I have tried to find some basics how a standard underfloor control system is regulating the heating, but haven't, so started with checking up our own temperature control system from LK(TCS).I used Node-Red, with Raspberry Pi(RPi), sensing when the TCS applied voltage to the actuator. Since the actuator is running on 24 VAC and the input on a GPIO PIN is maximum 3,3 VDC I used a optocoupler to level shift. Schematics below
Please find another post here where I realized, using Shelly 1 and NodeRed, the regulating of the underfloor !!
