Normal operation · Google Nest Protect · smoke
Google Nest Protect: Brief green glow when you turn the lights off
Nightly Promise: Protect has checked its sensors, batteries and Wi-Fi and everything is working.
- What you see
- One green flash
- What you hear
- Silent
If it is sounding a full alarm instead: the maker’s emergency instruction
Smoke alarm
Google (Nest Protect): at an emergency smoke level Protect sounds a continuous alarm and says “Emergency”. Get out of the house immediately: follow your evacuation plan, alert small children and anyone who needs help, feel doors with the back of your hand before opening them, close doors behind you, meet at your meeting place, count heads and call the fire department; do not re-enter unless a fire official says it is safe.
From What to do if Nest Protect detects smoke in your home — Google Nest Help and Nest Protect lights and sounds — Google Nest Help.
Carbon monoxide alarm
Google (Nest Protect): when CO reaches emergency level Protect says “Emergency. There’s carbon monoxide in the (room). Move to fresh air.” Press the centre button to silence or reset Protect, call your fire department or 911, move everyone to fresh air, and do not re-enter until the emergency services tell you to.
What Google Nest Protect says to do about this signal
- Nothing to do. If it glows yellow instead, press the button to hear what it needs. If there is no glow at all, the room may not be dark enough.
From Nest Protect lights and sounds — Google Nest Help. If your alarm’s pattern is not exactly this, check the manual for your model: Google Nest Protect models do not all use the same signals.
Other Google Nest Protect signals
Normal operation on other brands
The same state sounds and looks different on each make — which is why a chirp pattern cannot be read without the brand.
Sources
Every line on this page comes from Google Nest Protect’s own documents, read on the date shown. Nothing is taken from third-party code sites or other makes.
- Google: Nest Protect lights and sounds — Google Nest Help — Nest Protect (1st and 2nd gen, battery and wired). support.google.com Checked 2026-09-29.
- Google: What to do if Nest Protect detects smoke in your home — Google Nest Help — Nest Protect. support.google.com Checked 2026-09-29.