topic Nest 2nd generation disconnecting from app in Nest Thermostats

Nest 2nd generation disconnecting from app

LSFT — Fri, 05 Apr 2024 15:28:55 GMT

Nest Thermostat has been working for 9 years and recently it disconnects from Wifi and I noticed the voltage was dropped to 3.6V. I reset the thermostat and recharge the thermostat for 6 hours and saw that the voltage when charging was 3.9V. I unplug the thermostat and plugged it back into the base and saw that the thermostat about 3.8V.

The FAQs say that these are the numbers we should be seeing in the tech info

The numbers are within the info shown by Nest
If there isn't a C wire in your thermostat:

Voc: 29 to 42V
Vin: 29 to 42V when your system is not running / 6 to 7V when your system is running
Iin: 20 to 40 mA

My numbers are:

Battery: 3.723V
Voc: 38.75V
Vin: 37.90V
lin: 40mA (i)

The voltage fluctuations and from time to time it would disconnect from the app and says it's offline.

Seems like it works, but then it doesn't after some time.

Re: Nest 2nd generation disconnecting from app

aperezdeleon — Sun, 14 Apr 2024 20:23:35 GMT

Hi there LSFT, Thanks for posting in our community!

There are a few reasons your thermostat might have trouble connecting to Wi-Fi. Here's some information to help you resolve it as soon as possible:

When it's connected to the wall, a healthy thermostat battery should stay between 3.7 and 3.9 volts.
If the voltage drops below this range, you might experience Wi-Fi issues.

Your current readings seem fine. However, watch out for significant fluctuations (e.g., dropping from 37 volts to 10 volts). These could indicate a power problem.

If you monitor the thermostat and see large voltage swings, it could be due to a loose wire at the base or within the unit itself, so ensuring your thermostat is wired properly can help you out.

Let me know how it turns out

Kindly,
Angel.