My nest is connected with two wires (boiler). I don't have a "C" wire
but I've monitored the battery voltage and it's always been above 3.8v.
Some folks on reddit mentioned the sensor offline issue is due to
thermostat battery voltage but I doubt tha...
Same issue here. I was able to get the sensor to reconnect by resetting
the thermostat but two days later the sensor is offline again. The
sensor is 8 feet away. Nest battery voltage is 3.86V.
