How to replace the battery in a Honeywell Recessed Door/Window Sensor
Locate the sensor that has a low battery by verifying the zone number, and location of that sensor on the alarm panel.
Place the alarm panel in Walk Test mode.
Go to the sensor on the door.
Locate the lid of the sensor.
Using a flatblade screwdriver, open the sensor by turning it counterclockwise using the screwdriver. Once it comes loose, remove it from the sensor.
Pull the sensor out of the housing. (Use sharp-nose pliers if you cannot reach it)
With the sensor removed, you can now see the battery that needs to be replaced.
Remove the old battery from the sensor, by pulling it straight up out of the battery tray.
Now that the battery has been removed from the sensor, replace it with a new AAA battery.
Pay close attention to the orientation of the battery in the battery tray. The battery will have a positive side, and a negative side, and the battery tray will have the proper orientation marked.
Once the battery has been replaced, you will need to replace the sensor inside the housing, push the sensor back into the housing making sure it is installed in the same direction it was installed to start.
Install the lid of the sensor back in its place making sure that the tabs line up properly, then secure it by using your screwdriver to turn the lid clockwise securing it in place.
Now that the lid of the sensor is properly secured onto the sensor, we will want to reboot the panel.
Once the panel has been rebooted, test the sensor by opening the sensor that was affected. If no Low Battery returns, the sensor has been fixed. If the Low Battery returns, the sensor may need to be replaced, at this point contact our Tech Support department.
False alarm on Honeywell Recessed Door/Window Sensor
If your Door/Window sensor is causing false alarms while the alarm system is armed, it is usually caused by the magnet being too far away from the sensor. This is an issue, because the magnet needs to be within range of the sensor for it to read properly. Sometimes it can be just far enough that it will work most of the time, but occasionally cause false alarms. To fix this, remove the magnet for the sensor from where it is installed, and reinstall it closer to the sensor. If you do not know how to do this contact our Technical Support department for assistance.
Honeywell Recessed Door/Window Sensor not showing closed
If the 5818MNL recessed sensor is saying that it is open on the panel, it is most likely that the sensor and the magnet are too far apart. Make sure that the gap between the magnet in the door, and the sensor in the jomb is less that ¼ of an inch. If this gap is larger than that, it may not function properly. If the gap is ok, and the sensor still is not working properly, contact our Technical Support department.
Loss of supervision on Honeywell Recessed Door/Window Sensor
If a 5818MNL recessed door/window sensor is showing a loss of supervision, this means that for whatever reason, the sensor is not being monitored by the alarm panel. To ensure that the sensor is being monitored properly perform the following troubleshooting steps:
Perform a walk test on the sensor.
If this sensor has a history of low battery, the battery may have died completely, and is no longer being monitored as it no longer has power. If this is the case, replace the battery in the sensor. If you do not know how to do this click here.
Ensure that the sensor is within range of the panel. It needs to be within 150 feet of the panel, with minimal interference, (walls, doors, etc.) If the signal strength is the issue, you can confirm that by performing a Go no Go test. If you do not know how to do this contact our Technical Support department for assistance.
If none of these reasons explain the loss of supervision of the sensor, you will need to contact our Technical Support department for assistance.