Blowing cold air when set to heat

[Smitty000277]

I just installed the nest thermostat and set it on heat mode and it is blowing cool air not warm air. 
 

Previous thermostat wiring

 

 

[Patrick_Caezza]

@Smitty000277 

It looks like you have it wired correctly.

Double-check to ensure the white (W) wire is fully inserted into the base terminal.

Swap the white (W) and yellow (Y) wires and set the thermostat to cool. Does it provide heat now?

Connect the White (W), Red (R), and Green (G) wires together and see if the heat turns on. I there still isn't any heat then your system has a problem.

BE SURE TO POWER THE HVAC SYSTEM OFF BEFORE MOVING ANY WIRES.