I’m getting ready to hook up the floor heat in my new house. I’m going to use slab temperature probes in the concrete to measure the temperature and set the system based on that temperature. I want to pick thermostats that will send the temperature from that slab sensor (will be hard-wired into the thermostat) to HA. I currently have Venstar T7900s in my house, they report to HA but I found that they only report the temperature from the onboard sensor, not any remote sensors.
Does anyone know of a thermostat that plays well with HA and will send HA the remote temperature sensor reading as the main temperature?
I think you will have a hard time finding thermostats that have external wired sensor option.
I suggest you go for a seperate sensor controller and let HA manage the valve from the reading on that.
I guess an ESP device can do that easily, maybe with ESPHome.
I agree with WallyR, and ESP32 or ESP8266 with a probe is probably your best bet. You could take multiple individual sensor readings and average them per room.
It shows that you can daisy chain many of these sensors together and it will average them. The challenge would be how to embed the ACC-TSEN into the slab.