26
7.
Fault
7.1 Fault analysis
If the control system recognises a fault, this is
shown on the display by a number with an "F"
in front of it. If a 3-way switch with filter status
display is installed, the LED on the 3-way
switch also starts to flash.
The fault
F9
is shown here as an example.
That means that there is a fault in the cabling
to the outside temperature sensor or in the
sensor itself.
The unit stays in fault mode until the corre-
sponding problem has been resolved. Then
the unit carries out an automatic reset
(Autoreset) and the display reverts to opera-
tional mode.
The table in section 7.3 contains an overview
of the faults, the possible causes and the
measures that need to be taken.
7.2 Filter status display
If the message "
FIL
" appears in the display,
the filters have to be exchanged.
After changing the filters, the filter status
display has to be reset by pressing the "
OK
"
button.
The display "
FIL
" flashes briefly and then the
display reverts to operational mode.
