Nest Compatibility

[Bluejet975]

 

Is this wiring configuration compatible? 

 Last pic is at the HVAC motherboard.

[Bluejet975]

To add: there is no letter C at the thermostat or motherboard

[Tylers]

Same exact wiring.  Having trouble getting it to work. Did you have any luck?

[Bluejet975]

Yes I had no luck. I am just waiting for some one to help with an answer. I did read somewhere that the blue wire is our C Wire but I didn’t try hooking the C Wire to the blue terminal. I am not in the position to blow up my entire HVAC unit just to upgrade my system. lol