Viessmann B2HF - Page 98

98
Displayed fault
code
System characteristics Cause Measures
F.405 Burner in a fault state Ionisation electrode earth
fault, BCU burner control
unit faulty
Check IO electrode for earth fault.
If fault continues to persist, replace
BCU burner control unit (see
page 109).
Reset the appliance.
F.406, F.408,
F.410
Burner in a fault state BCU burner control unit
faulty
Replace BCU burner control unit
(see page 109).
Reset the appliance.
F.416 Burner locked out Flue gas temperature sen-
sor incorrectly positioned
Fit flue gas temperature sensor
correctly. See "Repairs".
Carry out mains reset after fault
has been remedied.
F.417, F.418 Burner in a fault state BCU burner control unit
faulty
Replace BCU burner control unit
(see page 109).
Reset the appliance.
F.425 System in control mode, cal-
culation out of operation
Time synchronisation
failed
Set the time. If external time is
used, check parameters 1504 and
508.
F.430 Control mode operation in
line with set values of heat
generator
Communication error,
gateway
Check gateway module connecting
cable and power supply.
F.446 Burner in a fault state Deviation, heat generator
flow temperature sensor/
high limit safety cut-out
Check the flow temperature sen-
sor/high limit safety cut-out.
Check plug-in connection and lead
to sensor.
Reset the appliance.
F.447, F.448 Burner in a fault state Deviation, ionisation volt-
age signal
Replace BCU burner control unit
(see page 109).
Reset the appliance.
F.449, F.450,
F.451, F.452
Burner in a fault state Error in scheduled pro-
gram run monitoring
Reset the appliance. If fault recurs,
replace BCU burner control unit
(see page 109).
F.453 Burner in a fault state Synchronisation error, se-
quence
Reset the appliance. If fault recurs,
replace BCU burner control unit
(see page 109).
F.454 Burner in a fault state Incorrect software version Flash the correct software version
for the BCU burner control unit.
F.455 Burner in a fault state Error in program run moni-
toring
Reset the appliance. If fault recurs,
replace BCU burner control unit
(see page 109).
F.456 Burner in a fault state Error in program run moni-
toring
Reset the appliance. If fault recurs,
replace BCU burner control unit
(see page 109).
F.457 Burner in a fault state Fan sluggish or blocked. Reset the appliance.
Check fan for sluggishness. In the
case of severe contamination or
grinding noises, replace fan unit.
F.458 Burner locked out Internal error Restart the heat generator. If nec-
essary, reset the appliance.
F.462 Burner in a fault state LPG safety valve (sole-
noid valve) at EM-EA1 ex-
tension does not open
(DIO electronics module).
Check solenoid valve connection
at EM-EA1 extension (DIO elec-
tronics module).
Reset the appliance.
Troubleshooting
Fault messages (cont.)
5593201
Diagnosis