Wiring - old system has 7 wires

[Thelyontamer]

I have 7 wires in my old thermostat  r, y, o, g,  w2, e, c........does this mean it's not compatible with this nest since there are only 6 slots?

[Patrick_Caezza]

@Thelyontamer 

If the Nest thermostat that you have only has six terminals then you have the Google Nest Thermostat (2020) which is not 100% compatible with your system.

Post a picture of your current thermostat's wiring here.