Replace Honeywell G/Y/ OB /R with Nest Thermostat (not nest learning not nest E )

[SharonL778]

My house uses an old gas furnace for heating and an air conditioner for cooling. No heat pump as far as I know. I follow the nest thermostat installation instruction carefully, twice, but the HVAC system still blows hot air not cooling. Pls advise if the old wire OB is an issue as it is for heat pump(?) or something else. Thank You. 

[SharonL778]

 

[SharonL778]

I got it figured out. Post here in case helpful to you. I used to have a OB wire. At nest thermostat setting, I changed from default O to B, that stopped blowing hot air! See attached 

 

[EdmondB]

Hello SharonL778, 

Thanks for posting here in the Community, I’m glad to hear that you’re able to activate your cooling system. As we got our resolution here, I'm going to mark this one as resolved. Please feel free to open up a new thread if you need assistance.

Thanks,
Edmond