Learning Thermostat Blinking Orange/Green, Clicking, No Display — Power Connector Installed

[Sidhant]

Hi everyone,

I’m having a major issue with my Nest Learning Thermostat (3rd Gen) that has suddenly stopped working after running perfectly for over a year.

Symptoms

• Thermostat blinks orange and green, with a faint clicking/ticking sound
• The screen is completely black and will not turn on
• Thermostat will not show any information, even after charging externally for multiple days
• The thermostat cannot be added back in the Nest app because the display never lights up

System Setup

• Dual-zone HVAC system
• Two Nest thermostats (Zone 1 & Zone 2)
• The other thermostat works fine when connected to either zone — so wiring and zone board appear functional
• This thermostat seems to be the only failing component

Troubleshooting Already Done

1. Removed and externally charged the Nest for multiple days
2. Installed a Nest Power Connector to ensure stable power
3. Verified wiring on the zone controller
4. Swapped thermostats between zones — the other thermostat works in both locations
5. Tried rebooting and re-adding to the Nest app, but the screen stays completely off
6. Verified that the HVAC system itself is functioning

What I Need Help With

At this point, it appears the thermostat hardware has failed.

I’d appreciate:

1. Official troubleshooting steps to confirm hardware failure
2. Guidance on how to request a replacement unit, including any warranty or out-of-warranty options
3. Whether the blinking orange/green with clicking is a known internal failure mode

Thank you in advance for your help — I’d really like to get this resolved before the cold weather hits.

[RW82]

Having the same issue so am interested in this thread / responses. Mine thermostat turns on when laid flat but turns off if handled suggesting it’s a connectivity issue between base and front. 

[EduardoN]

Hi @Sidhant,

Thanks for contacting the community! I understand that your Nest Learning Thermostat (3rd Gen) is currently experiencing symptoms like the display not turning on, blinking lights, and other issues. I appreciate the time you took to troubleshoot the thermostat. Regarding your HVAC specifications, you mentioned that you installed a Nest Power Connector and have another Nest Thermostat that is working fine.

At this moment, I can confirm that the issue is not the HVAC system; the issue is the thermostat itself. Therefore, the team would like to learn more about this behavior. When you get a chance, please fill out this form and let us know when you’re finished. We’ll have someone reach out to you via email from there.

@RW82, I appreciate your comments aboutt this situation!

Keep me posted.

Best regards,
Eduardo

[Sidhant]

Thank you Eduardo, I’ve completed the form. Awaiting reply via email. 

[EduardoN]

Hi @Sidhant,

Thank you very much for the confirmation. If you have any questions or require further assistance, please do not hesitate to contact us. We would be happy to assist you!

Best regards,
Eduardo