Well, you are talking about analog, "moded" devices (rotating knob, slider). By that, I mean, they have a single spot that they can be at any time. The slider at the top is the hottest, and at the bottom, it's the coldest.
But how does that jibe in any way with a smart device, which is almost always "modeless". It can take the temperature by requesting it. It can change the temperature electronically by sending a "change temp" sequence. But it has not way of moving a physically-moded switch.
If you're in Canada, look for ANK servers, on Ebay. Easy to deal with, and lots of parts for this sort of server.