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Nest 3rd generation thermostat, e74 error

Lliniewicz
Community Member

I installed a new generation 3 learning thermostat back in 8/2021 and all of a sudden tonight it gave us the e74 error code. Nothing changed with our power or the breaker. Our internet is fine as well. We reset the breaker and the thermostat both times and it didn’t fix this issue initially. Then after about 10 minutes it fixed itself and kicked back on. Why is this happening? Do we have a defective thermostat? 

6 REPLIES 6

Lliniewicz
Community Member

It just did it again. It may seem like when it cools down to the temp we set it at then it shows the error code. Why is it constantly doing this? 

Jake
Community Specialist
Community Specialist

Hey Marysplace,

 

I would be more than happy to help you out, and ensure the error message is resolved. If you are seeing an E74 error, this would mean that there is no power to Rh wire detected. Do you mind me asking if you are showing the wire detected on the thermostat? I would recommend following the link here, as it has some troubleshooting steps that may help. Please let me know if you are still having troubles from there.

 

Best regards,

Jake

Jake
Community Specialist
Community Specialist

Hey Lliniewicz,

 

Sorry for the late reply. I wanted to follow up and ensure you are good to go. 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

Marysplace
Community Member

Jake, can you help me with an E74 error message on my nest? Power is fine, network is fine. 

Jake
Community Specialist
Community Specialist

Hey Marysplace,

 

I want to ensure you are good to go, and everything is working properly. Please let me know if you are still having trouble, as I will be locking the thread in 24 hours due to inactivity. 

Best regards,
Jake

Jake
Community Specialist
Community Specialist

Hey Marysplace,

 

It has been a few days since the last reply, and I am going to lock the thread at this time. If you have any questions, please feel free to create a new post. 

Best regards,
Jake