Internal System Faults - Viessmann Vitocrossal 200 Service Instructions For Contractors

Fault codes
(cont.)
Fault code dis- System characteristics
played
F F9 No feedback from fan
F FA Fan runs without demand;
burner control unit in a fault
state.
F FB Burner does not start

Internal system faults

If the correct program sequence can no longer be
guaranteed, internal system faults occur.
Shown on dis- System characteristics
play
F E5, F EC, F Fault in burner control unit
Ed, F Fd, F FF area
F FD Fault in burner control unit
area
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-
Cause
Fan faulty, external fan
power supply not connec-
ted or faulty, cable "
faulty or broken, fan
blocked (poss. by foreign
bodies)
Fan does not reach idle
state, cable "
fan faulty, burner control
unit faulty
Combustion chamber
■
pressure too high
(LDW2)
Condensate backed up
■
Flue gas path blocked
■
Flue gas damper does
■
not open or close.
Burner control unit con-
■
figured incorrectly
Cause
Internal system fault and
EMC
See the following table
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
Measures
Check cable "
nal power supply, replace cable or
A" fan, remove foreign body.
a-Ö
Fan subject to wind influence,
check flue outlet and fan, replace
a-Ö A" faulty,
cable "
a-Ö
burner control unit.
Check condensate drain and flue
■
gas path for blockages.
Check flue gas damper.
■
Check motorised flue gas damp-
■
er operating parameters.
Measures
Reset burner control unit. Replace
the burner control unit if the fault
persists.
See the following table
Measure
Replace programming unit.
Check wiring.
Remove plug from fuel valve 2, reset burner con-
trol unit and check error messages. If F Fd recurs,
replace burner control unit. Otherwise, replace
fuel valve 2.
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.
Troubleshooting
A", check exter-
a-Ö
A", replace fan, replace
43