Nest Thermostat Blowing on Heat blows cold air

[Maverickman1984]

I had a honeywell thermostat that was blowing perfectly and then I switched to Nest thermostat and connected wiring as demonstrated below..AC was blowing well but today had to turn on heat and that started to blow cold air.

Nest Wiring

Honeywell Original Wiring

[AllipoJ]

I'm having the same issue.  House got cold this weekend, Turned on the heat and it activated the condenser and the ac was running.  I checked the wires, double checked again, also verified  the wires in the furnace.  The thermostat simply is broken

[AllipoJ · Accepted solution]

I had to call for help.  I spoke to Chris and he was awesome.  We had to reconnect the wires and reset the app and thermostat.  Now I have heat without the condenser turning on.  🙂

[Sami289]

just disconnect the Y wire, reset and see if it works. It worked in my case