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nest will not power up

Community Member

my nest thermostat will not power up.... it just flashes yellow at the top little light... not sure why it wont turn on 



Silver Product Expert
Silver Product Expert

IN order to help you, please provide additional information. 
Is this a first time new installation?

Did you have a picture of the old thermostat and the wires?

Can you upload a picture of the nest back plate with the wires installed?

Did you have a C wire installed in your old thermostat?

Ken, The AC Cooling Wizard 

NestPro and HVAC company owner

Hi folks,

I appreciate the help, Ken.

@dwpeterson5, It appears that your Nest Thermostat isn't getting enough power from your system. I did find a helpful article with some troubleshooting steps for when your device is not turning on.

Please let me know if that helps or if the issue still persists.

Best regards,


Hi folks,

Chiming in to see if you still need assistance with this. Let us know if you have additional questions ― we'd love to help.


Hi everyone,

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, I would be happy to keep it open. If there's more we can do, just let me know.