Low Voc (0.18V)and Vin (0.18V) readings during operation

[TDK06]

Hi there, 

My Nest has been working great for a couple of years but recently it seems like the battery isn't charging. Going through the simple troubleshooting and manually charging the Nest from the website I have these values..

Furnace not operating

Battery = 3.771 V

Voc = 40.67 V

Vin = 37.05 V

lin = 40 mA

Furnace operating

Battery = 3.700 V

Voc = 0.18 V

Vin = 0.18 V

lin = 20 mA

What would cause my battery to stop charging?

[Markjosephp]

Hello TDK06,

I'm sorry to hear about the issue with your Nest Thermostat. The information you provided suggests that the battery voltage drops when the furnace is operating, indicating a potential issue during that mode. Here are a few things you might want to consider:

• Ensure that all wiring connections are secure and properly connected. Loose or damaged wiring could be causing a drop in voltage during furnace operation.
• Confirm that the power source for the Nest Thermostat is stable and not experiencing any fluctuations. Unstable power sources can affect the charging process. Provide with us your thermostat's power readings in the Technical Info settings and check for any wiring reports or message codes, if there are any.

Keep us posted.

Best,
Mark