Vitotronic 300, GW2B Installation and Service
5693 982 - 04
76
Troubleshooting
Fault Display
(continued)
Displayed
fault code
System characteristics Cause
Measures
CF
Control mode.
No communication via
LON.
Communication fault, LON
communication module of control unit
Check LON communication module
and replace if required.
If no LON communication module
is installed, set code “76:0” in
“General” group.
d1
Boiler cools down
Burner fault
Check the burner
d2
Control mode.
Communication error 2, plug-in
adaptor for external safety equipment
Check plug-in adaptor .
Without plug-in adaptor:
Set code “31:0” in the “General” group
d3
Control mode.
Communication error, extension EA1
Check connections (see page 127).
Without extension EA1:
Set code “5b:0” in the “General” group.
d4
Boiler cools down
The high limit safety cut-out has
responded or fuse F2 has blown
Check the high limit safety cut-out
or the burner, burner loop and fuse F2.
d6
Control mode.
Input DE1 at extension EA1 reports
a fault
Remove fault at appliance concerned.
d7
Control mode.
Input DE2 at extension EA1 reports
a fault
Remove fault at appliance concerned.
d8
Control mode.
Input DE3 at extension EA1 reports
a fault
Remove fault at appliance concerned.
dA
Control mode without
room influence.
Short circuit, room temperature
sensor, heating circuit without mixing
valve A1 (heating circuit 1)
Check the room temperature sensor
(see page 124).
db
Control mode without
room influence.
Short circuit, room temperature
sensor, heating circuit with mixing
valve M2 (heating circuit 2)
Check the room temperature sensor
(see page 124).
dC
Control mode without
room influence.
Short circuit, room temperature
sensor, heating circuit with mixing
valve M3 (heating circuit 3)
Check the room temperature sensor
(see page 124).
dd
Control mode without
room influence.
Lead break, room temperature sensor,
heating circuit without mixing valve
A1 (heating circuit 1)
Check room temperature sensor
(see page 124)
dE
Control mode without
room influence.
Lead break, room temperature sensor,
heating circuit with mixing valve M2
(heating circuit 2)
Check room temperature sensor
(see page 124)
dF
Control mode without
room influence.
Lead break, room temperature sensor,
heating circuit with mixing valve M3
(heating circuit 3)
Check room temperature sensor
(see page 124)
Note:
In case of participant faults, “Fault participant” ... is displayed.
