To get the most out of Google Home, choose your Help Center: U.S. Help Center, U.K. Help Center, Canada Help Center, Australia Help Center.

Learn about Emergency Shutoff

Emergency Shutoff lets Google Nest Protect tell your Nest thermostat that there’s an emergency in your home. During an Emergency Alarm caused by carbon monoxide (CO), the Nest thermostat can shut off your heating system for safety if it uses fossil fuels (such as gas or oil). During a smoke Emergency Alarm, the thermostat can also shut off fan-based systems to prevent the smoke from spreading further.

What you need for Emergency Shutoff to work

Emergency Shutoff is based on the type of system that you select during thermostat set up. Shutoff for smoke is only available for forced air systems, and won’t be available if you have a different system type, such as hot water. Shutoff for carbon monoxide only works with systems that use gas, oil or other fossil fuels. So if you have an electric system, it won’t be an available option with the Nest app or on the Nest thermostat.

Important: Emergency Shutoff relies on an active account in the Nest app that has both a Nest Protect and Nest Learning Thermostat. It also requires your home to have a working internet service and Wi-Fi connection to both your Nest Protect and Nest Learning Thermostat. The signal is relayed over the internet and can only work if the internet and Wi-Fi in your home are working.

How to access your Nest Protect with the app

When the heating or cooling will turn back on after an emergency

  • After your Nest Protect detects that a smoke emergency has
    ended and your home air is clearing, your Nest Protect will
    communicate to resume your Nest thermostat’s schedule
  • After your Nest Protect detects that a CO emergency has
    ended and your home air is clearing, Nest Protect will
    communicate to your Nest thermostat but you will need
    to manually turn your heating back on again.

What to do if carbon monoxide is detected in your home

Nest Thermostat CO Warning

Important: Since Nest has no way to tell if your furnace was the source of your carbon monoxide Emergency Alarm, you should not rely on this feature. Consult a professional technician to determine the source of CO. Emergency Shutoff is not a substitute for getting out of the house immediately and remaining outside until the alarm has cleared or emergency service has arrived. If carbon monoxide alarms persist, you should investigate the reason by contacting a qualified technician.

Learn about carbon monoxide in your home

Your thermostat will maintain your Safety Temperatures even during a smoke or CO emergency. So if the temperature inside your home drops low enough during an Emergency Alarm, your Nest thermostat will override the Emergency Shutoff and restart heating to help protect against burst pipes. Since Emergency Shutoff and Safety Temperatures work together, make sure that your Safety Temperatures are enabled and set to the temperatures you want.

Note: If your Wi-Fi network goes down before an alarm, your Nest Protect will not be able to communicate an Emergency Shutoff, or that an emergency event has ended, to your Nest thermostat until your home Wi-Fi network is working again. Your Nest Protects will still try to communicate with each other. This communication does not use your home Wi-Fi network. Visit Weave for more info.

Enable or disable Emergency Shutoff

By default, Emergency Shutoff for CO is on and Emergency Shutoff for smoke is off. You can change Emergency Shutoff with the Nest app or on the Nest thermostat.

With the Nest app

  1. Open the Nest app.
  2. Tap your Nest Protect.
  3. Tap Settings Nest settings icon.
  4. Tap Works with Protect.
  5. Enable or disable Emergency Shutoff for both smoke and for CO alarms.

On the Nest Thermostat

  1. Go to Settings Nest settings icon.
  2. Select Nest Protect.
  3. Choose CO Shutoff or Smoke Shutoff.
  4. Select Yes to enable this feature or No to turn it off.
  5. Choose Continue.
  6. Choose Done.

Note: You must have a Nest Protect added to your account
in the app in order to have this option in the settings menu.

Nest Protect Shutoff

Emergency Shutoff will be disabled when your home is set to Away either manually or automatically. This helps prevent damage from extreme temperatures if there’s no one home to silence a false alarm.

Differences in Emergency Shutoff for smoke or CO

The table below outlines the similarities and differences between CO and smoke Emergency Shutoff: how it works and what it can do in different situations.
Emergency type Carbon monoxide emergency Smoke emergency
System types it works with Fossil-fuel systems (oil, natural gas, etc.) Forced air systems
Benefit Cuts off a common source of CO Helps prevent smoke from spreading
On or off by default On Off
Emergency Shutoff can be manually overridden Yes Yes
System automatically turns back on after alarm ends No Yes
Respects Safety Temperatures Yes Yes

Was this helpful?

How can we improve it?
Clear search
Close search
Google apps
Main menu