I recently installed a Hunter programmable thermostat. My original thermostat was a nonprogrammable SimpleComfort 2201 thermostat. I have a heat pump.

Connecting the wires was pretty straight forward except for the white and black wires.


On my original thermostat, the white wire connected to terminal W2 and the black wire connected to terminal E.

The instructions for my new thermostat has a conversion table. W2, E, X, AUX equals E on the new system. So according to the table, I could connect either or both the white wire and the black wire to terminal E. I did not think this made sense, so I only connected the white wire to terminal E and did not connect the black wire to anything.

Is it okay to leave a wire not connected to anything?

So far the system works with the auto cooling feature and the auto heat feature. I have not tested the other features yet.