I have only two ciruicts coming to the theromostat now. I had the old regular thermostat and I replaced with a programmable thermostat. The new programmable thrermostat requires 4 batteries to function. There is a power input to the new thermostat and I have only circuits to the sensors. I am trying to run power from the furnace ( I know that I can get the power) and I am not sure about the exact location to take the power in the furnace.