I have a bryant thermostat right now I want to change to a honeywell rth230b the problem is that the bryant has six wires connected to it the honeywell is set up with 5 wires.

Its currently wired like this

Green g
Red r
Yellow y/y2
Blue w2
White w/w1
Black common

Is there something I am missing

Thanks let me know

Do you have a heat pump system?