Having trouble getting new Honeywell TH8320 digital thermostat to work with my Rheem split unit heat pump. I used the manual that came with the thermostat and hooked it up as instructed, but had the orange wire left over. After some research I figured out that the blue wire should be connected to the O/B terminal for Rheem heat pumps. I also set 190 to 1 so that the changeover valve is set to heat (since it's a Rheem). Here's how the wires were connected to the old Rheem mercury thermostat that came with the heat pump. Second diagram is how I connected the wires to the new Honeywell 8320 thermostat. Any ideas on how to troubleshoot and fix this?

Rheem mercury thermostat
green >>> G
red >>> R
blue >>> B
orange >>> O
yellow >>> Y
white >>> W2
black >>> X
pink >>> L
brown >>> E

Honeywell 8320 digital thermostat
green >>> G
red >>> R
blue >>> B
orange >>> nothing
yellow >>> Y
white >>> aux
black >>> C
pink >>> L
brown >>> E