There are literally thousands of things that can cause false burglary alarms, but if an alarm is professionally installed and operated in a manner consistent with the manufacturers’ instructions it can be an invaluable tool to help keep you and your property safe.  It can also become a nuisance if it isn’t used in the way that it was intended for.  This article’s intent is to help illustrate some of the most common reasons why burglar alarms go off when there isn’t an actual break-in and what you can do to prevent it from happening.


Motion Detectors-

As the name implies a motion detector is designed to detect movement in an area.  Most motion detectors have mechanisms to prevent them from detecting anything other than human bodies but as sophisticated as they have become there are still things that will set them off other than human activity.  Some of the most common causes are animals, balloons, banners, flowers, blinds and curtains.  Even detectors that are supposed to be “pet immune” are subject to false alarms if an animal large enough gets close to the detector.  Inanimate objects such as balloons, blinds and banners can set them off if they are moving in the detectors field of vision.  Flowers or curtains don’t move unless, they are located in areas where the air conditioning or heating system blows on them which can be enough to cause false alarms too.    


Door and Window Contacts –

Door and window contacts are designed to detect when a door or window is opened.  If an alarm occurs, but the door is not opened, it could mean that the contact and magnet are not aligned on the door/window or are not close enough to each other for the circuit to be completed.  This can occur if the contact and magnets are not adjusted properly, but can also occur if the door or window itself is out of adjustment.


French style or double doors are particularly susceptible to false alarms if they are not locked and secured properly.  It is very important to not only lock them, but also be sure to insert the pin into the floor or at the top of the door frame.  Most French doors can be pushed or blown open very easily if all the mechanisms to secure them are not utilized.


Glass break detectors-

Glass breaks come in a variety of styles and types.  The most common style is triggered by the sound of breaking glass.  False alarms from this type of detector can occur from loud or high pitched noises,  especially sounds that mimic the frequencies you might hear if glass if broken. 


Some glass break detectors are affixed to the window pane or frame around the glass and are designed to detect the vibration or shock on the glass if it is hit and/or broken.  Vibration and shock style detectors are susceptible to false alarms from things like birds or balls if they happen to hit the window.  Even if the glass doesn’t break the vibration can sometimes be enough to cause an alarm.   


A very large percentage of alarms are false but we never assume that they are.  Every signal is treated as if it is real until investigated or cleared by someone with a valid passcode.  Most false alarms can be avoided by simply making sure that everything is secured properly before you arm the system.  Every door and window should be locked and closed completely.  Items that can potentially move while the system is armed should be placed in areas that are not covered by motion detector(s).  Even the most informed and cautious alarm users experience false alarms from time to time.  If this happens please remember to notify your central monitoring station that everything is ok in order to avoid the authorities being dispatched and possibly being diverted from a real emergency.


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