Help for a noob who’s controlling multiple under floor heating mats

Hi all, brand new to HA and have got as far as controlling lights.
Next is to get rid of three separate thermostats for three rooms that control under floor heating.
I’m looking at simple out of the way switch where the thermocouples connect and feed back to HA which will be programmed to switch the floors on and off as pre programmed.
Would really appreciate any ideas on achieving this.
Thanks in advance