Another noob question: see the attached image of my thermostat. Would it be possible to switch it for a smart one? What would I have to check? If it is possible, what would you recommend? If is don't want any 3rd party app or account?
I looked into this a few years ago. At that time, if you had a "c wire", there were several options that would work directly with HA.
I don't have a C Wire so that didn't help me.
Without a c wire, I was only able to find a single option. A "Sensi" brand that could run on batteries, but wouldn't work directly with HA. Tou had to control it though Amazon Alexa or through their app. Neither option turned out to be particularly reliable.