Google Next Learning Thermostat cooling way past set temperature

[ndolce]

Hello,
I have a dual zone AC system with one Nest Learning thermostat upstairs and one downstairs. Occasionally, the upstairs thermostat will cool way beyond where the thermostat is set at. For example, it was set to 73 today and cooled to 66. Is it possible the thermostat is bad? They were purchased 3 months ago. 

Thanks,

Nick

[ovidioj]

Hello @ndolce,

Thank you for posting in the community. 
It's frustrating when a thermostat doesn't function as expected. I appreciate your effort. To troubleshoot this issue, please provide the following information:

• When did the issue start?
• Are there any error messages? If so, what are they exactly?
• Does the issue happen on heating only, cooling only, or both?
• Have there been any recent changes or upgrades to your HVAC system?
• Is this issue specific to the upstairs thermostat, or are both thermostats experiencing similar problems?
• Can you send me a picture of the thermostat wiring? 

While I gather more information, you can try the following:

1. Restart Devices: Power cycle your Nest thermostats, router, and HVAC system.
2. Check Thermostat Settings: Verify that the upstairs thermostat is set to the correct mode (cool) and the target temperature is appropriate.

Please keep me posted; I will be more than happy to help you. Thank you. 

Regards, 
Jorge 

[ndolce]

Hello,

This issue started about ten days ago. There have not be any error messages. The issue has only be related to cooling thus far. There haven't been any recent changes to the HVAC system. It only blows cold air nonstop through the upstairs. I've attached the wiring below. I tried power cycling everything and that hasn't resolved it. Thank you!

[catheryn]

Hello!

I apologize for the inconvenience caused by your Nest Thermostat. Let's troubleshoot based on the following steps:

• Check the Energy History: Review your thermostat's energy history to see if there are any unusual patterns or anomalies.
• Check Auto-Schedule: Verify if Auto-Schedule is enabled. If so, temporarily disable it to see if it affects the issue.
• On the Nest app:
  • Select Nest settings.
  • Choose Auto-Schedule.
  • Turn off Auto-Schedule.
• On the Google Home app:
  • Tap on the name of your Nest thermostat.
  • Tap on Temperature preferences.
  • Under Nest Sense, tap on Smart Schedule.
• Perform a wire swap: This may require turning off the power at the breakers.
• Inspect the C terminal: Remove the Nest thermostat's display and check if there's a wire connected to the C terminal.
• Use the Nest Thermostat Compatibility Checker: Refer to this tool for guidance on compatibility and troubleshooting.

If you continue to experience issues after following these steps, please let us know, and we'll explore further solutions.

Thanks, 

Catheryn.

[ndolce]

Hello,

Turning off the auto schedule actually fixed the problem but where do I go from here? The whole point of buying this thermostat was the scheduling and learning feature. If there's something wrong with the device, how do I seek a replacement?

Thanks,

Nick 

[jenniffert]

Hi @ndolce,

Thanks for following up! 

I’m glad to hear that the inconvenience was resolved in the meantime. As this is a new Nest thermostat, it may take some time to learn your preferred temperature settings for day and night.

To help the thermostat learn faster and prevent unwanted temperature changes, I recommend creating a schedule. If this doesn’t resolve the issue, you can try resetting the “schedules” option, recreating the schedule, and turning on "Auto-schedule” again. For instructions, see this article: Restart or reset a Nest thermostat.

For reference, you can check out these articles: Change the temperature to update the thermostat schedule and Temperature schedules for the Nest Learning Thermostat.

Keep me updated.

Best regards,

Jenniffer