Not a fault. The alarm tone has been switched off in Settings mode.
To switch the alarm tone back on, proceed as follows:
Press the / button.
All available symbols are shown in the display. The symbol flashes.
Press the sensors for setting the temperature ( or ) repeatedly until the symbol flashes in the display.
Press the OK sensor to confirm your choice.
The selected setting flashes in the display. The symbol lights up.
Press the or sensors to select the following settings:
0: keypad tone off: door alarm off
1: keypad tone off: door alarm on (after 4 minutes)
2: keypad tone off: door alarm on (after 2 minutes)
3: keypad tone on: door alarm on (after 2 minutes)
Press the OK sensor to confirm your choice.
The selected setting is applied. The symbol flashes.
Press the / sensor again to exit Settings mode.
Settings mode is exited automatically after approximately one minute.
