Not charging

[casperinmd]

My next stopped being charged, it is currently on a USB cable to do so b/c I have no heat.

Is this a normal thing? If the HVAC system can't keep the thermostat charged, it is just a rock on the wall.

Please advise!

[laurentbourg]

Is this a new Nest thermostat installation or did you have it for a while? What model? Do you have a C wire?

[casperinmd]

I've had it for 6 months I think. There is no C wire, but the power shows inline with what I've read on the internet.

This is a Nest E. After charging for an hour with USB, it is lasting so far. Is this normal? Can the app notify you when it loses connection to the thermostat? I'd hate to be away from home and this happen in teh winter months.

[laurentbourg]

Monitor your battery using the Technical info section in the thermostat settings in the Nest App. It should not go below 3.8V, if it does this means your battery is draining for some reason, it is usually >= 3.9V. It is possible that your Nest’s battery is defective, in which case you should call and request Google support for a replacement as your unit should still be under warranty. 

[casperinmd]

After the charge with USB it was around 3.8, but just checked and offline in my app and the nest shows 3.4 and messaged about shutting down to charge.

The RH wire has (well I forget the voltage now) but that is what will charge with no C wire right? what should that voltage be?

[laurentbourg]

Correct the R is the one that will charge, you should see between 22v to 26v AC between R and W, what voltage do you see with a multimeter? Does your furnace turn on properly when your thermostat calls for heat?