Update from my post this summer. I had gone into advanced settings and
had the furnace running without the fan, and I also disconnected the air
conditioner wire from the baseplate of the next thermostat and it's
been. Running fine since. I can't quit...
I got my nest through comed last winter. Installed it before Christmas.
It kept trying to test the A/C, but in winter the a/c doesn't want to
work. So I put the old thermostat back on because we were in a-20 cold
snap. Switched it back in the spring ...
