Weinmann BiLevel ST 22 Operating Instructions Manual page 40

Change the fine dustfilter
Filter change indicator
Reset the filter change display
After you have changed the fine filter, you must reset the filter change display. This
is also necessary if the filter has been changed before the 1000 operating hours
have elapsed, in which case the filter change symbol does not appear in the display.
40
Maintenance
The fine dust filter must be changed when it becomes
dark and discolored and at least every 1000
operating hours. In the latter case the message "Please
change filter" appears on the display when the unit is
turned on.
Acknowledge the message by pressing the alarm
acknowledgement
then remains
filter, proceed as follows:
1. Press on the lock of the filter compartment lid and
remove the lid.
2. Replace the fine filter with a new fine filter
WM 15026. Dispose of the old filter in the
normal domestic waste.
3. Then put the filter compartment lid lower edge first
into the encasing section. Then press the filter
compartment lid into the housing until it locks into
position.
1. To reset the filter change display, press the menu
key when the device is switched on and,
the dial select the
Menu. Press the dial to call up the "Filter Change"
menu.
key. The change filter symbol
in the status line. To change the fine
item in the Patient
Filter change
using