Reasons Why the Wired Alarm Contact on a Door May Not Work

In this video, Joe explains why a hardwired door or window contact may not be working properly. One of the most common reasons is because the sensor and magnet are not aligned properly. Another possibility is that the sensor was not wired properly or because the wire from the senor has been damaged.

Door and window contacts are some of the easiest sensors to use with security systems. They consist of two parts, which are a larger sensor and a smaller magnet. The sensor is installed on the door or window frame, while the magnet is installed on the moving part of the door or window. There is a small metal reed switch inside the sensor. When the magnet is separated from the sensor, the metal reed switch is released. The sensor then knows to let the system know that the door or window has been opened.

With a wired door and window sensor, you need to run a wire from the alarm control panel to the sensor. If the wire ever becomes cut or damaged, then it will prevent the sensor from working properly. In that case, you would need to replace the wire with a new one. Another possibility for a faulty door and window contact is that the sensor and magnet are not properly aligned. If that happens, then the reed switch will remain released even when the door or window is closed.

You must remember to test a door and window contact sensor after one has been installed. This is the best way to make sure that the sensor and magnet are properly aligned. You must also make sure that the sensor and magnet are close enough together. Most door and window contacts will allow for a maximum magnet spacing gap of one-half to three-quarters of an inch. This will depend on the sensor itself, the strength of the magnet, and the type of surface the sensor is mounted on.

[herpderp]

Should be mentioned that the reed in the sensors can get stuck/magnetized closed. Symptom of this is when the door/window is opened, the alarm does not chime or start timing for disarm code. You can tap/smack/hit the sensor a few times with the back of a screwdriver (not very hard) and if it starts working again, replace the sensor.

[wyattwashington]

My window contact had been showing open for nearly a month and I hadn't been setting my alarm. I was planning on calling an alarm company to repair it. Thanks to your excellent explanation on how to troubleshoot it, I was able to resolve the problem myself. (One of the wires to the window contact was no longer connected properly.) It was quite simple to repair as you explained and took me less that 5 minutes to resolve. Thanks a million for your video.

[chessu]

I had to re-install all the hardwire contact sensors after a new window installation, I bought the replacements but my question is: does the color code have to have a specific input in the wire sensors, do they have a polarity sensor like electricity (negative vs positive). I have experience with installation since I work for telecommunication ISP

[michalispindarou]

Thanks for the video I have a door-wired sensor and it failed two to three times. Have in mind that when that happens the sensor shows open door No contact. The weird thing here is that I removed it to check the wires' contact(( there were tied )) suddenly worked for a couple of months but it has failed again! I did the same now it's ok. What do you think as an expert to do?

[bl]

I have four window contacts all connected to the same zone. How do I test which of the contacts/wires aren’t working?

[thomasj.dubberly]

Can that contact switch be used outdoors ? If not do you know of one that could ? I'm trying to install a blinking light on an automatic gate. Thanks

[ricktech]

Where can I buy both contacts? I can't find at Home Depot .

[Rfinnshw]

👍Joe, Great video! Thanks for this helpful information.

[lfstudio]

Troubleshooting mine right now. My honeywell system stopped alerting me when a door opens. Anyone have this problem?

[Tieupp]

What will happen if I just take off the sensors? Will the sensors just stop working or can the tamper alarm go off and how do I stop that if possible?

[joshuagriffin]

If the resistor ius at the panel go to the lat one in line twist the wires to gether then test. if still faulted move to the next one until you locate the bad device

[Rick-tbso]

I closed the basement door and they alarm went off, could the door alarm senor be the fault ??

[macrossman]

Is it possible the magnet has lost its strength?

[maryjohnson]

How can I reset my door to say front door if I open front door of if I open back door to say back door