E74 cod. No power rH wire

[Terpfan11]

For 8 months my nest thermostat has working perfectly fine. Now it has the e74 error code and nothing is working. I’ve charged the thermostat, detached and reattached the rH wire. Not sure what else to do. It’s summer so ac is sort of a requirement.  

[Jenelyn_O]

Hi Terpfan11,

Thanks for reaching out. I'd like to know more about it. A few questions: did you experience any power outage in your area recently? Do you have a C wire? Please share with us the photo of your Nest Thermostat wiring. Also, please check your thermostat power readout by going to the Technical Info. Ensure that your breakers are turned on. If you’ve had any construction or maintenance done on your home, your breakers might still be off.

You can follow this guide as well to isolate the issue:

1. Turn the power breaker off.
2. Remove the red wire from RH.
3. Ensure that the wire is flat and straight.
4. Move the red wire from RH to RC terminal.
5. The terminal tab should be pressed down.
6. Make sure to turn the breaker back on.

Check if the issue persists.

Best,

Jenelyn

[Jenelyn_O]

Hi there,

It's me again! I just want to check if you managed to see the response above. Were you able to try the troubleshooting steps I provided above? Please let me know how it goes.

Thanks,

Jenelyn

[Jenelyn_O]

Hey Terpfan11,

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'll be locking this thread in 24 hours.

Regards,

jenelyn