C wire connection at furnace

[shaunms]

I installed nest thermostat with a 4 wire furnace. I had an extra wire in the bundle. I connected that wire to the thermostat c terminal  and the furnace end to the r terminal. Is this OK? The nest thermostat seems to work find.

[Patrick_Caezza]

@shaunms 

NO!

The C wire is a common wire for the 24Vac and should only be connected to the C terminal in the furnace.