I am changing to a new thermostat and all wires have been connected except the new thermostat does not have a screw for the w-1 wire. What does this control and where does it go. Changing from a york to a new honeywell thermostat for a heat pump

Uh-oh... you may not have the proper thermostat for your system. Heat pump systems with electric auxiliary heat require a 2-stage heat, 1-stage cool minimum.