Nest 3rd Gen Thermostat - No longer recognizes any network

[Pizz]

My 3rd Gen. Thermostat, no longer recognizes/can't find mine or any Network.  I installed it about 6 to 8 months ago and it worked fine.  About 2 weeks ago, it went OFFLINE and I cannot get it to find my Network.  I have two (2) other thermostats and they are working with no issues.  All computers, smart devices, phones, the other two nest thermostats, etc. have no issues connecting to my Network.  I have performed the "Troubleshooting" steps MULTIPLE times; I have reset the router MULTIPLE times; I have reset the thermostat MULTIPLE times; etc. but nothing works.  I believe it is an issue with the thermostat's Wifi receiver chip, but how do I get it replaced????

I need help,

Thanks, Pizz.

[Cblakework]

I'm having the same problem.  Nest Learning Thermostat, installed 4 months ago, worked fine until Friday.  Showed disconnected and won't reconnect to network, though testing from the network side says it has a "strong connection".  Charged it for 8 hours on USB, still not at 3.8.  Charged several more hours, rebooted both the Nest and my router, --- it connected!  But that lasted about 90 minutes, before losing connection again.  Now its low battery again.

[Pizz]

When my thermostat first went offline, it said the battery was low.  So I had the "C" wire installed at the HVAC unit circuit board's 24volt output to the thermostat's "C" connection location.  The thermostat recognizes the "C" wire input, and the thermostat now shows 3.88 volts, but it still cannot find mine or any Network.  I may directly charge it using USB, and see if that increased the voltage enough to find the Network.

[Asad000]

If your Nest 3rd Gen Thermostat is no longer recognizing any network, here are steps you can follow to troubleshoot and potentially resolve the issue

[IBHerald]

I have a very similar issue with my 3rd Gen Thermostat. I have tried multiple times to reset and it does not recognise my network. My thermostat is about 6 months old.

I need help

Ian

[AxelD]

Hi folks,

Thanks for posting in the community! Sorry to hear about your Nest Thermostats aren't connecting to the WiFi network. No worries, help is here! I'd like to ask you a few questions about your devices to gather more information:

• Does the thermostat display show any error codes or messages? E.g. W5
• Are you trying to connect to the 2.4 GHz or the 5 GHz network?

Keep me posted.

Regards,

Axel. 

[Kmeyers22]

I recently had the EXACTLY SAME issue. Mine worked just fine up until 2 weeks ago. Then it said the battery was low and disconnected from the wifi. I ended up having to take it off the wall and plug it in several times per week in order to charge the battery. Bought a Nest Power Connector, which is a C-wire substitute, thinking that would help. Charged the battery 24 hours and plugged it into the wall. It still will not connect to the wifi or the app. 

[Sunracer]

One of my Nest Get 3 thermostats showed offline in the IOS app a couple weeks ago and then the second one started showing "offline" and now they'r both offline in IOS. I've reset them a few times and both batteries show a level of 3.93 VDC. Both thermostats are ~3 years old and until 2 weeks ago they ran 100% fine. My internet and Wifi has not changed and continues to work perfectly except with these thermostats. I removed both of them from the IOS app but they still showed-up in the App section on the thermostat as being connected to my account. I reset both and now they don't show up connected at all. I'm not sure what account they're part of - I never (meant to) migrated from my Nest account to my Google account but now I can no longer login to my Nest Account even thought it was working perfectly until 2 weeks ago.

[AxelD]

Hi @Sunracer,

Thanks for posting in the Community! Sorry to hear that your two Nest Learning Thermostats are no longer able to connect to the WiFi. No worries, help is here! I’d like to gather more details about this situation:

• Does the thermostat display show any error codes or messages?
• Can your other devices find your Wi-Fi network name (SSID)?
• Are you trying to connect to the 2.4 GHz or the 5 GHz network?

Here you have an article to Troubleshoot Nest app sign-in issues, it contains some steps that might help to log in into your account.

Keep me posted.

Regards,
Axel. 
 

[Sunracer]

No error codes displayed, All 30 of my other devices are working perfectly. Tried both 2.4GHz and 5GHz to no avail. Got both of them working today as I forgot I had a PiHole running on my network and it was blocking access for the Nests. Its weird because the PiHole config hasn't changed in months but all of a sudden it affect both nests - in the last 2 weeks. Disabled PiHole and set my DNS gateway back to my Router and the Nests were then able to join the network and my app and all is good again. 

At this point it appear that all I need to do is open ports 80, 443 (which are open already of course) and 9543 to let the Nests get through my firewall. Are there any specific sites I should add to my white list? I may just add both Nests to my DMZ but that seems pretty drastic.