We are trying to install programmable thermostats that will work with our existing heat pump. Our heat pump is a Rheem model rpgb-037jaz. A friend of ours gave us a Totaline Signature Residential Thermostat P/N P374-1800. The heat pump came with the house so we can't find the details so we need to make sure that this will work. The instructions vary for the thermostat based heating and cooling stages. Is this something we can find out by the number of wires on the existing heat pump thermostat. Any help is appreciated.

Thanks!