Fire sliding door randomly closing

Problem:

Kaefer fire sliding door randomly closing and the LED above the door indicates no alarm.

Solution:

This issue is almost always caused by the bad backup battery.

The battery is located inside the control box above the door.

After replacing the battery, it is necessary to perform learning procedure for the door.

Remove one of the terminals from the 300°C temperature fuse and attach it back after a few seconds.

Close the door by hand.

After the door is closed, pull the door knob down and release.

The door will open.

After the door opens completely, indication LED should flash green continuously.

This means learning procedure was successfully done and there are no alarms present.

Learning procedure can be seen in this video.