Diagnosis - Viessmann VITOCROSSAL 200 Instructions Manual

Diagnosis

Faults with indication on the display and programming unit
Message codes
Message System characteris-
code tics
A Burner OFF
A Burner OFF
F Burner is in a fault
state
L Air pressure switch
responds during
operation
N System OFF
General process errors
Fault code System characteris-
tics
20 Fan pressure is pro-
duced during the air
pressure switch idle
state check
20 Air pressure switch
contact is not in the
idle state
21 Air pressure switch
shows no air pres-
sure, fan does not
operate
21 Fan does not run
Cause
Gas pressure lim-
iter fault
Lack of gas
See fault code
Flue gas back
pressure, conden-
sate banked up
Incorrect parame-
ter set selected
Cause
Wind influence on
fan
Air pressure switch
faulty
Air pressure switch
faulty
Fan faulty; cables
are faulty or bro-
ken
Troubleshooting
Measures
Check the gas pressure
limiter
Notify your gas supply util-
ity
See fault code steps
Check condensate drain,
remove flue gas back
pressure, reset the burner
control unit in accordance
with the details on
page 33.
See acknowledging a
parameter set, page 38.
Measures
Check the flue gas
draught (chimney)
Replace the air pressure
switch
Replace the air pressure
switch
Check cables and replace
the fan if required
41