Internal System Faults; Faults Without Fault Display - Viessmann MatriX Service Instructions For Contractors

Troubleshooting
Fault codes
(cont.)
Fault code on System characteristics
display
F FA Fan runs without demand;
burner control unit in a fault
state.
F FB Excessive combustion cham-
ber pressure, burner control
unit in a fault state

Internal system faults

Internal system faults occur if a flawless program
sequence can no longer be guaranteed.
Shown on dis- System characteristics
play
F E5, F EC, F Fault in burner control unit
Ed, F Fd, F FF area

Faults without fault display

Fault
Combustion faults due to
pulsation
Thermo-acoustics/combus-
tion noise
CO content too low
2
CO formation or burner is
very sooty.
Flame extinguishes during
operation
Flue gas temperature too
high
28
Cause
Fan does not reach idle
state, cable "
fan faulty, burner control
unit faulty
Flue gas path or conden-
sate path blocked off
Cause
Internal system fault and
EMC
Cause of fault
Excessive gas throughput
Insufficient or excessive air
Condensate banked up in flue
system
Incorrect flue outlet
Incorrect CO settings; insuffi-
2
cient or excessive air
Incorrect setting
Insufficient or excessive air
Insufficient draught in flue
system
Inlet strainer of gas train con-
taminated
Excessive gas throughput
Measures
Fan subject to wind influence,
A" faulty, check flue outlet and fan, replace
a-Ö
cable "
a-Ö
burner control unit.
Check flue gas path or condensate
path and clean if required.
Measures
Reset burner control unit. Replace
the burner control unit if the fault
persists.
Steps to take
Adjust gas throughput in accordance with rated
boiler heating output.
Check condensate drain.
Check flue outlet and flue system.
Adjust burner in accordance with the details from
page 12.
Check whether the burner has been adjusted to
the correct gas type; change gas restrictor if re-
quired (see from page 7).
Adjust burner in accordance with the details from
page 12.
Correct the settings. Check ventilation in installa-
tion room.
Check flue system.
Remove flange and clean strainer.
Adjust gas throughput in accordance with rated
boiler heating output. Check secondary heating
surfaces of the boiler and clean if required.
A", replace fan, replace