Viessmann VITOTRONIC300 Installation And Service Instructions Manual page 76

Troubleshooting
Fault Display
(continued)
Displayed System characteristics
fault code
CF Control mode.
No communication via
LON.
d1 Boiler cools down
d2 Control mode.
d3 Control mode.
d4 Boiler cools down
d6 Control mode.
d7 Control mode.
d8 Control mode.
dA Control mode without
room influence.
db Control mode without
room influence.
dC Control mode without
room influence.
dd Control mode without
room influence.
dE Control mode without
room influence.
dF Control mode without
room influence.
Note: In case of participant faults, "Fault participant" ... is displayed.
76
Cause
Communication fault, LON
communication module of control unit
Burner fault
Communication error 2, plug-in
adaptor for external safety equipment
Communication error, extension EA1
The high limit safety cut-out has
responded or fuse F2 has blown
Input DE1 at extension EA1 reports
a fault
Input DE2 at extension EA1 reports
a fault
Input DE3 at extension EA1 reports
a fault
Short circuit, room temperature
sensor, heating circuit without mixing
valve A1 (heating circuit 1)
Short circuit, room temperature
sensor, heating circuit with mixing
valve M2 (heating circuit 2)
Short circuit, room temperature
sensor, heating circuit with mixing
valve M3 (heating circuit 3)
Lead break, room temperature sensor,
heating circuit without mixing valve
A1 (heating circuit 1)
Lead break, room temperature sensor,
heating circuit with mixing valve M2
(heating circuit 2)
Lead break, room temperature sensor,
heating circuit with mixing valve M3
(heating circuit 3)
Vitotronic 300, GW2B Installation and Service
Measures
Check LON communication module
and replace if required.
If no LON communication module
is installed, set code "76:0" in
"General" group.
Check the burner
Check plug-in adaptor .
Without plug-in adaptor:
Set code "31:0" in the "General" group
Check connections (see page 127).
Without extension EA1:
Set code "5b:0" in the "General" group.
Check the high limit safety cut-out
or the burner, burner loop and fuse F2.
Remove fault at appliance concerned.
Remove fault at appliance concerned.
Remove fault at appliance concerned.
Check the room temperature sensor
(see page 124).
Check the room temperature sensor
(see page 124).
Check the room temperature sensor
(see page 124).
Check room temperature sensor
(see page 124)
Check room temperature sensor
(see page 124)
Check room temperature sensor
(see page 124)