Viessmann MatriX Service Instructions Manual page 25

Gas burner control unit
Display
Operating display in
standard mode
Operating display for
operations deviating
from the standard
condition
Service display
Fault display
Display Operating condition
Status
0 No heat demand
Standby
1 Heat demand
System tests
Start−up decision
2 Idle state check
Fan ramp up
3 Pre−purge
4 Pre−ignition
5 Safety period
7 Operation
8 Post−purge
Initial start−up, inspection and maintenance
(cont.)
Status
(single digit)
For the actual operating
condition, see the
following table
Fault code "A" or "L"
see following table
Fault code "d"
see following table
Fault code "F"
see following table
display flashes
Service
(two digit)
Display "FL" if a
flame signal is
present
Actual level of
modulation
Fault code
Display flashes
see pages 33 to 36
Display Fault code
Status
A Lack of gas
d Control stop; function
active
F Fault
L Air pressure limiter
standby position/flue gas
backup
P Parameter mode
See
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