I have a southern California two-story home built in the late 70's. Its a single zone system with both heating and AC. The thermostat is located downstairs. In the summer the upstairs gets too hot and in winter the downstairs is too cold. Normally the system is either set to heat or cool depending on the season.
I'd like to place a second thermostat upstairs (wireless) and pair it with the hard-wired one downstairs. That way the "system" can tell the actually max/min of the house temperature.
Is there any thermostats out there to do this? Would it even work?