiler.
  4. PFGHRD (Passive Flue Gas Heat Recovery Device)

In addition to the on-board controls, Vaillant offer a range of digital and smart controls to give you control of both your home temperature, as well as up to 7 days of programming. If you’d prefer to dive into the world of smart thermostats, Vaillant’s vSMART offers modern and intelligent way of controlling your boiler. Despite the basic display and design, the vSMART learns from your heating habits to alter your settings on a daily basis. You will also be able to set temperatures and schedules from the smartphone app, as well as to see a breakdown of your energy use. You can check out our review of the Vaillant vSMART here. However, note that smart controls from other manufacturers such as Nest or Hive are compatible as well.


At only 720mmx440mmx340mm, the size of the Vaillant ecoTec Pro 28 is quite compact. However, there are more compact boiler options from Vaillant if you’re tight for space. Take a look at the Vaillant ecoFit Pure 825 or Worcester Bosch’s Greenstar 25Si Compact instead if you need a more space-saving boiler.


Vaillant currently offer a standard 5-year warranty with this boiler. If you do decide to have it installed by a Vaillant Advanced Installer, you can extend your warranty by a further five years and look forward to 10 years of complete peace of mind. At Hometree we’re proud to be a Vaillant Advanced Installer and can offer you extended warranties for an extra charge. All of our Vaillant boilers come with a 5-year standard warranty.

Energy Efficiency

Vaillant’s ecoTec range is highly sought after due to their high efficiency rating under the ErP (Energy related Products) directive. The ecoTec Pro has achieve a rating of 89.3%, which is an A grade for efficiency.

The ErP Directive tests all energy products (which includes boilers) to ensure that they pass certain criteria. These criteria include anything from performance, carbon footprint, and their overall energy efficiency. The ErP will step into the manufacturing process of a boiler to help improve its design to lower emissions and decrease wasted energy. If you’d like to read more about the ErP Directive, you can check out our article here.


If you’re looking for a highly efficient combi boiler for your home, the Vaillant ecoTec Pro 28 is the perfect choice. The ecoTec range was awarded the Which? Best Buy award in 2016, as well as Quiet Mark status due to its low noise output. The boiler packs a punch with its strong central heating output and hot water flow rate, which is ideal if you’re looking for a future-proof combi boiler for your small home or flat.

 Vaillant ecoTEC Pro 28
ErP rating (energy efficiency)A (89.3%)
Size (HxWxD in mm)720x440x330
Heating output (kW)18.9
How water output (kW)27.2
Flow rate (litres/min)11.1
Standard warranty (years)5 (extended warranties available)
Other available sizes (kW)24, 30

Which? boiler review

The consumer group Which? review each boiler on the market to find the most (and least) reliable boilers according to a survey completed by thousands of boiler owners. In each review, Which? supply a brand score percentage and star ratings for each category. Take a look at the Vaillant ecoTec Pro 28 ratings below:

Which? Score 
Efficiency rating★★★★★
Brand reliability★★★★☆
Brand customer score★★★★★
Ease of repair★★★★★
Ease of service★★★★★
Availability of parts and spares★★★★★
Build quality★★★★★
Engineer recommendation★★★★★
Brand score80%

Boiler manual

Vaillant ecoTec Pro 28 Combi boiler manual

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