No C wire connected to current thermostat, but blue wire is available

[Mooremeatloaf]

 

 

 

My old thermostat has wires plugged into G, W, Y, R and then there is a jumper from R to RC. I’m trying to figure out how to get this to work with the nest thermostat. When I plug in the G, W, Y, and R wires into the corresponding slots on the Nest, it keeps telling me that the C slot isn’t getting power. 

There is a blue wire in my cluster that currently wasn’t being used on my old thermostat. I tried plugging that into the Nest but got the same error. Using my electronic tester it confirms that the Red is carrying a power load but Blue is not.

I went up to my control panel and there is a blue wire that is not connected, but it looks strange that there are 2 sets of wires. Can I double up the blue wires where the C is on the control panel? They Y has two wires in the control panel. I assume the set of wires with the blue not connected is the one to my thermostat, I’m not sure what the other set is. 

Any recommendations on what I can do?

[CoolingWizard · Accepted solution]

@Mooremeatloaf , at your air hand or you can indeed hook up that second blue wire with the other blue wire that’s hooked up to the location As the other blue wire; this is your Common.  You will notice the second cable only has a two yellow wires attached to Y, and the blue wire attached to common. This cable goes outside and this is what turns on your air conditioning compressor. If you attach the blue at the air handler, and the blue wire at your Nest to C, it will be happy and see the Common Power. 

AC Cooling Wizard

[Jenelyn_O]

Hi folks,

Thanks for posting in the Google Nest Community forum. I just want to check if you managed to see the response above. Please let us know if you still have questions or concerns, as we'll be willing to assist you further. 

I appreciate your help, @CoolingWizard.

Best,

Jenelyn

[Jenelyn_O]

Hi Mooremeatloaf,

I wanted to follow up if you still need help. Please let me know if you’re still having any concerns or questions from here, as I would be happy to take a closer look and assist you further.

Thanks,

Jenelyn

[Mooremeatloaf]

Totally worked. Thank you!

[CoolingWizard]

@Mooremeatloaf , if you get a moment, please go to the message I sent that worked and mark it RECOMMEND THIS ANSWER.  This help others as well. 

AC Cooling Wizard

[Jenelyn_O]

Hi there,

Thanks for the update! I'm glad to hear that it's now working. Please let us know if you still have questions or concerns, as we'll be locking this thread after 24 hours. 

I appreciate the help, @CoolingWizard.

Cheers,

Jenelyn