Contact Sensor sensitivity and constant false alarms


#1

I have a contact sensor on my front door. Every single morning between 7:00 and 8:00am that sensor triggers an intrusion and sets off the alarm (I turned off the siren after 3 days of this). I’ve been sitting in the adjacent room when it’s triggered and can confirm that nobody opens the door, and nothing hits the door causing it to jolt or anything…it just triggers for seemingly no reason. The only thing I think of that could possibly cause this is that my house faces east, so the rising sun beating against my door cause the wood to swell by a millimeter (probably not even a millimeter)?

I’ve tried to adjust the position of the sensor, and will try swapping it with another sensor this evening, but I’m wondering if anyone else has had this problem? I’m very curious about what could be causing this so any ideas would be appreciated.


#2

What’s the brand and model of the contact sensor? Sometimes it is something as simple as a school bus that goes by or warming temperatures.

First, though, make sure that it is in fact the contact sensor that’s causing the issue.

You’ve probably already done this, but check the individual event logs for the sensor to make sure that it was in fact triggered.

In particular, check to make sure that you don’t have a once a day battery check or device wellness check that might be reporting a poll response from that sensor as an event.

After that, check the notifications or the full logs to make sure that it is that sensor that is triggering the intrusion.

If it was me, I think the first thing I would do besides checking the logs is just take the battery out of that sensor. Then if you still get an intrusion alert the next day, you know it’s not that sensor. If you don’t get an intrusion the next day, it probably isn’t that sensor, and then you can start tracking that down.


(Ben W) #3

I had a similar situation with a window. On hot days (above 80ish) it would always trigger.

I found that that one window had some play in it, I could push it up a bit while locked, which caused the sensor to open.

To better align the sensor I placed a couple of the 3M commands strips under the magnet. Then checked the window play to make sure it still reported closed. I did this yesterday, fingers crossed my issue goes away.

My suggestion is check for any play in the door, even slight movement can cause it to report open. If there is try adjusting the magnet, many doors there is a dip or a lip that does not align up 100%. You can also try getting a bigger magnet for the door.


#4

The alert I get is that it is that contact sensor that is tripped, and the logs show each morning that it was that sensor that triggers the alarm. In fact checking the logs show that the sensor records the door opening and closing repeatedly over and over again all morning starting at the time of the alarm trigger and going on and on until about noon each day. Here is a bit of the log from this morning https://goo.gl/photos/FUZCNv3MCTeusmNMA. You can see how it was triggering open/closed over and over again but at 11:10 is slowed down and didn’t register another event until 11:24 (also note the 11:24 was a temperature check-in). I was sitting in my living room and I can confirm that that door had not opened once all morning, let alone at 11:10.

It is the contact sensor that came with the SmartThings starter kit so I assume that’s a Samsung brand?


#5

I’m using the sticky tape, not the magnet, but this sounds like it’s the same problem. My first thoughts were that it is the wood in the door swelling/shrinking in the humidity and heat (even though today is low humidity and about 70 degrees). What I may try is moving the sensor further down the door where there would be less movement or give. Closer to the hinge maybe?


(Ben W) #6

I think there is a pressure change, either inside or outside that is causing the door to shift. The test should be easy, just push or pull door (while closed) and see if sensor changes.

I used a couple layers of the 3m tape on the magnet to better align with the sensor at the furthest movement.

You are right, the hinge side should have less play, but will need more movement to trigger open.


#7

I didn’t think about pressure, but that’s an interesting idea. I did just play with it a bit and maybe it’s too late in the day today because it didn’t change as I pushed on it. I’ll see to it in the morning when the problem occurs. Thanks for the input!