More false alarms on my original ST motion sensor

I have had my ST system for over two years now. And in that time I have received multiple false alarms from the same motion sensor. I would say it happens 2-3 times a year. Now some of them I actually do think are something in that room falling over. But last night I see nothing in the room that would indicate that something happened. The only thing i have thought might be causing some of these alarms are:

  • During the day, sunlight fluctuations. I now always keep my curtains closed.
  • I do have a kinect for an xbox, which i have seen projects an infrared field into the room. So I thought maybe that turning on or off could trigger it randomly because of a mixup.
  • Third and most likely option i have a slightly faulty device.

I assume it is 3rd. It works the majority of the time with only a few really in a year, but that is enough of an annoyance (waking up at 3AM or having to drive home to make sure all is ok), that I am thinking I need to replace the device. Unless someone has a suggestion.


I just got a blizzard of false motion logs from multiple ST motions (like 5-6). The record is inconsistent: The only motion reported in smartapp is one SmartSense battery motion. Looking at the live log though, shows motions in a couple Aeon multisensors gen2 and the SmartSense, around the same time. Also the live log shows MANY (like at least 5 sequential) Zwave searches started around the same time.

Seperate cameras show no motion in the records so I’m not concerned about actual motion. It’s just ironic that yesterday I posted that I had no significant operational issues. I don’t use SHM or ST-sirens so there are no false alarm consequences.

Also all these false motion logs DID NOT trigger any routines since the presense/arrival sensors did not report any change (which was correct status).

Since these motions are all in different areas of the house, and most are not possible to be exposed to drafts or sunlight, then I am assuming that ST is doing some kind of remote diagnostic or maintenance, or it’s a cloud-related malfunction.


Another thing to consider - As we are moving into winter, the A/C vents may be turning ON/OFF and there may be sudden bursts of warm air in the room. Try to check if the motion sensor happens to be in view of a A/C vent which can trigger these false motion every time the vent comes on. I had a motion sensor trigger false alarms and when I moved it to a different location, it was all good. It was initially in line with the A/C vent.

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This… exactly this, the moment I set the thermostat to cool AND heat (instead of just cool) I’ve been see false triggers.

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This would be in line with most of my false triggers have been in the winter season. I haven’t had a false trigger all year until last month and I have had two. Not really sure though how to protect against this because my motion sensors are looking over my whole basement and there really isn’t any line of sight that would not have a vent in its width.

I went ahead and bought a new generation of motion sensor, any chance these would be avoiding this problem.

One thing you can do is place the motion sensor lower on the wall. You can consider placing it at the same height as your switches. You can also redirect the airflow from your vents by adjusting the blades to point more downwards instead of a 45 degree angle.

I had exactly the same situation in my Kitchen where the best possible location was right under the vent. but after the episode with my game room sensor, I placed the kitchen motion sensor right next to the switch - fortunately it was located well to cover all entry points to the kitchen.

I have 5 second generation motion sensors. I bought them new with my v2 hub 1 month ago!

All was fine with my smart home monitoring, then 4 days ago my conservatory motion sensor reported a intrusion status. It just triggered the once!
Today, my motion sensor in the hallway gave a false trigger twice within 6 minutes!

This lead me to wonder if it was down to glitches in the hub, if the firmware in the sensors are updated by ST remotely, or if the False alerts are generic to the PIR motion sensors.

It would be nice to see an option to enable cross zoning, so that 2 different triggered sensors are required to positevely identify an intrusion.

I have not read much mentioned about these false triggers, so now i am wondering if i have interference or a fault.

I am not to sure if the firmware updates, in the past have affected the sensors to operate reliably!

My sensors currently show 88% battery and the furthest sensor is 4 metres away!

There is one created by @Mike_Maxwell. You should be able to find it if you search the forum.

@NHENRY, here’s the link page…

This is great! I am looking forward to trying this out.

Thanks guys!

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I was wondering if there is anyway to use a door sensor and motion sensor combined in false reduction mode. In the motion manager software I can only see a motion device as a input?