Door sensors for metal doors

I have a fibaro door sensor. I installed it on a metal door. Although, i mounted it on a small wood block, it seems to detect inconsistently.

Most of the time it detects open and close states. However, sometimes it gets stuck at open and doesnt detect close. Is there a brand/model that does not get affected by metal doors or does anyone have any other tricks to improve the situation.

Intestestingly, because the door is metal, i would have expected to get stuck on close state, but it gets stuck on open state.

maybe try 2 sensors at different locations on the metal door. kind of a checks and balance situation. i do this with a lot of sensors so if one trips i can check the status of the other.


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My metal doors have wood frames, so I installed the magnets on the wood frames and the sensor on the metal door. I have not have any problems.

I currently have Z-Wave sensors on these doors but I had ZigBee ones in the past and I didn’t have problems.


All contact sensors that I know of that work with smartthings use magnets, so they all have the same potential issues with metal doors. That said, since you’ve already raised the sensor up onto an onto a wooden block (both parts of the sensor, right?) , you’ve already done the main trick for avoiding this problem.

So next I would consider two possibilities.

  1. is the radio piece on the same side of the door as the hub? sometimes a metal door is just too hard to get signal through. This is one of the few situations that can lead to a door sensor never being marked is closed. The reason is that the signal from the radio gets through when the door is open, but can’t get through when the door is closed, so the hub never receives the closed signal.

However, if that’s the problem, then it should be happening almost every time, not just intermittently.

  1. I think it’s probably more likely that this is just a typical smartthings platform issue that many people report and has nothing to do with the metal door. States just don’t always get updated. :man_shrugging:t2:

(BTW, this problem is amplified for Z wave if you have any zwave energy reporting devices. But that’s a separate discussion.)


If it is, in fact, a problem with the door becoming magnetized, the following post I wrote in 2018 does discuss what commercial buildings do about this issue:

Back to the original problem… If the door is normally kept closed one thing that some offices do is to put a very strong magnet piece on the wall and the sensor piece on the door in such a way that once the door is open about 6 inches, the magnet is strong enough to pull the reed inside the sensor into position. But because the magnet is normally kept away from the metal door, you don’t have the usual problem of the magnet magnetizing the metal of the door itself, eventually causing false readings.
This works best with doors that have a doorstop on the wall as well so the sensor pieces can’t get crushed by the door opening.
In your typical door sensor, the smaller piece is just a magnet in a fancy box. You can replace it with any other magnet, including one that is much stronger or weaker if you want to try to adjust the detection distance.
So that is something which is done in commercial buildings, move the magnet off the metal door all together but is a much stronger magnet so you can cover about a 3" Gap rather than the typical half-inch gap. You’re still keeping it away from the metal door, but you should catch the open event before it’s wide enough to let a person through. Just another option to consider if it works aesthetically for you.

But that would be more commonly used for a door sensor that was reading closed all the time, not one that’s reading open all the time. Still, it’s possibly true that a stronger magnet in a different position might help. But I think it’s more likely one of the two issues I described earlier in this post.

Another alternative if this door has a doorknob with a regular latch/bolt is to put a microswitch inside the wall to detect when the bolt is present. That doesn’t rely on a magnet.

People more commonly use this to determine whether a door was manually locked, but it can work in the kind of situation you describe, depending on the exact details.

There’s a discussion in the following thread starting with the post I will link to about how one community member did this to determine if his door was locked. The thread itself from is from 2015 and is obviously out of date (for example, it refers to shopping at RadioShack) but the basic concept would still work. You need to have something which is physically different when the door is open or closed and you need to have a place to put the microswitch that measures that contact. But it does avoid the magnet issue.

Home made door lock sensor - #7 by johnconstantelo

(Note that the Aeotec recessed door sensor doesn’t solve the problem because it also depends on a magnet.)


Hi @Gagag87

I use the Aeotec multipurpose zigbee sensor (smartthings) on a metal door for years and I have never had any problems, it works perfectly.

The problem you describe seems to be related to the magnet being too far from the sensor. The manual says 5 mm maximum, but if part of the magnetic field closes through the metal of the door then you would have to bring it closer and face the marks of the sensor and magnet as exactly as possible or place a more powerful magnet


Thank you for your reply. I think the problem is also about the status not being updated consistently on the hub. The led indicator on the sensor seems to be spot on when a status changes.

For energy meter devices, i tend to disable energy reporting or set them to report once a day to reduce the traffic. Is this the best approach?

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Yes, that should be fine. :sunglasses:

Zwave was designed for tiny messages sent infrequently. Like “the light switched on.”

As it sounds like you’re aware, Energy monitoring devices that report frequently can flood the network with hundreds of messages, creating the equivalent of traffic jams, making it hard for other devices to get their messages through.

So it’s just a question of message volume. Your setup should avoid that.

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