I replaced all three of my old thermostats with nest. The old ones all worked fine.
Two of the three I replaced are working fine. The third one returns error "no power". When I put the old thermostat back on, it still says "no power".
Q1. How do I found my FAU to this thermostat
Q2. Why did the power go out on this thermostat
NB: Edison put devices on my A/C compresses so they could disconnect them in case of power shortage
