Nest - Battery

[Langleytheys]

I have a nest thermostat at my cottage that I use to turn on the heat before arriving. 

Recently I receive a notification that the battery was dead and it was offline. I had a neighbour go over and replace the battery but it soon died again. I do have a C wire hooked up proving power.

My question is - is my furnace still working without the batteries, as I have a c wire installed? Or do the batteries provide instructions to the furnace to control the temperature and it is now likely shut off?

[Jenelyn_O]

Hi Langleytheys,

Thanks for reaching out and for being a step ahead of us. Batteries are responsible for your Nest Thermostat to stay on, and for you to adjust your temperature using the device whenever you want, to stay comfortable. 

The C wire should provide consistent power to your thermostat and prevent the backup batteries from draining. If you repeatedly get low battery messages from your thermostat, or if there’s another power-related message, you may need to check your C wire connection.

• Make sure the wire is fully inserted into the thermostat connector.
• Turn off power to your system and check that the wire is connected to the C terminal on your system’s control board.

Best,

Jenelyn