Problems with Nest Thermostat

[JLanier]

I purchased two Nest Thermostats and installed both of them.  They have identical wiring.  Both units activated and connected to my WIFI.  One is activating the A/C unit it is connected to and cooling its zone.  The other shows a display that seems to indicate it is working and yet it is not turning on the A/C, and I keep getting low battery notices.  I have checked to make sure that the C Wire is fully locked in place and I have restarted the thermostat three times.  It always starts up and connects, but still does not turn the A/C on.

I have entered two cases with Google online over the last week, but have not had any response.  The old customer service number has a message that it is out of service.  How can i get in touch with someone at Google to help me troubleshoot this issue.  I have now gone since Feb. 26th without cooling in that zone and the room temperature is hovering over 80.

[Patrick_Caezza]

Can you post a picture of each original thermostat's wiring and how you have the Nests wired?

Do you have two separate systems or just one with a zone controller?

If you have a zone controller then post a picture of its wiring too.

[JLanier]

 Thank you. I have two zones. I replaced two Carrier Edge thermostats with Nest Thermostats. I did not save my photo of the old wiring, but filled instructions per Google home. Both of the Nest started up and connected to WiFi and to each other. Both displays indicate they are working, but one of them is not starting the a/c unit it is linked to. I switched out the units, and both work in the one zone but not the other. 

[Patrick_Caezza]

@JLanier 

If you switch the units and the problem stays at the original location, you have a problem with the HVAC system.

Double-check your wiring and ensure all wires are fully inserted into the terminals, and you have straight, shiny copper on the end of each wire.

Didn't you answer if you have a zone controller or not?

If you do, please post a picture of its wiring.

[JLanier]

Patrick,

Two separate zones - no controller.  I redid the wiring on the problem unit one more time, checking that all wires were clean and appropriately inserted and secured.  Then ran the thermostat through another reset.  Still no connection between thermostat and a/c unit.  I will call in my HVAC technician.  I appreciate your help in confirming the troubleshooting steps I had taken as a first step.

Lanny

[aatienza]

Hey JLanier,

Checking in — were you able to reach out with your HVAC system to fix your thermostat? 

I appreciate the help, Patrick_Caezza.

Thanks,

Archie

[EmersonB]

Hi everyone,

@JLanier, we wanted to follow up and see if you are still in need of any help. Please let us know if you are still having any concerns or questions from here, as we would be happy to take a closer look and assist you further.

I appreciate the help, Patrick_Caezza and Archie.

Best,
Emerson

[EmersonB]

Hey JLanier,

Just one quick final check in here since activity has slowed down. We'll be locking the thread in the next 24 hours, but if you still need help, we would be happy to keep it open. If there's more we can do, just let us know.
   
Regards,
Emerson