Connecting Nest Thermostat

[cn71]

I am trying to  replace by Lennox Thermostat with Nest 4th generation. In addition to the other wires It has an extra White wire connected to To and a Red Wire Connected to Tc.  How do I handle these extra wires

[Patrick_Caezza]

@cn71 

Can you post a picture of the original thermostat's wiring here?

The To and Tc terminals on your original thermostat are for an outdoor temp. sensor that the Nest doesn't use. You can tape them off.