Almost 70 false motion alarms this year!

I have 11 ST motion sensors and they are driving me nuts!
Is there a smart app that will allow me to trip the home monitor only when 2 sensors have been tripped within a predetermined time frame? I’d like it connected to the built in home monitor so I can be reminded of an intrusion and be able to dismiss the alert.
I understand that many of these false alarms might be caused by weak batteries, but I’ve had this problem since day one. I’m not interested in reducing the number of false alarms, I want to eliminate it entirely. I also want to get the most life out of the batteries and not have to replace them when they read 78% (I understand that the reading is within a range).
I’d like to be able to connect my sirens to my smart home monitor, but with 70 false alarms within 3 months, and many being at night, the alarm would likely disturb the neighbors.

I’m sure that’s very frustrating! :disappointed_relieved: there are two different ways to approach this.

First, there’s the zone manager app which was designed for exactly this issue and just combines multiple motion sensors into one reporting unit. It’s very popular and works well.

If you want more complex logic, core can do pretty much anything you want, including changing delay periods and all that:

I’m sure there are other ways to do it as well, but both of those will definitely work depending on your needs.

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Do you know what’s causing this? I have several ST motion sensors, and the only time these were going crazy was soon after ST introduced the over the air firmware update feature.

I will give them a shot starting with the first one and give an update after installed.
Hopefully this resolves my issue.

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I don’t know exactly what is causing it. I have security cameras right next to some of the motion sensors and I don’t notice anything on the cameras.
I’ve been told that rapid changes in IR can cause this, but I have a geothermal heating/cooling system (low airflow and temp). Also many of the false alarms occur at night.
Another possibility is insects, but again I don’t notice insects in the house.
And lastly I’m told that a weak battery can cause false alarms, but I’ve had this issue when all batteries were new.

I have yet to move into the house so I can observe the conditions when a false alarm is triggered (hearing a fly in the area, heat just kicked on, or a cloud just passed by, etc.)

I’ve run batteries down to 11% without issues, that is until they stop reporting altogether, but I can’t imagine how a low battery would trigger a motion event. That sounds too odd to me.

When you finally move in you should let us know what you find out the cause of the false alarms.

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Those are the 3 “excuses” I’ve been given.
Since the house is currently vacant, many people have attempted to break in (without damaging property), for this reason I’d like to resolve this issue before moving in.

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I recently had this ‘issue’. Battery was at 68% according to the app. I wondered if that was accurate and replaced the battery. Problem went away!

I think the app reports inaccurate battery percentage. Worth trying a swap just to eliminate the doubt about remaining battery power :slight_smile:

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I agree with the app not reporting proper battery percentage. I’ve seen sensors magically recharge themselves.
However I don’t believe that replacing the batteries will resolve my issue, I believe it will reduce the number of false alarms but not all.

I’ve installed Zone Motion Manager and it seems to do exactly what I wanted it to do.
Only time will tell but I believe that I can now rely on my SHM!
Thanks for the help!


I have a false motion notification about 3-4 times a year, but my traditional security system had 0 and cost $5 per sensor lol

Who monitored your traditional security system? And could those sensors be used as home automation as well? Where they wireless?

If it was monitored by you, sensors were wireless and could be used as home automation, then I’d be impressed. From what I’ve been told, these 3 cases are a recipe for false alarms.

Some security companies require 2 motion sensors to trip before notifying you, some sensors have adjustable sensitivity but for $5 I doubt yours had that capability, sensors used as home automation are built to be triggered easily in order to quickly trigger commands, and lastly wireless sensors use IR to detect motion can be easily tripped by a change in heat, light, or insects.

This info is all from what I’ve been told, I cant back any of this up with any “facts”.

It’s worth a shot to look at zigbee interference and mesh. Maybe move your hub to another location and buy more zigbee repeaters. I went crazy with zigbee repeaters late last year and begining of this year and all my ST motion sensors are solid now (knock on wood). I only get false alarm when the battery is low. I have quite a few ST motion sensors maybe around 10. I also mounted most of them on the ceiling to prevent motions from coming from doors/windows during sunny days.

It is a very old wired system that I am still using so I have two sensors on each door. (One for SmartThings + wired door sensor)

It makes a click noise and has a red led when it detects motion, I am still paying the $25 per month to monitor it

I currently have 3 Zigbee repeaters, I’ve only once had a false alarm from a ST multi sensor. I don’t believe interference is causing my problems, I will tinker around with the hub location after moving in, but for now it is staying hidden where its at (in case of a break in).

If I were you (assuming you get to keep the wired system), I’d cancel your $25/month monitoring fee and have the old system trigger a ST sensor. Doing this will pay for itself within 2 months.
After all what are they doing to monitor your home that you cant do? If anything they just delay the response time of the authorities since they need to contact you first. You could even setup a SMS message to be sent to someone you trust in the event of a break in.

I still depend on it for cellular monitoring and reliability.


I was in the same mindset as well. Only motion sensors problem but no door/window sensors fault. It’s above my knowledge grade on this one for sure.
One other thing to look for is WIFI channel. Not much you can do with ST hub zigbee channel but you could change your WiFi router channel or move away from your neighbor WiFi. Have you tried a mesh heal? Also contact support to check your mesh. They have the ability to map out the mesh.

This was driving me nuts as well and I couldn’t figure out what was causing it, until I watched the room in question using a night vision IP cam. I realized that things like my ecobee thermostat, my motion sensors, and my kids baby camera, were all sending out pulsing non-visible light (it wasn’t visible to the naked eye, the camera didn’t pick it up when in daytime model, but it looked light a flashing white light when in night-vision mode). I suspect the flashing light on one device is causing the alarm on the other device, and these alarms are triggered when the devices move from daytime to nighttime mode (this is all a guess, but my false alarms seem to be strongly correlated to that hypothesis)

I had a lot of false alarms even when left in a closed box. I’ve been told the explanation is that when the device uses the zigbee radio to send a pulse back to the hub, it drains the the battery voltage to a point that the sensor misfires and therefore a false motion occurs. Seeing as the recent healthcheck updates have increased the frequency of the pulses from once every two hours to every 5 minutes you can see this happening a lot more often than in the past.
Best practice is to take the battery out and measure using a voltmeter rather than rely on the % of the devicetype.

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