Fing is the old fashioned (bi metallic) are not very accurate when they switch on/off and don’t carry much load. As you have electric underfloor you need to be careful as they may take load of the floor, do you have a central box/controller?Yes, of course, with an LCD and all the unused bells and whistles.
I have found ornery ones on tinternet at €3!!
they only have two wires. theses mothers have 4. So it is I hope just a question of which two to use.
Late on when I feel more up to it I'll put a pic of the back of the thing up with translation of the words on it so those who know can tell me which two wires to use. I've got a good idea but I'll let pros on here advise!
We have digital stats they can switch at .5 degree changes, but are very low voltage as they go back to a box which does the switching of solenoids for the water flow.
So yes best work out how your system works first.
J