Viessmann Vitocrossal - Troubleshooting (cont.); Fault Code Explanations (cont.)

74
Fault code dis-
played
System characteristics Cause Measures
FE Burner blocked or in a fault
state
Coding card or main PCB
faulty, or incorrect coding
card
Press reset button R. If fault per-
sists, check the coding card and
replace coding card or control unit
if necessary.
FF Burner blocked or in a fault
state
Internal fault or reset but-
ton R blocked.
Restart the appliance. Replace the
control unit if the appliance will not
restart.
Increase the water pressure or re-
set the combustion chamber pres-
sure limiter.
Troubleshooting
Fault codes (cont.)
5839829
Diagnosis