:confused: Hello, I am trying to change out my themostat, I have a white-rodgers 1F58W-72, and I can tie all the wires ecept for a "X1" wire, which I don't know what it will transfer to. I have the these ready to put on my new digital thermostat, Y, W2, R, O, B, G; but nothing for the blue X1 wire. Please tell me what this wire should transfer to.

I have aWhite Rodgers 1F58W-72, and I am trying to figure out what the X1 wire is for, what does it go to, what is its purpose. I am trying to change out my thermostat for a digital one and I don't know what to do with this X1 wire. I know where to atach the B, G.O. R, W2, and the Y1, but I don't know what to do with the X1 wire, where does it go?