The ATAG One thermostat needs extra power. That is why the bus input of ATAG central heating boilers has extra power. You should not connect Adam to this. Connect Adam to the OT Bus/on/off connector





However, Adam does not supply enough power to the ATAG One via the thermostat connection. To solve that, you need an ATAG One BCU adapter. You put this adapter between the Adam and the ATAG One. On the side in front of the ATAG One, extra power is then supplied to the ATAG One.


BCU:



Connection diagram: