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Nest Protect - Sensor Failure/Sensor Restored Recurring Error

Community Member

I have a 2nd gen Nest Protect in my guest bedroom that is throwing a sensor failed/sensor restored error at 7:30pm. This happens approximately every two weeks. What could be causing this? The device itself glows green every night, is clean, and has fresh batteries. Do I need to get the device replaced under warranty or is there something else I should try?


Community Specialist
Community Specialist

Hi Ltovey,


Thanks for reaching out. I'd like to know more about it. What type of sensor failure did you encounter? Is it Smoke sensor failure, Carbon Monoxide (CO) sensor failure, Light ring failure, or Silent failures? 


A few more questions: 


  • Did the issue happen out of box or after installation?
  • How long did the issue occur after the installation?
  • Are there any nearby sources of steam, smoke, or any other visible vapor?
  • Any previous events with Nest Protect such as, false or legitimate alarms, chirps, or other unexpected behavior?
  • How were you notified of the sensor failure?
  • Does the reported sensor failure correspond with any recent construction, cleaning, or other activities in the house that could have introduced large amounts of dust or foreign particles into the environment?
  • Is the Nest Protect near any air vents, fans, windows, or other sources of air flow that could bring dust or foreign particles into the detection chamber?
  • Where is the Nest Protect installed (room, ceiling, or wall)?
  • When was the last audio test?




Community Member

Hi Jenelyn,

I just became aware of this issue after checking the nest app, so I believe it would be a silent failure as it still glows green at night. All of my protects were installed in October 2022, and just started in November 2023. There are no sources of smoke, vapor or steam, and there has been no construction, cleaning or modifications to the room or area around the protect. The only unexpected previous behavior with this protect is that after an extended power outage, it takes a manual test to get it back online/showing that it's connected to the house power.  There are no vents or windows or sources of air nearby. This protect is installed on a guest bedroom ceiling, and is within 6' of another protect in the hallway that reports no issues. The last audio test was last month.




Community Member

It's been over a month since I've had a response and this issue is still occuring sporadically. It is disheartening that a year old device is already malfunctioning.

Community Member

The sensor failure/sensor restored error is still happening on the same unit. Is there some sort of resolution for this? It's extremely frustrating that a year old device is having issues.

Nest Protect Status 

Community Member

Is there any sort of resolution for this?? It's been months. I now have another device throwing the same sensor failure.

Community Specialist
Community Specialist

Hello Ltovey,


Chiming in. Apologies for the delayed response here. I’d be happy to help you with your Nest Protect. Let’s check it out.


Please run a Safety Checkup on your Nest Protect and let me know if the device continues to report a sensor failure afterwards. Follow the steps below:


  1. Make sure all of your Nest Protects are installed properly on the ceiling or wall.
  2. Limit other sources of noise in the house, like TVs, laptops, and stereos. These can interfere with the test.
  3. Press the Nest button on a Protect. The blue light should turn on, and it will speak to you.
  4. When it says "Press to test," press the button a second time.

Keep me posted.


Thanks for your help, Jenelyn.


All the best,