I bought a digital thermostat to replace my White-Rodgers thermostat. Stupid me didn't mark what wire goes where. The thermostat I bought I can't use because I have a heat pump with back up heat. I do know that only 7 wires were connected. The brown wire was not. Can you help me to re install my trusted White-Rodgers thermostat? I'm not sure which terminal the black wire goes.