53
5584 109 - 10
Vitocrossal 200 CM2 186 to 311 Service
Troubleshooting
Fault Codes
(continued)
Internal system fault
Internal system faults are created if a correct program sequence can no longer be guaranteed.
Displayed
Fault Code
System Characteristics
Cause
Measures
FD
Fault within burner
control unit
No gas, exhaust recirculation, fan
not operating, air pressure sensor
defective
Check each component, reset burner
control unit. Replace the burner
control unit if the fault persists.
Displayed
Fault Code
System Characteristics
Cause
Measures
F F9
Varying fan speed
Fan faulty, cable
“
a-Ö
A“ faulty or
broken
Check cable; replace cable
“
a-Ö
A“ or
fan if required
F F9
No fan feedback
Fan faulty; external power supply to
fan not connected or faulty; cable
“
a-Ö
A“ faulty or broken; fan blocked
(possibly by a foreign object)
Check cable “
a-Ö
A“, check external
power supply; replace cable or fan;
remove foreign object
F FA
Fan runs without demand;
burner control unit in a
fault state
Fan has not stopped; cable
“
a-Ö
A“
faulty; fan faulty; burner control unit
faulty
Wind influence on fan; check flue
outlet and fan; replace cable
“
a-Ö
A“,
replace fan; replace burner control unit
F Fb
Combustion chamber
pressure too high; burner
control unit in a fault state
Flue gas path or condensate path
blocked off
Check flue gas path or condensate
path and clean if required
Motorized vent damper not
configured with control (if used)
See flue gas damper setting
(common vent system)
Fault Cause
Measures
Combustion fault
through pulsation
Excessive gas input
Adjust gas input in accordance with rated boiler heating output
Insufficient or excessive air
Condensate build up in flue
system
Check condensate drain.
Check flue outlet and flue system.
Incorrect flue outlet
Thermo-acoustics/
combustion noise
Incorrect CO
2
settings;
insufficient or excessive air
Adjust burner in accordance with the details on page 15.
CO
2
content too
low
Incorrect setting
Check that burner has been adjusted for the correct gas type,
and change gas restrictor if required (see from page 9).
Adjust burner in accordance with the details on page 15.
CO is formed or
burner is very sooty
Insufficient or excessive air Adjust correctly. Check ventilation of installation room.
Insufficient draught in flue
system
Check flue system.
Flame extinguishes
during operation
Inlet strainer of gas valve
contaminated
Remove flange and clean strainer.
Excessive flue gas
temperature
Excessive gas throughput
Adjust gas throughput in accordance with rated boiler heating
out-put. Check condition of secondary heating surfaces of the
boiler, and clean if required.
Faults Without Fault Display