I have an old honeywell thermostat with a dial and I am trying to replace it with the honeywell RTH111 but I only have white and black wires coming from the wall and not sure how to hook it up! The manual says on connecting it the is 1 diagram that shows Y- & G- and a different on that has r-&w- please help me figure out where the black and white wire go to make it work, the display just says heat on and only blow cold air then shuts off