professorpaul wrote:
The new "setback" thermostats have an internal battery. Check the
instructions. My heat pumps (code issue, I believe) have disconnects
outside, as well as going through a breaker on the inside, which is
well marked.

The original thermostat doesn't have room for a battery, so its running
straight from AC, unless its BEHIND the circuit board and I have to
unscrew it from the wall first (doubtful)
The thermostat I'm replacing is a White Rodgers Model. Looks to be
original, thought the furnace is new.
WAIT! I just discovered another breaker in the furnace closet. Will
THIS turn off the thermostat even though it appears to be for the
furnace only? I don't want to just switch it off and on a bunch of
times.