I have a 10 year old Honeywell unit. If has 8 wires connected. If I
understand what I've read, the black (u1) and the brown (also u1) are
not used on the Nest. Any help is appreciated.
I installed the Nest and didn't use brown and black. It has an orange
wire (O/B) that is for the heat pump. I have a basement which is a dual
zone with the 1st floor and the upstairs (heat pump thermostat) which is
a separate zone. The app tells me t...
