I have a trane heat pump. There is a black wire connected to the X2
terminal on the original Trane thermostat. The install does not have a
X2 option. Is X2 compatible with another letter I could substitute?
Mark, first I appreciate your efforts in attempting to assist me. At the
present, I have gone back to the prior thermostat. Your suggestion to
run with the common disconnected is what I did and experienced the
oscillating fan on the compressor as it ...
wiring on original thermostatWiring per nest support gives error code
e79, no power on common. If I remove the blue wire, system operates but
attempts stage 2 heating. Fan on compressor cycles frequently in this
mode. Never varies on old thermostat....
