This board is a modified version of the EMS interface or Gateway 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.
You can choose a modified version of the EMS interface board or a modified version of the Gateway board.
The modified Gateway bopard can also be ordered with a pre-programmed Wemos with the iRT firmware or you can order a complete Gateway kit which is a Gateway Standard kit with an iRT modified Gateway board.
This last option is a good choice if you ever want to revert back to EMS. The complete Gateway kit includes an additional voltage converter, 100kOhm resistor and a 3,5mm jack cable for when you want to convert to EMS.
The benefit of the Gateway board over the EMS interface board is that the Gateway board has a header for the Wemos so you don’t need to use cables to connect them.
The iRT modified Gateway board can also be easily reverted back to EMS. Remove the resistors on R21 and R22 and place a 100 kOhm THT resistor on R23.
Using the boards:
The 3,5mm servicejack on the Ecomline boiler is a mono plug with power only.
You need to connect to the bus via the thermostat wires, preferably close to the thermostat.
The Wemos needs to be powered with a USB adapter (not included).
The bigger 6,5mm plug is the iRT bus, however if you connect the Gateway there it connects the thermostat is series with the board and the thermostat doesn’t work properly anymore.
As the modification is experimental and determined by trial and error based on just a few use cases, 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.
For support go to:
If you buy one of these boards I have to manually modify an existing board.
It may take a few days before I have time to do so.
You can just order a board even if the status is ‘on backorder’.