What to do with my W2 wire

[Dmick]

 I have a W2 wire and my NEST thermostat doesn't have a spot left (only 6 terminals) with O/G being the only one left. I assume the furnace might be a 2 stage blower seeing that it is new. After install everything works  but will the furnace work properly when called upon. Thanks!

[David_K]

Sounds like you have the Nest Thermostat (2020) model, which has a programmable */OB connector for this purpose. Here's what the wiring should look like (old to new). Does this not match what you're seeing?

Y - Y
G - G
C - C
W2 - */OB
W - W
R - R