A thermostat that seems dead is not always the actual problem

https://donovanddac443.hexaforgey.com/posts/why-salt-lake-city-s-hot-summers-and-cold-winters-put-extra-demand-on-your-ac

A thermostat that seems dead is not always the actual problem, because control issues can also come from wiring or system-side faults rather than the thermostat itself.