Magnets for SmartThings Multipurpose sensors are vayring a lot

I recently discovered that one of my ST multipurpose sensor had erratic open/close events nothing was moving.

ST support changed asked me to replace the batteries, reset, move it out of the window it was mounted on but after a while, the jittering open/close were back.

I had my garage door magnet I didn’t use and by curiosity, I compared it with the faulty sensor one and surprise, it was differently polarized than the garage door one.

I then reported that to ST support who nicely shipped me 2 magnets. But surprise again: one of them is weaker than the second one and look more like the faulty one I have.

I made a video here: (sorry for the noise and the camera reverse left/right… anyway): it is very visible the middle magnet is much more powerful than the faulty (top one) and the 2nd replacement one.

That would be interesting that those of us having sensors issues, try to swap magnets with sensors they have no issue with to see if this improves the situation.

Once we have enough people to confirm this kind of issue, ST could certainly address this as a manufacturing issue. The spec of the magnet to sensor distance is claimed to be 10mm, I can confirm this is impossible with the faulty ones.

Any others?


I have no issue with the magnet, but trying to use it as vibration on my dryer is impossible. It only registers vibration when I slam the door shut. I thought people said these were very sensitive.

You can check the sensors detailed in:

Vibration detection and acceleration detection are different purposes. A vibration could occur within a g-sensor tolerance without being considered as an accelaration

Huh? I thought these were being sold as a way to tell when your laundry was done. It doesn’t work for that. Are you saying a glass break sensor would?

I am not sure about ST promoting this usage, i don’t see it on

Now, if your purpose is to know when the dryer is done, i would rather go for a smartplug and monitor the power consumption. That’s what I did for a pump here Sharing my implementation of grey water pumping

Not a real glass break sensor, which is an acoustic sensor that listens for a specific sound pattern. That won’t have anything to do with telling with the laundry was done.

There was one specific model of vibration sensor for a vision which called itself a “vibration and glass break sensor” and that’s the other one that people were using for laundry monitoring. It’s not an acoustic sensor, you were supposed to have it physically attached to the window where you thought the glass might break.

The SmartThings multisensor does both vibration and acceleration, and I know there are people in the past who have used it for laundry monitoring, but I don’t know anything about sensitivity distinctions between different generations of that device.

I found they still promote this usage on

With its built-in accelerometer, the Multipurpose Sensor can also monitor vibration. Place it on your washing machine to know when the laundry is finished, or attach it to your door to detect someone knocking. You can set it to trigger certain actions as well, like telling the thermostat to adjust when the temperature changes in the room.

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Yeah maybe they slowed down promoting it because it doesn’t work. Here’s another:

I use energy monitoring for my washer, unfortunately I don’t think there’s anything available that would work for my dryer.IMG_20171203_205638