Nest thermostat

[monte007]

Nest thermostat will no longer connect to wifi

[David_K]

Which model of thermostat do you have? You can check here:

How to tell which Nest thermostat you have - Google Nest Help

First thing I would check is that you're not experiencing a well known issue:

Troubleshoot a Nest thermostat w5 code - Google Nest Help

If not, try these steps:
Nest thermostat is offline - Google Nest Help

After several minutes, can your thermostat see any Wi-Fi networks at all?