I have upgraded my home HVAC system to a Trane XL17i Heat Pump (4.0 ton)
and a Trane TEM6 SERIES VARIABLE SPEED FOUR-WAY CONVERTIBLE 48K AIR
HANDLER (TEM6A0C48H41S). I would like to reinstall my Nest Learning
Thermostat 3rd Gen and have 3 questions:1...