In-wall magnets to make sensors stick

I just bought my first Xiaomi sensors (vibration, but I suspect the temp/hygro sensors are identical case-wise) and I am wondering if fixing them to a magnet set in plaster in my wall would make sense (they come with 3M sticky pads, I would probably have to change these pads each time i change batteries, or change position). A magnet in the wall could probably be hidden behind white paint, while a 2cm sticky circle will leave more ugly residue on the wall. The sensors are magnetic, they stick to the magnet of the Hue motion sensor just as the Hue device does.

Stupid idea? Has anybody tried that? What kind of magnet does not show rust spots after a few years in the wall? I once had a nail or something that “came through” no matter how often you painted over it.

Are you sure that you need to remove the device from the wall to change batteries? E.g. I can change the battery for my Xiaomi Door/Window sensor without removing it from the wall and the same goes for all my other battery powered devices. If you need to remove the device from the wall, it’s a stupid design :frowning:

I just use blue tack. The door sensor as well as the temp sensor work perfectly with just a little blue tack.

You don’t need to remove them to change the battery. Just twist them. The glue will hold well enough to let the back stick to the wall while you twist the rest off.


Thanks everybody, I think I will try bluetack first

I don’t think removing the sensor from the wall will work for my walls, even if the back of the battery door can stay on the wall in principle. I think the paint on my wall will come loose first (it does with posters or other things stuck to the walls. Might work on smooth surfaces, though.

Blutack will leave greasy stains on the wall after a few months.

There are “command strips” which are like 2 pieces of male velcro (ie both are hooks) they have a glue strip behind them. You mate them, remove the backing strip one side to stick to the thing your are mounting then you remove the other, position on the wall - voila !
Take off, put on, take off, put on …
When you need to decorate you will loose the wall strip side (so buy spares) you hold the top of the strip in place, pull down on the glue tab and it stretches the glue losing binding to the wall, comes away clean with no blue tack marks.

I’ll post a link if needed, but they ‘may’ call it something else in your country (probably not cos of globalised markets and multi-language packaging)


Wow that’s a long url

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Depending on the sensor weight and position in the wall you might be able to use a strong neodymium magnet stuck to a drywall corner piece (most corners sticking out are reenforced with a metal angle strip) or find a nail/screw to affix it to. Also metal door frames (such as exterior doors on apartments) often have

I used this trick in a rental to mount a small IR LED floodlight on the corner of a wall lighting a hallway without drilling extra holes.

Using a magnet to find drywall nail/screw is also a handy way to find studs if you don’t have a fancy tool.

I also did this to stick Aqara vibration sensors on the back of the rental washer and drier where I live…so far so good and no damage or goo to remove when I move out.