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How to troubleshoot Nest Secure false alarms

There are a few things that can cause Google Nest Secure to sound an alarm when there isn’t an intruder. Not disarming before the timer finishes is a common cause, but other things like heating appliances, fans and pets can also trigger the alarm. Simply checking your installation or changing the settings can help prevent many false alarms.

Nest Secure has advanced features like Reduced Sensitivity and Quiet Open to help prevent false alarms from happening. We designed Nest Secure to make it easy to use, but there are several things you should keep in mind to help prevent false alarms.

Quiet Open doesn’t disarm all Nest Detects

Quiet Open only temporarily disarms the Google Nest Detect that had its button pressed. So if you want to open another door or window, you’ll need to press the button on the Detect installed there. Closing the door or window will also rearm the Detect. So if you want to briefly step outside to pick up the newspaper off the porch don’t close the door.

You can make disarming Nest Secure easier

Disarming with Google Nest Tag  or the Nest app is generally faster and easier that entering a passcode, but you can also easily change the amount of time you have to arm or disarm Nest Secure so you don’t have to rush when you get home or you’re leaving.

You can also enable Remind Me notifications, so you’ll get an app message that you can tap to disarm Nest Secure before you walk in the door. Remind Me notifications are especially useful if other people can arm or disarm Nest Secure. Sometimes one person who has shared access to your Nest home will arm Nest Secure and another person will enter the house without realizing it’s armed. For instance, they may come in through the back door and not hear Google Nest Guard say they need to disarm.

How to troubleshoot false alarms

Things outside your home generally won’t cause false alarms

Before you start troubleshooting, keep in mind that Nest Detect and Nest Guard can’t detect motion through a window, door or wall, so swaying branches, passing cars, people walking by, or other movement outside your home won’t trigger the alarm.

Determining what caused a false alarm

If you suspect something specific that’s triggering a false alarm, you can run a security test to help confirm that’s what caused the problem. For instance, if a certain Nest Detect is repeatedly sounding false alarms, and it’s installed near a heating vent, turn on your heating. Check to make sure warm air is coming through the vent. Then set Nest Secure to Away and Guarding Away and guarding. If the alarm sounds and the app notifies you that Detect caused it, try reinstalling that Detect in a different location in the room.

If you don’t suspect a particular cause, a couple of simple questions can narrow down the likely source if you’re not sure:

Do the false alarms happen on a regular schedule or at random times?

  • If it’s on a regular schedule, check any automated appliances, electronics, heaters and similar things that might be programmed to turn on and off at specific times.
  • If the false alarm times are random, check your pets (if you have any). Also look at Security History to see when other people who share access have left or come back home.

Is one Detect sounding false alarms, or are different Detects?

  • If it’s one Detect, the cause is likely something that stays put in that room, like blinds or curtains that are close to where that Detect is installed.
  • If different Detects are being triggered, the cause may be something or someone moving through your home, like a pet or your housesitter.

Things that can cause false alarms

The following things can be causes of false alarms:

  • Pets that walk, climb or fly above 3 feet (1 m)
  • More than one dog under 40 pounds (18kg)
  • Pets heavier than 40 pounds (18 kg)
  • Pets going up or down stairs
  • Heat sources like electric heaters, heat vents and fireplaces
  • Cold sources like drafty windows, air conditioners and AC vents
  • Curtains near windows that may move while Nest Secure is armed
  • Direct sun exposure: the front of Nest Guard and Nest Detect should not be placed in direct sunlight
  • Party balloons left unattended: they may drift into Nest Detect’s or Guard’s sensor range
  • Insects that may come very close to the sensor
  • Vibration or movement caused by pets bumping Nest Guard when it’s set to Away and Guarding Away and guarding
  • Wireless access points within 6 feet (2 m) of Detect.

What to do when pets cause false alarms

We made Nest Secure dog friendly, but sometimes the animals we love can set off the alarm. If you have a pet and you’ve had one or more false alarms while you’re away from home, try changing these settings.



Dogs can set off the alarm when Nest Secure is set to Away and Guarding Away and guarding and is looking out for motion.

Turn on Reduced Sensitivity

When Reduced Sensitivity is on, Nest Secure ignores movement of small and medium size dogs (under 40 pounds) as long as they stay on the floor and don’t jump on furniture.

Large pets, and pets that climb or fly, can set off the alarm if Nest Secure is set to Away and Guarding Away and guarding, even when Reduced Sensitivity is on.

If Reduced Sensitivity doesn’t help with pet related false alarms, there are two additional settings you can try:

Turn off Motion detection for Detects

When you turn off motion detection, your Detects will only look for doors and windows opening or closing. If you have a large dog, llama, miniature horse, parrot or similar pet, you can disable motion detection for each of the Detects in your home.

Turn off motion detection for Guard

This is a separate setting found in Guard settings, and may help if cats or other pets that climb trip the sensor on Nest Guard.

How to change Nest Secure system settings >

Note: Reduced Sensitivity is meant for a dog under 40 pounds that stays on the floor and doesn’t jump or climb on furniture. It won’t ignore animals that climb or jump because motion that occurs higher above the floor can be caused by a human intruder. Similarly, a large pet’s movement and heat signature can look like a human’s to Nest Secure.

Cats present a unique set of issues for Nest Secure. They typically won’t trigger an alarm on Detects. However, they can be attracted to the lights and sounds coming from Nest Guard and can trip its motion sensor.

Turn off motion sensing

Try turning off motion sensing for Away and Guarding Away and guarding. This setting applies to all Detects in your home as well as Guard.

A pet going up or down a staircase may trigger a nearby Detect to sound the alarm.

A dog (regardless of size) or other pet will usually be detected when it goes up or down the stairs even if Reduced Sensitivity is on.

Turn off motion sensing

If the Detect near the staircase is installed on a door, you can turn off motion sensing for that one Detect while keeping motion sensing on for the rest of your home.

If the Detect is installed on a wall, you have two options. You can turn off motion sensing for Away and Guarding , which turns off motion sensing throughout your home. Or you can keep motion sensing on and move the Detect to a different location in your home.

What to do when heat, appliances or other things in your home cause false alarms

Everyone’s home is different, and things that can happen while you’re gone or even at home that cause a false alarm. While it’s pretty easy to tell if you, a family member, or one of your pets set off the alarm by accident, false alarms caused by appliances and other things in your home can be difficult to solve. Here are some things to look out for that may cause an unexpected false alarm.



The motion sensors in Nest Detect and Nest Guard can be triggered by heat sources including:

  • Furnace vents
  • Radiant heaters (electric/hot water/steam)
  • Portable electric space heaters
  • Fireplaces
  • Gas heaters installed in the wall or floor
  • High power light bulbs, like halogen bulbs
  • Candles

Make sure that all Nest Detects are at least 3 feet (1m) away from any heat sources (including open flames), and that any heat source is not in the sensor’s field of view.

Nest Guard and Nest Detect may need to be even farther away from larger heat sources such as fireplaces.

Refer to your User Guide for details about the sensor ranges.

Appliances that move, like fan blades and robotic vacuums, can trigger the motion sensors in Nest Detect and Nest Guard.

Appliances that move should be placed out of Nest Detect’s and Nest Guard’s sensor range. Refer to your User Guide for details about the sensor ranges.

If that’s not possible, you may need to turn on Reduced Sensitivity or turn off motion sensing on any Detects or your Guard that are near things that will move when you’re not at home.

In some cases, extended exposure to direct sunlight can affect Nest Guard’s and Detect’s motion detection.

Direct sunlight is usually restricted to the floor and areas that are relatively low on the walls, so this isn’t a common issue.

If the Nest Detect that’s causing false alarms is on a wall, reinstall it in a location where the sun isn’t shining directly on it.

Detects installed on windows aren’t set to detect motion, so exposure to sunlight isn’t an issue.

You should also place Nest Guard in an area where it won’t be exposed to direct sunlight.

Blinds and curtains can be moved by air coming through vents in your home or a breeze from an open window. This can trigger the motion sensors in Nest Detect and Nest Guard.

Keep in mind that curtains moving won’t affect Detects mounted on windows since they aren’t set to detect motion.

Make sure that Nest Detects that are installed on the wall and Nest Guard are located at least 1 foot (30 cm) away from the blinds or curtains.

If the Detect is installed on a door, you also have the option to turn off motion sensing for that Detect.

Large flying insects like moths can trigger Nest Secure’s motion sensors.

If you like to leave your windows open, put screens on them to keep moths and other insects out.

Helium balloons can move in the air currents from vents, or drift across the house and trigger Nest Secure motion sensors.

Balloons must be placed out of the field of view of Nest Detect or Nest Guard.

If you’re hosting a party with balloons, you may want to arm only in Home and Guarding mode until there aren't any balloons left in your home.



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