Article Summary:
This table tells you more about what the Nest Protect light ring means and what you can expect to see.


What you will see every day

Most of the time Nest Protect’s light ring will be off. When it lights up, it means that Nest Protect has something to tell you.

Light ring on Nest Protect

What it means

  • During setup, Nest Protect will glow blue when it’s awake and ready to be configured.
  • Before and after a manual test, Nest Protect will glow blue.

How and when should I test my Nest Protect?

What is Nightly Promise?

  • A green light after a Heads-Up or Emergency Alarm means that the conditions are returning to normal. Nest Protect will tell you that smoke or carbon monoxide are now clearing.

What is Pathlight?

No light

Most of the time, Nest Protect's light ring will be off.

Blue light

The blue light shows that Nest Protect is active and ready to be connected or tested.

Green light

  • Nest Protect will pulse green during and after setup to confirm that it’s connected to the Internet and setup is complete.
  • Nest Protect will pulse green at night when you turn off your lights to let you know that it tested the batteries and sensors and everything is working correctly.

White light

Pathlight is soft white light which comes on as you pass under Nest Protect in the dark.


What we hope you won't see

Nest Protect uses yellow to give you an early warning and red for emergency situations.

Light ring on Nest Protect

What it means

  • If Nest Protect senses low levels of smoke or carbon monoxide (CO), it will give you a Heads-Up and let you know where and what type of danger it is.
  • If a Heads-Up alert has been silenced by pressing the Nest button, Nest Protect glows yellow. Nest Protect remains quiet for a few minutes while continuing to monitor your home.
  • If Nest Protect detects an issue such as low batteries, sensor problems, or that it has expired, it will pulse yellow when you turn off your lights at night.
  • If Nest Protect fails a manual test, it will glow yellow to indicate that there is an issue that needs to be addressed. Nest Protect will let you know the problem.

What’s the difference between a Heads-Up and an Emergency Alarm?
What is Nightly Promise?
What types of alarms can I silence?

What’s the difference between Heads-Up and Emergency Alarms?
What types of alarms can I silence?
What should I do if carbon monoxide is detected in my house?
What should I do if Nest Protect detects smoke in my house?

Yellow light

The yellow light indicates an advance warning.

Red light

  • The red light means that Nest Protect has detected dangerous levels of smoke or carbon monoxide. A red light is accompanied by a loud alarm sound and a voice alert telling you what and where the danger is.
  • If a CO Emergency Alarm has been silenced by pressing the Nest button, Nest Protect will glow red. Nest Protect will remain quiet for a few minutes while continuing to monitor your home.

In the case of Nest Protect (Wired 120V)

Light ring on Nest Protect

What it means

Small green light

For Nest Protect (Wired 120V), a small green LED glows to confirm that Nest Protect is connected to power. Regulations require that all wired smoke alarms have this light.