On the back of the Door Sensor, you will find the tamper button. The tamper button has two functions:
Maintenance mode
Pressing the tamper button allows you to put the Door Sensor into maintenance mode and connect it to the Nuki App.
Tamper detection Assuming the installation has been done correctly, the tamper button of the Door Sensor will be permanently pressed when mounted. If the Door Sensor or mounting plate becomes loose or is removed, the tamper button will be released. This will then trigger the tamper detection and you will be notified through the Nuki App. Even if the tamper button becomes loose just a little bit, this will still activate the tamper detection.
To calibrate the Door Sensor, the tamper button must be fully pressed. If it is not, this is usually due to one of the following reasons, which can be easily resolved:
Surface/Door frame If the surface where the sensor is mounted upon is uneven, the tamper button cannot be fully pressed. To level out small irregularities, you can simply attach a piece of tape. Then mount the Door Sensor on the taped, level surface.
Adhesive pad Another cause of the tamper button not being fully pressed can be a too-thick adhesive pad. If you are not using the original adhesive pad of the sensor, check the thickness of the adhesive pad and replace it if necessary.
Mounting plate and Door Sensor Finally, it is important that the sensor and mounting plate are firmly attached to each other so that the tamper button is pressed sufficiently.
In summary, before calibrating the Door Sensor, make sure that the tamper button is and remains fully pressed. This can be achieved by optimal mounting. The mounting plate must be attached directly onto the door frame. The door frame should not have any irregularities, and the sensor and mounting plate must be firmly connected to each other.