Im doing this with esphome, i replaced the thermostats with dht22 sensors and wired the valves via solid state relays (one for each zone) to the esp. Im using an esp with ethernet (wt32-eth01 clone), but wifi can work, if you can place it outside of the metal box of the heating system.
For control you can use a pid controller. I think there are some, which can run directly on the esp if everything is connected to the same esp.
Note: Dont use dht22 in the bathroom, it will slowly get less accurate when exposed to high humidity. Running the onewire of the sensors straight through existing 5 conductor thermostat wire/1.5mm^2 wire works reliably
Oder wenn Polizisten Datenabfragen aus privaten gründen machen