Viessmann Vitocrossal 300 Service Manual page 82

Troubleshooting
Fault Codes
(continued)
Fault code on display
D8
DA
DB
DC
DD
DE
DF
E0
E1
E3
*1 Control mode:
Burner in fault mode: Boiler control requires manual reset before burner can resume operation.
Burner blocked:
82
System behavior*1
Control mode
Control mode without
room influence
Control mode without
room influence
Control mode without
room influence
Control mode without
room influence
Control mode without
room influence
Control mode without
room influence
Control mode
Burner in a fault mode
Burner in a fault mode
Boiler/burner fully operational (fault code must be verified and reset).
If fault cause is corrected, burner resumes operation.
Vitocrossal 300 CU3A 26 to 57 Service
Cause
Input DE3 reports a
fault at extension EA1
Short circuit on room
temperature sensor,
heating circuit 1 without
mixing valve
Room temperature
sensor, shorted out
heating circuit 2 with
mixing valve
Short circuit, room
temperature sensor,
heating circuit 3 (with
mixing valve)
Room temperature
sensor cable broken,
heating circuit 1
without mixing valve
Room temperature
sensor cable broken,
heating circuit 2 with
mixing valve
Room temperature
sensor cable broken,
heating circuit 3
(with mixing valve)
Fault external LON
participant
Ionization current too
high during calibration
Heat transfer too low
during calibration.
Temperature limiter
caused shutdown.
Corrective action
Remove fault at appliance
concerned.
Check the room temperature
sensor, heating circuit 1
without mixing valve.
Check the room temperature
sensor, heating circuit 2.
Check room temperature
sensor, heating circuit 3
Check the room temperature
sensor, heating circuit 1 and
the remote control setting
(see page 87).
Check the room temperature
sensor, heating circuit 2 and
the remote control settings
(see page 87).
Check room temperature
sensor for heating circuit 3
and remote control settings
(see page 87).
Check connections and LON
participants.
Check gap between ionization
electrode and burner gauze
assembly (see page 20). In open
flue mode, prevent very dusty
conditions for the combustion air.
Press reset button R.
Ensure adequate heat transfer.
Press reset button R.