[jsb5717]

When you pull the exterior panel you can see it. It’s screwed in with 2 screws and should have 3 wires attached. Just unscrew it and pull it out of it’s opening far enough to see the contacts. If there’s lint or dirt in the way it should be fairly obvious. Just blow or brush it out. Make sure it looks clean and moves freely. Reinstall it and try again.

You can look up videos on the subject as well to make sure you know what you’re looking for. This troubleshooting step is a very easy one to check. There is an on/off switch also in that vicinity when you pull the cover off. Make sure it’s on.

If that doesn’t solve it then please report back on exactly what it does when you first set your TStat.