All our entry doors were still locked, but our side door reported being open and after the 45sec entry delay, the alarm sounded. Is it common to have an entry sensor report a false alarm? or do I perhaps have a defective sensor? Alarm has been installed for about 2 years and never had a false report before. We do have a steel entry door with a magnetic curtain rod attached, but it’s several inches from the sensor and hasn’t ever been a problem before.
Thanks!
Happy to help! Given the simplicity, typically no, a sensor will not just open without a physical cause of some sort. The reed switch would need to be released by movement of the magnetic field. It is always best to explore environmental causes first.
Looking at the history, the telling details are that the door was opened and closed quickly, then appears to have opened again very shortly after before another open would register in history, because the next signal I see from it is another closed status a few minutes later after the alarm.
Was anyone home at the time? I noticed the system was armed stay and a motion detector was actually activated about 20 seconds before the door reported opening/closing the first time.
As a shot in the dark, do you have a dog who might’ve heard something and jumped against the door?
If the door has some wiggle room forward and back, the magnetic gap on sensor could be affected by the metal and might be easier to trip that way. (or if the magnet is already installed at the edge of the gap)
This could also occur from a strong wind if the door has enough movement to it.
If there was no physical presence at the door, we could explore the possibility of the door or magnetic rod interfering. Would you might posting a photo of the sensor as it is installed and the door is closed? We can probably tell pretty quickly if it might be the culprit.
No pets but we have little kids. I think it’s odd that door was closed and deadbolted. Could be my son isn’t giving the whole truth (he’s only 4), or maybe he was sleep walking, but again, find it odd he’d re-deadbolt and run back to bed.
When you say this (below), does that mean when the alarm sounded (and after I disarmed), the door (or sensor) was reporting open?
the telling details are that the door was opened and closed quickly, then appears to have opened again very shortly after before another open would register in history, because the next signal I see from it is another closed status a few minutes later after the alarm.
When you say this (below), does that mean when the alarm sounded (and after I disarmed), the door (or sensor) was reporting open?
No, based on Alarm.com the sensor reported Open/Close (which means the open was of short duration) and then later after the alarm it reported close, without an open confirmed in between. Usually this means that the sensor was opened and closed rapidly multiple times.
Keep in mind when I say the sensor was opened and closed rapidly that does not mean the door needs to have fully opened and closed rapidly.
Magnetic interference or the sensor at the edge of its magnetic gap along with slight door movement can account for this. Can you post an image of the sensor as it is mounted to be sure?
See image
Ah, I was anticipating a surface contact. Well, magnetic gap would not be an issue in that case, the sensor looks like it is lined up just fine.
The concern would be what part of that curtain rod is magnetic? Is that a metal door?
If the door is metal, signaling can be affected, and if the large base of the curtain rod hook is magnetic, it may indeed cause issues.
How long has the sensor been installed? You may also wish to replace the battery in the sensor.
The big white rectangle has a magnet underneath. It is a steel door. Alarm has been installed for about 2 years and this is the first false alarm we’ve had.
The time it has been installed can be a bit of a trap, because lowering battery levels can affect signaling and the metal door can affect signaling for recessed contacts, as well as affect the magnetic gap. Is the magnet in the door or is the sensor in the door?
Sensor is in the door, there wasn’t enough space between door jamb and bricks to put the whole sensor length into the jamb side. The sensor is about 15 feet from alarm panel. similar metal door install in basement, which that door is on another floor of the house and about 30 feet away (never any basement door issues).
What is easy way to check battery levels? or just need to replace?
The best way to test would be to use a multimeter tool but in this case it is likely that you need to replace the battery.
If in need of a replacement battery, you will want to ensure you use the exact type specified. If this is the 2GIG-DW20R-345, you would want a 3v lithium CR-2
As this sensor is installed in a steel door, you may need to replace your battery more frequently than other sensors to ensure optimum signalling. This would also depend on usage.
If possible, you may wish to move the curtain rod hook away from the sensor as much as possible to ensure that the magnetic base does not affect signalling.
