I need help again. The church members liked the Programmable thermostat installation in Angels Retreat so well they want one in the Church office now. The old thermostat there has 4 wires, RC, G, W, and Y. It's controlling a heater only, no air conditioning. I'm thinking I need to connect the old RC wire to the R terminal and the old W wire to the W terminal on the Honeywell RTH7400 and leave the other two not connected. Am I correct? If not, can you help? Thanks for any help you can give me!