This board is a modified version of the EMS interface board so it works on older iRT boilers.
It is modified according to the info based on Victor-Mo’s Github repository.
The code on the repository is intended to provide an interface to Nefit Ecomline boilers.
As the proposed modification is experimental and determined by trial and error based on a single use case, I cannot guarantee that it will work for everyone.
If the board does not work in your setup, let me know so we can see if we can do something about it.