Error E194 but AC is working.

[Lexi1st]

 

We’ve had this thermostat installed for 3.5 years and it has worked seamlessly. Today it threw code E194 no power detected R wire required. The R wire is in. The AC unit is running and cooling. Yet I can’t get the thermostat to actually work. Now what???

[Jenelyn_O]

Hi Lexi1st,

Thanks for posting in the Google Nest Community forum. Please share with us your Nest Thermostat power readout by choosing the Technical Info. I noticed that you have a blue wire, if that is your common wire connect it to your thermostat C terminal (Ensure to turn the breaker off first before touching any wires). Also, you can visit this support article for the list of troubleshooting that you can try. 

Please let me know how it goes.

Best,

Jenelyn

[Jenelyn_O]

Hi there,

Checking if you still need help. Please let me know, as I'll be willing to assist you further. 

Thanks,

Jenelyn

[Jenelyn_O]

Hey Lexi1st,

Due to inactivity, we'll go ahead and lock this thread in 24 hours. We'd be glad to help you further so if you still need assistance, feel free to start a new thread.

Regards,

Jenelyn