Nest Thermostat lost WFI connection and won't reacquire.

[JoHo]

I have run into a connectivity issue on my Nest Thermostat. It has run problem free for just under two years. A few days ago it went offline and informed me it could not find the network.  It shows the following product information.  Model Display 3.7 running software version 6.2-27, Backplate Model 5.26 showing software version 2.3.51/3.1.   

Steps taken

1. Rescanned for the network. No result, none found, just kept looking. 
2.  Checked the battery voltage, Battery 3.752V; Voc 35.85V; Vin 25.98V; lin 20 mA(i) According to my understanding that should all be okay.
3. I moved the WIFI access point to within 5 feet of the thermostat and rescanned, No result no WIFI networks found.
4. Restarted the thermostat. Redid step 1 same result.
5. Turned on my hotspot and redid step 1 same result. 
6. Checked my Goggle Home device list and the MAC address it shows is the same as the thermostat but it shows the thermostat is offline. It shows it went offline January 10th. 
7. None of the other devices on the network or those that share that same access point had any problems that day or since.

My suspicion is that the WIFI is no longer working on the thermostat. That being the case, I'm not sure where to go from here, so I'm looking for suggestions. 

This is the second nest thermostat I have owned the first one I had at another home for over ten years with no problems but that was pre-Google. I currently am running both the original (at another home) and my new one on the Nest app. Until I sell my other house I am holding off switching to running my new one off of Google home.   My current one continues to operate as a thermostat, but at the price I paid I expected it to last more than a couple of years. 

[Markjosephp]

Hello JoHo,

I'm sorry to hear that you're having issues reconnecting your thermostat to your Wi-Fi network, and I appreciate all the steps you've taken. I'd be happy to take a look into this for you.

To isolate:

1. Are you getting any message codes from its network settings?
2. Manually charge your thermostat display via USB for at least an hour.
3. After an hour, put the display back to its base and check the battery level.
   1. The battery level should be at least 3.8 volts in order to hold its connection.
4. Try reconnecting to your Wi-Fi network.
   1. If no networks are found, type the network name and password manually.
5. If it is still not connecting, Go to Settings > Reset > Account Connection. Reset to confirm.
6. Once ready, check the network settings for any message code.
   1. If none, try reconnecting it again to your Wi-Fi network.

Additional steps:

1. Reset the thermostat to its default settings and proceed with installing it without connecting to the Nest app or the Internet.
2. Go back to network settings.
   1. Check for any message codes below.
   2. If none, proceed with step 6 above.

Please let me know if that helps, or if the issue still persists.

Regards,

Mark

[EmersonB]

Hello everyone,

@JoHo how's it going with your Nest Thermostat? We would appreciate it if you could share with us the information we're asking above. Also, were you able to perform the steps suggested above? We'd be glad to hear from you — We'd like to make sure everything is working.
 
I appreciate the help, Mark.

Best,
Emerson

[JoHo]

Mark,

I had done all of the things you suggested before I sent my email based on prior responses. I have received no error codes. Reset the thermostat, did as you suggested. No error codes, both times. I can see where it dropped of the network on my router around 10 a.m.  January 10th. I'm pretty sure the Wi-Fi chip failed.

John 

[EmersonB]

Hi JoHo,

Thanks for getting back to us and for sharing with us what you've done. To confirm, have you tried restarting your Wi-Fi network? To further isolate this issue, try connecting your Nest Thermostat using a mobile hotspot and create a new home structure and add the Nest Thermostat there.

Let us know how it goes.

Regards,
Emerson

[EmersonB]

Hello JoHo,
 
How's it going with your Nest Thermostat? We would appreciate it if you could share with us the information I’m asking above. Also, were you able to perform the steps I’m suggesting? We'd be glad to hear from you — We'd like to make sure everything is working.
  
Regards,
Emerson

[EmersonB]

Hey JoHo,

Just one quick final check in here since activity has slowed down. We'll be locking the thread in the next 24 hours, but if you still need help, I would be happy to keep it open. If there's more we can do, just let me know.

Best,
Emerson