Is it possible to get interface or API to my Vaillant ECO-tec condensing boiler ?

February 14, 2020 1 By Smarthomes

Thanks to our knowledge at this particular lines of boilers we are able to communicate through  Programmable Room Thermostat with Weather Compensation.

The main principle of the integration mechanism between the Vaillant condensing boiler and our solution is to create an intermediary mechanism directly connected to the communication bus between the Vaillant calormatic weather controller and the Raspberry Pi device.
In order to compensate for the voltage levels that exist on the communication bus and GPIO pins, voltage converters in the form of an integrated circuit are needed.

The calormatic weather controller remains in place, but it is also connected to the Raspberry Pi point instead of being connected to the main communication bus of the boiler.

Thanks to this it is possible to control both manual calormatic and remote control using our application.

The Raspberry Pi application is able to issue an API based on the ht t p protocol which can be used to change boiler operation parameters such as:

  • Selection of the set temperature of Vaillant boiler via API
  • Selection of the heating curve level of Vaillant boiler via API (find out more about heating curve)
  • Time schedule of the boiler operation, including: Heating of domestic hot water, and premises using API and remote App
  • Advanced parameters such as pump run-on time or burner lock time – controled by API
  • and other


The complate set of available Vaillant API commands is constantly developed by our programmers.

The full specification of the API for Vaillant boilers for their Home smartphone can be found where but documentation.

We have successfully tested on:

  • Vaillant VRC calorMATIC  470
  • Vaillant VRC calorMATIC 430
  • Vaillant calorMATIC 230

We need 2-wire connection from raspberry to your calorMATIC

Vaillant calormatic API Integration

We have used API connection to the boiler as a baypassing proxy between Calormatic and eco-tec boiler.

The pin connector has been presented on the photo below.

If you need a brand new Vaillant Ecotec Gas Boiler you can check offers from our shop