Viessmann VITOCROSSAL 200 Service Instructions Manual page 63

Fault codes
(cont.)
Displayed System characteris-
fault code tics
F F9 Varying fan speed
F F9 No fan feedback
F FA Fan runs without de-
mand; burner control
unit in a fault state
F Fb Burner does not start Excessive com-
F Fb Burner does not start Motorised flue gas
F Fb Burner does not start Motorised flue gas
Cause
Fan faulty, ca-
ble"a-ÖA" faulty or
broken. Check ca-
ble "a-ÖA"; check
external power
supply; replace the
cable or fan; re-
move foreign bod-
ies
Fan faulty, external
fan power supply
not connected or
faulty, cable
"a-ÖA" faulty or
broken, fan
blocked (poss. by
foreign bodies)
Fan does not reach
idle state, cable
"a-ÖA" faulty, fan
faulty, faulty burner
control unit
bustion chamber
pressure (LDW2);
condensate back-
up or condensate
path blocked off
damper connected
but not configured;
fault shutdown
damper does not
open or close
Troubleshooting
Measures
Check cable, possibly re-
place cable "a-ÖA" or
fan
Check cable "a-ÖA",
check external power
supply, replace cable or
fan, remove foreign bod-
ies
Fan subject to wind influ-
ence, check flue outlet
and fan, replace ca-
ble "a-ÖA", replace fan,
replace burner control
unit
Check condensate drain
and condensate path for
blockages
Configure the motorised
flue gas damper (flue gas
cascade); see page 54
Check the motorised flue
gas damper
63