I just installed a Honeywell RTH6450 thermostat and on the packaging it says that it has the ability for auto chageover from heat to cool and vise versa. The only problem is that when I took my old thermostat off, the blue wire wasn't connected to anything and wasn't even stripped. When I go and look at the opposite end of those wires on my Trane XE80, the blue is also not attached to anything. I'm guessing that the ability to auto changeover depends on the blue wire being connected? It's pretty obvious where to connect on the thermostat, but not so much on the Trane. Any ideas?

It's pretty obvious where to connect on the thermostat,


Tell us,we`re not there,, so where do you think the blue wire should go on the tstat?