Google Nest E with C wire runs on batteries and dies

[AlvinTheTostig]

The C wire is wired correctly. It shouldn't be using battery power for anything.

The batteries that shipped with the unit died within a day.

I replaced them with new Duracells - and they died about 2 months later.

Why is this thing using batteries, when it's connected to A/C power via C wire? I've read one account of someone with this problem, and he replaced it with another Nest E and now has no problem. 

[Jenelyn_O]

Hi AlvinTheTostig,

Thanks for reaching out. I'm sorry for the trouble this has caused you. The Nest Thermostat receives power from your HVAC system. It also uses 2 AAA alkaline batteries as a backup, or to supplement if your system can’t deliver enough power. Let's sort this out. Do you see any messages or codes on your Nest Thermostat? Could you please take a photo of the wires you have on your thermostat? Also, please check your thermostat power read out.

You can follow this guide:

1. Go to your thermostat Quick View menu.
2. Go to Settings.
3. Look for Technical Info.
4. Choose Power. 

If you have a voltmeter, please check the voltage of your C wire.  

Best,

Jenelyn

[zoeuvre]

Hi there, 

I want to check and see if you are still in need of any help. Please let me know, as I would be happy to assist and answer any questions you may have.
 

Thanks,

Zoe

[Jenelyn_O]

Hey AlvinTheTostig,

I'm just checking in to make sure that you've seen our response. Please let us know if you have any other questions or concerns, as I'll be locking this thread in 24 hours.

I appreciate the help, Zoe.

Regards,

Jenelyn