We have had our third thermostat installed.
The first one worked for 2 years and then quit. Technically it did work for that long as it was installed in our basement bathroom that overnight company uses so was used only a few times a year. Our electrician who installed it, ordered a replacement thermostat and it never worked. We then hired a different electrician a year later and ordered this last (third) thermostat ourselves. The new electrician could not get the floor to warm up either so the only solution we are told now would be to rip up the tile floor and start over!! ... Well, that isn't going to happen.