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Citizen 's profile

Thursday, November 30th, 2023 9:20 PM

Sensor False Alarms

We have had two situations where the siren was activated and there were no intruders, no one was caught on external cameras, no door or window open, nothing that should have trigger the siren. Yet twice we were woken up in the dead of night with the siren blaring. The first time we called the police and they checked the basement where the system said the alarm was triggered. Nothing. Door, storm door and windows still locked, no sign of tampering, no one on camera. Last night the siren was triggered again and after stalking through my home with my weapon, the door that triggered the siren was closed, the storm door still locked, the entry door still locked, latched, secure, no sign of tampering. Nothing on cameras. There was no reason for the siren to be triggered. What is happening? Thanks for any clues I can get.

This post was created from this comment on different post

Community Admin


2.9K Messages

7 months ago

Hello @Citizen , 

It sounds like something is triggering false alarms on your system. You mention two different situations where this happened - do you know if these alarms were triggered by the same sensor or different sensors?

The Entry Sensor on your door that triggered this alarm last night, does it happen to be placed on a metal surface? We do not recommend putting either part of the Entry Sensor on metal, as it can cause the sensor to demagnetize and make the system read the incorrect open/closed state. If this sensor is on a metal surface, it can help to place a buffer between the door and the sensor; you can use anything like a piece or cardboard or an additional layer of adhesive. 

Entry Sensors can also cause false alarms if the sensor and magnet are further than 2 inches apart. As the weather is beginning to get cooler - which can cause houses to shrink - I would check this Entry Sensor to make sure both pieces are still close together.

2 Messages

@emily_s​ Hi! Thank you for your reply. The first was triggered by a motion sensor in our basement. Cameras did not show any animal or large flying insect.
The second was an entry door sensor upstairs. Again nothing on camera. everything secure.
Why yes, the door is metal but the frame is wood. And yes, the motion sensor that triggered is on top of a upright freezer.
I will fix this and put extra layer of adhesive on both. Thank you! I'll let you know if it works.


Community Admin


2.9K Messages

@Citizen Thank you for these additional details! Regarding that false alarm triggered by your Motion Sensor, our Motion Sensors use passive infrared to detect sources of heat moving around. So you are absolutely correct that if there is a blast of hot/cold air near the Motion Sensor and it detects a sudden temperature change, it can trigger a false alarm. Is there anything near your Motion Sensor that generates hot or cold air - like heating/AC vents, windows, or a boiler? If so, I would recommend moving the sensor away from that object. 

Light can also trigger the Motion Sensor - like sunlight directly shining on it or a sudden burst of lighting. However, since this alarm happened around 3 am, sunlight doesn't seem to be a likely cause. 

It could also be that a small insect was able to get close to your sensor and crawl about it, causing it to pick up on that motion.

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