Nest thermostat blowing hot or cold wrong

[Dragonclaw]

So the Nest thermostat isn't working. It made my heat blow even when the thermostat was off. It got above 86°F in here.  The only way to turn it off was to flip the breaker.

Now it won't blow warm. I set it to heat and it's only blowing cold. 

What type of thermostat do you have? 

Nest 3rd gen learning 

Is your HVAC system a conventional or a heat pump system? 

not sure what this means. 

Would you mind sharing a picture of your wiring configuration?

When was the last maintenance check for your HVAC system?

The apartment handles it

Have there been any recent changes or upgrades to your HVAC system?

No

Does the issue happen with heating only, cooling only, or both

both

Are there any error messages?

no

Is this the first time you're activating heating since the season changed?

Yes

Link to wiring 

https://imgur.com/a/ykTgJ5D 

[maedacortez]

Hi Dragonclaw,

Thanks for reaching out. I understand that when you activate the heating, it starts to blow cold air, and I'm happy to help you with this! Thank you for sending the responses.

I have a question: Do you remember if, when you set up your Google Nest Learning Thermostat, it asked for your source type, and if you selected gas, electric, or heat pump?

If you selected the wrong source type, this could be causing the inconvenience where cool air is coming out when you call for heating.

Regards,
Manuel

[Dragonclaw]

The heat is gas and was selected as such