Viessmann VITODENS 222-F Installation And Service Instructions Manual page 74

Troubleshooting
Fault messages
(cont.)
Fault number System characteristics
on the display
F.67 Burner in a fault state
F.68 Burner in a fault state
F.69 Burner in a fault state
F.70 Burner in a fault state
F.71 Burner in a fault state
F.72 Burner in a fault state
F.73 Burner in a fault state
F.74 Burner locked out.
Internal circulation pump off.
No central heating and no
DHW heating.
F.77 Burner in a fault state
F.89 No central heating and no
DHW heating.
F.91 Function of affected exten-
sion in emergency mode.
F.92 Function of affected exten-
sion in emergency mode
F.93 Function of affected exten-
sion in emergency mode.
F.94 Reheating suppression disa-
bled.
F.100 Function of the connected
electronics module in emer-
gency mode
74
Cause
Ionisation current lies out-
side the permissible range
Flame signal is already
present at burner start.
Ionisation current lies out-
side the permissible range
Internal burner control unit
fault
Fan speed too low
Fan idle state not reached Check draught in flue system.
Internal communication
error
System pressure too low
Data memory burner con-
trol unit
Internal pump blocked
DIO electronics module
communication error
ADIO electronics module
communication error
M2IO electronics module
communication error
SDIO/SM1A electronics
module communication er-
ror
Voltage error PlusBus
Measures
Check gas supply (gas pressure
and gas flow switch), gas train and
connection line.
Check ionisation electrode for the
following:
Distance to burner gauze assem-
■
bly (see page 43)
Contamination on electrode
■
Reset the appliance.
Check ionisation electrode and
connecting cable.
Reset the appliance.
Check ionisation electrode and
connecting cable.
Reset the appliance.
Reset the appliance.
Check fan for blockage.
Reset the appliance.
Check the fan.
Check the fan connecting cables.
Check the fan control.
Reset the appliance.
Check CAN bus connection and
cables.
Reset the appliance.
Top up with water.
Check software version. Flash new
version if necessary.
Reset the appliance.
Check pump and replace if neces-
sary.
Check connections on DIO elec-
tronics module and connection to
HMU heat management unit.
Check connections and cables be-
tween ADIO electronics module
and HMU heat management unit.
Check connections on M2IO elec-
tronics module and connection to
HMU heat management unit.
Check connections on SDIO/SM1A
electronics module and connection
to HMU heat management unit.
Check the PlusBus connecting ca-
ble.