Why Is My 5816 Showing a Fault When My Window is Closed?

Your 5816 is showing a fault when your window is closed because the magnet is not properly aligned with the sensor. The zone will show a fault when the sensor's internal reed switch is released due to the magnet not being present. Adjusting the sensor and magnet alignment can fix the issue.

When using a door and window contact like the Honeywell 5816, you must make sure that the sensor and magnet are properly aligned. This is important for ensuring that the zone restores when your window is closed. If the sensor and magnet are not properly aligned, then the zone will continue to appear "faulted", and the system will think that the window is still open. Fortunately, this issue can almost always be fixed by simply adjusting the alignment of the window sensor and its magnet.

The Honeywell 5816 is one of the most popular door and window sensors available, and it is very easy to use. The larger sensor portion of the 5816 should be mounted on the window frame. The smaller magnet should be mounted on the moving part of the window. The sensor and magnet should be aligned so that the side of the sensor with the indentations is facing the magnet. The magnet should be positioned so that lines up directly with the two (2) indentation marks on the 5816.

The indentations for the 5816 can be seen in the picture below. Note that the picture features the brown 5816, also known as the 5816WMBR. The standard white model will have similar indentations. Just make sure the magnet lines up between these two markers and that the indentations are facing the magnet.

You must also consider the magnet spacing gap for the 5816 sensor. The 5816 sensor and its magnet should be close enough together that the sensor's internal reed switch closes when the window is closed. Ideally, the sensor and magnet should be in direct contact when the window is closed. This is why the sensor is often referred to as a door and window "contact".

The maximum magnet spacing gap is about 3/4" when mounted on a metal surface, and about 1 1/4" when mounted on a wooden and non-magnet surface. Trying to use a magnet spacing gap larger than those recommended distances will likely result in the zone showing a fault all the time, even when the window is closed. This is why it is always important to test a door and window sensor after installation!