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Intermittent E74 error messages

Geoellis
Community Member

After 5+ years of working perfectly, my  Nest Thermostat started  intermittently showing an E74 (No power from Rh wire) error message.  Accordingly the AC goes on and off likewise.  Any guesses as to which is the problem- the thermostat or the AC???

9 REPLIES 9

bill_in_Savanna
Community Member

No idea, but the same thing happened to me last week. I made a post but can't find it today. I even have two separate systems so tried swapping parts. The suspect thermostat and base worked on the "good" system. 

ScottFox
Community Member

mines doing this but for E75, ive reset it repeatedly tripping the breaker sometimes helps, restarting it keeps it running for a bit but it always goes off back to the error. i don't think it's the wiring in the walls from the unit itself because it does infact work now and again. what could cause this. id rather not call a HVAC repair tech on this if its the thermostat itself

Jake
Community Specialist
Community Specialist

Hey all,

 

I wanted to follow up and see I could be of any help. I found an article with some troubleshooting steps for the error you are seeing. 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. 

Best regards,
Jake

bill_in_Savanna
Community Member

Hi Jake,

There was nothing wrong with the wiring. The base of the Nest doesn't work. I had two systems, and verified that the 'bad' base did not work in either location, but the 'good' base did. Since it was not possible to replace the base, I had to replace the thermostat. I went with a different brand because of the expense for my needs and frustration that the part was no longer available in the Nest store and the troubleshooting and online assistance were inadequate (they don't consider at all the possibility of a bad base)

Ryan_G
Community Specialist
Community Specialist

Hi bill_in_Savanna,

 

Thanks for being here in the Google Nest Community.

 

We're sorry that you feel that way and we really wanted to help you further. Based on your last response, you mentioned that the base is broken. You could check out Google Store and you can order a replacement from there.

 

Let me know how it goes by replying to this thread.

 

Regards,

Ryan

bill_in_Savanna
Community Member

Hi Ryan, 

The base is out of stock in the google store and has been for the past month.  Of additional interest to others who encounter the error: My neighbor was also a Nest user and one of his 2 Nest thermostats failed at the same time mine did, likely due to the same lightening strike nearby. 

Ryan_G
Community Specialist
Community Specialist

Hey bill_in_Savanna,

 

Thanks for the reply and we're sorry to hear about what happened.

 

Based on your post, you've been using your Nest Thermostat for 5 years prior to the incident. Unfortunately, the warranty for the device has already expired and we could no longer request for a warranty replacement. 

 

You could still check out Google Store and have a look at the newest available thermostat for you.

 

Regards,

Ryan

MelbaDT
Community Specialist
Community Specialist

Hey there, 

 

I understand that Ryan's statement above is not the ideal answer you're hoping for but I want to jump in here real quick to ensure that we've got everything covered. Let us know if you have further questions in mind. 

 

Best, 

Melba

Princesss
Community Specialist
Community Specialist

Hey there,

 

Due to inactivity, I'll go ahead and lock this thread in 24 hours. Feel free to start a new thread if you need assistance with your Google Nest devices and we'd be glad to assist you further.
 

Best,

Princess