Viessmann Vitovalor PT2 Installation And Service Instructions For Contractors page 116

Troubleshooting
Fault messages on the gas condensing...
Control unit System characteristics
message
F.58 Control mode without room
influence
F.59 Burner locked out
F.62 Burner in a fault state
F.63 Burner in a fault state
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 blocked.
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 Affected extension functions
in emergency mode.
116
(cont.)
Cause
Short circuit, room tem-
perature sensor
Power supply, low voltage
High limit safety cut-out
has responded.
Flue gas temperature lim-
iter has responded.
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
Measures
Check external room temperature
sensor of heating circuit or room
temperature sensor of remote con-
trol unit.
Check the power supply.
Check fill level of the heating sys-
tem. Check circulation pump. Ven-
tilate system.
Reset device.
Check fill level of the heating sys-
tem. Ventilate system.
Unlock the appliance once the flue
system has cooled down.
Check gas supply (gas pressure
and gas flow switch), gas train and
connection line.
Check ionisation electrode:
Distance to burner gauze assem-
■
bly (see page 79)
Contamination of electrode
■
Reset device.
Check ionisation electrode and
connecting cable.
Reset device.
Check ionisation electrode and
connecting cable.
Reset device.
Reset device.
Check fan on blockade.
Reset device.
Check fan.
Check connection cables on fan.
Check fan control.
Reset device.
Check CAN bus connection and
cables.
Reset device.
Top up with water.
Check software version. Flash new
version if necessary.
Reset device.
Check pump and replace if neces-
sary.
Check connections on DIO elec-
tronics module and connection to
heat management unit.