I tried to install it one more time and it still does not work - same problem as noted earlier. I know I wired it properly so I don't understand why it doesn't work??

I ran down the wiring, but am not sure this is going to be helpful as I can only tell you which termal was linked to which color wire in the air handler (I didn't open it up nor did I open up the panel on the heat pump). Here goes:

The C (X1 on the old teromstat) and Y terminal wires bypases the airhandler and go to the heatpump.

The O/B terminal wire also bypasses the airhandler and goes to the heat pump. [Don't know if this is meaningful or not but on the second unit (the one on which the new termostat works) the Blue wire from the air handler also is attached to the O/B terminal wire while on the non-working unit, the blue wire off the air handler is wired directly to the heat pump via a separate wire- it is not wired into the O/B termial wire as on the other unit.]

The W2 terminal wire goes to the heatpump but is also conected to the violet wire on the airhandler

The G terminal wire is connected to the Orange wire on the airhandler

The R teminal wire goes to the heatpump but also is connect to the Red Wire on the airhandler (note that it is not connected directly to the red airhandler wire but first the wire runs to something that someone has lableled in black ink next to the unit "FIrestat Restart" and from there the wire goes on to be connected to the red wire on the airhandler).

Any suggestions? If not, looks like I will have to pay for a service call. Thanks