I was noticing that you have two wires going into the W terminal. Now when you have a heat pump the W terminal is used to call for auxiliary or emergency heat. Yours has a white wire and a black wire both terminated in your W terminal. What I don’t know is if you have auxiliary heat and emergency heat or if they’re both simply wire together. It’s kind of unusual to have two wires in one terminal.
here are the normal conventional heat pump, wiring, terminals and functions:
R, Rc and Rh, this is your power input terminal. Rc is cooling, Rh is heating. The power is 24VAC
Y, Y1 this is the compressor control relay. When the thermostat energizes this wire the compressor turns on.
G this is the fan relay. When this wire is energized by the thermostat, it turns on the fan.
O/B this is the heat pump change over valve. This changes B models to heating mode and O models to cooling mode. You have an O model heat pump.
W, W1 and W2. on heat pumps these can sometimes be used to turn on auxiliary heat or emergency heat
Do you have access to the forest air handler so we can see with the black wire and the white wire or connected to?
AC Cooling Wizard
Now, if you have both auxiliary heat and emergency heat, we will need to use a nest learning thermostat.
NestPro, Google Pro, Mechanical Engineer and HVAC service company owner.
