I'm sorry to hear that your Nest Temperature Sensor keeps going offline. I'd be happy to take a look into this for you.
The sensor can't work in the desired room if the sensor is over 50 feet away or has significant wireless or physical interference that interrupts the communication between it and the thermostat.
To test the sensor connection, please perform the following steps:
Please have a look at this guide to troubleshoot when the temperature sensor went offline and let us know if you need more help:
I wanted to check in and see if you managed to see Mark's post. Please let me know if you have any questions from here. I would be happy to assist, and make sure you are good to go.
If I reset the thermostat the sensor works in the room where I want it and where I have used it for at least a year. The next day it’s offline. What can I do so that I don’t have to reset every day?
Thanks for the update. We need to isolate the issue by moving the Nest Temperature Sensor closer to your Nest Thermostat and observe it for 48 hours to check it the issue is caused by interference.
Keep us posted.
I think the temp sensor may not work anymore even though it appears to be online after resetting the thermostat. I reset the thermostat, the sensor was online, and I took a hair dryer and warmed the sensor up but the temperature reading for the sensor stayed at 70 degrees (and I think the temp in the room was 68). Could it be I need a new sensor? What is the typical lifetime of these sensors?
It's me again. I wanted to stop by and see how I could help.
The Nest thermostat's battery level can also affect the Nest Temperature Sensor's connectivity. Similar to Wi-Fi, the thermostat disables Bluetooth when the battery has no charge. If the sensor's battery is low or falls below 3.65 volts, the sensor can't transmit the temperature data to the thermostat.
Could you please check your thermostat's battery level status under "Power" in the technical information on its settings? Also, ae you still using the factory-supplied original batteries for the temperature sensors?
I'll look forward to your response.
The battery level is 3.74 and I put a new battery into the sensor, didn’t help. I just went and bought a new google nest temp sensor and it works in the room where the one that stopped working was being used. How long should these temp sensors work?
Uh oh! I'm sorry to hear the issue still persists. Thanks for letting me know what you've done.
It lasts depending on usage, but the Nest Temperature Sensor’s battery can last up to 2 years. Also, we've created a case for you. Your issue has been escalated to our upper support team. Be on the lookout for an email from us in your inbox soon.
I wanted to check in and see if you managed to see Mark's post. Please let me know if you have any trouble getting in touch with our team from here, as I want to ensure you are being helped.