On the covered Google Nest Protect alarm, a yellow ring, chirp every 60 seconds (CO sensor) means carbon monoxide sensor failure. Google says Protect tested its CO sensor and detected a problem. First, push the Nest button to hear the message and confirm which sensor failed.
Try in this order
0 of 8 completedWhat to do first
ReversiblePush the Nest button to hear the message and confirm which sensor failed.
Correct only the documented fault domain
ReversibleGoogle's instruction is to replace the Protect now, with no cleaning step listed for a carbon monoxide sensor failure. In the US you can send the old Protect back to Google for recycling.
Replace the alarm, not the batteries
ReversibleA failed carbon monoxide sensor cannot be repaired; Google's guidance is to replace the Nest Protect.
Push the Nest button to hear the message
ReversiblePress the Nest Protect's button once. The spoken message confirms which sensor has failed. A yellow ring with a chirp every sixty seconds points to the carbon monoxide sensor, which Google says it tested and found to have a problem.
Do not rely on the alarm for carbon monoxide
ReversibleA Protect with a failed carbon monoxide sensor cannot warn you of carbon monoxide. Until it is replaced, fit a working carbon monoxide alarm nearby, and treat symptoms such as headache and nausea indoors as a reason to go outside.
Replace the Protect now
ReversibleGoogle's instruction is to replace the Protect, with no cleaning step for a carbon monoxide sensor failure. Check the warranty on the unit and contact Google support, since a unit that fails early may be replaced.
Recycle the old unit properly
ReversibleIn the US, Google lets you send the old Protect back for recycling. Do not put an alarm in household waste, since it contains a battery and a sensor.
Test the new unit
ReversibleAfter fitting the new Protect, run a manual test from the Nest app and check that the ring is green. Test it monthly after that and record the date of fitting.
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Exact questions
Common questions about “Google Nest Protect alarm showing a yellow ring, chirp every 60 seconds”
What does a yellow ring, chirp every 60 seconds (CO sensor) mean on a Google Nest Protect alarm?+
Carbon monoxide sensor failure. Google says Protect tested its CO sensor and detected a problem.
Is my home safe if the Nest Protect CO sensor has failed?+
That alarm can no longer detect carbon monoxide. Replace it, and use another working CO alarm until you have.
How do I test a Nest Protect's carbon monoxide sensor?+
The Nest app's Safety Checkup and the alarm's monthly test check the sensor; a failed one shows the yellow ring and the chirp instead.
Does the smoke part of a Nest Protect still work if the CO sensor failed?+
The alarm is treated as failed as a whole and should be replaced, because it can no longer do the carbon monoxide job it is installed for.
What does a yellow ring with a chirp mean on a Nest Protect?+
A sensor failure; with the carbon monoxide message it means that sensor has failed.
Can I clean the sensor?+
Is the smoke alarm still working?+
The message tells you which sensor failed; listen to it.
What should I do now?+
Replace the Protect and use another carbon monoxide alarm until then.