Nest replacement

[Ahusted]

I am replacing a nest thermostat with a nest learning thermostat and when I attach  the new one to the wall it will not power on to finish set up. I have checked that all of the wires are inserted properly and pulled it off and connected it to a USB to make sure the battery is charged. Please advise next steps. Thanks 

[CoolingWizard]

Just checking, does your cable have Common wire? Also, if you charge the Nest Learning Thermostat for 24-hours you should have enough power to complete the installation process. Can you post a picture of the Nest backplate showing the wires and their connections. 

The AC Cooling Wizard

[Ahusted]

Thanks so much for replying. I previously had a regular nest thermostat installed, and I installed a google  c wire power adapter on the ac unit last year. All was working perfectly. I am trying to upgrade to a google nest learning thermostat and it keeps telling me that there is no power to the c wire. 

[Ahusted]

 

[Ahusted]

 

 I can’t figure out how to move past this error so that I can see if I need to update the wire settings. Thanks! 

[CoolingWizard]

Do you have access to a multimeter so you could check power? I would check for AC power between the red wire and the C wire. Since you have a blue conductor being used for your C wire, there’s no need to have a Nest Power Adapter.  Make sure that the blue wire at your attic unit is directly connected to the C terminal on the control board.

The AC Cooling Wizard

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[Ahusted]

Thank you so much for taking the time to reply! We removed the power adapter and hooked up the c wire directly and it worked!!!! I appreciate you taking the time to help me fix this! Thank you, Thank you! 

[Markjosephp]

Hello folks,

I appreciate your help, @CoolingWizard.

Great troubleshooting, @Ahusted! I'm glad to hear that it's sorted out. I wanted to ensure that everything was covered here. Please let us know if you have any further questions; otherwise, we'll close the thread in 24 hours.

Regards,

Mark