Function Warnings; Battery Warning - HumanTechnik lisa Mode D'emploi

12. Function warnings

The signolux smoke detector monitors its own function. Disturbances
in function are indicated in the following ways:
Function warning:
Every 48 seconds the control LED flashes twice in red and 2 beep tones
are given: This indicates an internal error (e.g. caused by deposits of dust
on the sensor) and the detector not being able to function in a reliable
way.

Battery warning:

Every 48 seconds the control LED flashes once in red and 1 beep tone is
given: This indicates that the inbuilt battery is approaching its end of life.
For your safety, the smoke detector should be replaced in both
cases.
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