E79 error after 2 weeks working fine

[stifland1]

I installed 3rd generation nest to replace my overly complicated and crappy Trane thermostat...although system is a Carrier.

I came home today to find the E70 error no power to C wire.

I cut off 1/4 inch / restripped wire and reconnected.  Same error.

The AC is working but I can't see the temp controls on the App or the thermostat.  Well, I say its working. Just got home and found error and fan is working anyway, we will see if it cools down.

Any ideas?

[Ryan_G]

Hi stifland1,

Thanks for reaching out here in the Google Nest Community.

The error showed is an indication that your Nest Thermostat is not getting any power from the C wire, or it doesn't detect the wire connected to it. Check the main terminal block and inspect the fuse from the HVAC unit.

I hope it helps.

Regards,

Ryan

[EdwardT]

Hi stifland1,

I wanted to follow up and see if you are still in need of any help. Please let me know if you are still having any trouble from here, as I would be happy to take a closer look and assist you further.

Thanks,

Edward

[Jhonleanmel]

Hi everyone, 

I'm just checking in to make sure that you've seen our response. Please let us know if you have any other questions or concerns as I will be locking this in 24 hours.

Thanks,
Mel