Recent update?

[Ummduh]

Was there an update recently?

I have a Nest Thermostat (basic one), that has worked fine for over a year. Today it gave me the dead battery warning and after changing those out, gave some kind of unstable power source error. I had to factory reset and now it's telling me I need to add a C wire. It's been working fine for over a year,  why is this a problem now? And I also see stuff in there about the nest power adapter, which I don't remember 

[jigsaws]

This will help

https://support.google.com/googlenest/answer/9251212?hl=en

[Ummduh]

I understand what the c wire is and what it does, what I'm asking is what was changed that all of a sudden after more than a year of proper operation it's suddenly complaining that I don't have one.

[jigsaws]

Not a recent update, power setting changes, or factory reset. This issue started after replacing the old battery. You can check if your C-wire is working by removing thermostat batteries. If your thermostat does lose its power, you will have to add another wire kit. However, consider checking the status of your power adapter. It could be the cause of the sudden changes and deterioration of the previous battery.

[Ummduh]

My point being that I never had a c wire. For over a year. And NOW it's suddenly complaining that I dont have one. Nothing has changed. A factory reset got rid of the n262 but it's still complaining I do t have the c wire. Like I said it worked flawless for over a year. Now something changed.

[jigsaws]

Okay, I get your point. The Google Nest thermostat relies on a C wire and the HVAC system to stabilize power usage. In your case, lack of C power for a prolonged period could be the cause of sudden changes. Users running on Nest without C wire experience sudden critical problems that may have taken months or over a year to manifest. https://smartthermostatguide.com/no-c-wire-install-a-nest-thermostat-at-your-own-risk/

[Ummduh]

OK, well that's seriously weird. 

Thanks for putting up with the thread. I ordered the nest power adapter thing. Doesn't make me feel good leaving the house for a week if the thermostat isn't being reliable though.

[jigsaws]

Google Nest Thermostat is currently among the best and reliable under right configurations and settings. However, heed your system's communication "missing C-wire" and the recent sudden changes as a system warning sign.  I hope you find a solution to this problem  soon.

Thank you for your positive response.

Let me know if any changes regarding the power adapter.

Thanks.