If your proximity sensors are constantly in a state of either open or closed, this could be because there is a problem with the installation of the device.

Proximity sensors work by sensing the presence of an object.

Correctly installed sensors have a gap of no more than 5mm (3/16 inches or 0.19685 inches) between the front of the sensor and the object that it is supposed to detect.

Below is a picture that demonstrates how too much distance can actually lead to no sensor reading.

One possible solution, is to add some cardboard backing beneath the sensor to help close any gaps that may be more than 5mm (3/16 inches or 0.19685 inches).

Conversely, if the gap between the sensor and the object it is detecting is too small then you risk damaging the sensor by crushing it in the gap.

A solution to this is to find an alternative location that may have more room for example the side of the door, or the door frame.
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