Im replacing an old mercury switch type thermostat in my house with a newer digital one. They are both dual control units for AC and Heat BUT...it is controlling the heat only and I have seperate T-stat for the AC.
My question is this, I have the standard Red/Black wires to the Furnace control unit to trip the heat but there are also a pair (white and black) of wires carrying 24 volts to the T-stat directly from a transformer downstairs. The new T-stat says the 24 volt wire is "optional" since it also runs on batteries but seems to only mention one wire in the wiring instructions. Can I bypass (remove) the 24 volt power and run the two wires only? Also, why dont the instructions mention the other wire from the 24v source?
My question is this, I have the standard Red/Black wires to the Furnace control unit to trip the heat but there are also a pair (white and black) of wires carrying 24 volts to the T-stat directly from a transformer downstairs. The new T-stat says the 24 volt wire is "optional" since it also runs on batteries but seems to only mention one wire in the wiring instructions. Can I bypass (remove) the 24 volt power and run the two wires only? Also, why dont the instructions mention the other wire from the 24v source?