Viessmann Vitocrossal 200 Series Service Instructions Manual page 46

Troubleshooting
Fault codes
(cont.)
Detailed error codes for F FD
Detailed er- Component/signal Cause of fault
ror code
30 Reset button
31 Fuel valve 2 feed-
back
32 Air pressure switch
1
34 Gas pressure
switch 1
35 Plug 41 demand T2 High switching se-
36 Plug 90 T8
37 Plug 90 T7 SK
38 Fuel valve 1 feed-
back
3A Ignition feedback
3B Air pressure switch
2
60 Hall signal fan feed-
back (RM-N)
Faults without fault display
Fault
Combustion faults due
to pulsation
Thermo-acoustics/
combustion noise
46
Programming unit faulty
Wiring
Incorrect return voltage
(e.g., DC voltage)
Actuator faulty
High switching se-
quence, switch flutters
External voltage
High switching se-
quence, switch flutters
External voltage
quence, switch flutters
External voltage
High switching se-
quence, switch flutters
External voltage
High switching se-
quence, switch flutters
External voltage
Incorrect return voltage
(e.g., DC voltage)
Actuator faulty
Incorrect return voltage
(e.g., DC voltage)
Actuator faulty
High switching se-
quence, switch flutters
External voltage
Fan speed too high. In-
correct fan or incorrect
coding card
Cause of fault
Excessive gas throughput
Insufficient or too much air
Condensate backed up in flue
system
Incorrect flue outlet
CO setting not correct; too
2
much or too little air. Burner
gauze assembly contaminated
or faulty.
Measure
Replace programming unit.
Check wiring.
Disconnect the plug from fuel valve 2, reset the
burner control unit and check the fault messages.
If F Fd recurs, replace the burner control unit.
Check flue gas path and combustion. Check set-
ting LDW1. Check burner gauze assembly for
soiling.
Check the gas supply. Check setting GDW1 and
gas train intake screen.
Check whether external voltage present.
Check on-site connection.
Check whether external voltage present.
Check on-site connection.
Check whether external voltage present.
Check on-site connection.
Disconnect the plug from fuel valve 1, reset the
burner control unit and check the fault messages.
If fault F Fd recurs, replace the burner control
unit.
Disconnect cable from ignition module, reset
burner control unit and check error messages. If
F Fd recurs, replace burner control unit. Other-
wise, replace ignition module.
Check flue gas path and reheating surfaces.
Check air pressure switch 2 setting.
Check the fan and coding card.
Measure
Adjust gas throughput in accordance with the rated
boiler heating output.
Check condensate drain.
Check flue outlet and flue system.
Adjust burner in accordance with the details on
page 16 onwards.
Clean the burner gauze assembly with compressed
air; replace the burner gauze assembly if necessary.