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5790 733 - 07
Vitocrossal 300 CA3 Series 2.5 to 6.0 Installation/Service
Boiler System Fault Codes
(continued)
Troubleshooting
Displayed
fault code
System characteristics
Cause
Measures
c9
Boiler cools down.
Fault, maximum pressure limiter
at “X3” of plug-in adapter 1 for
external safety equipment
Check system pressure,
reset maximum pressure limiter.
cA
Boiler cools down.
Fault, minimum pressure limiter
or maximum pressure limiter 2
at “X2” of plug-in adapter 1 for
external safety equipment
Check system pressure,
reset minimum pressure limiter
or maximum pressure limiter 2.
cB
Boiler cools down.
Fault at additional safety
temperature limiter or
temperature monitor at “X1” of
plug-in adapter 1 for external
safety equipment
Check system temperature,
reset safety temperature limiter.
cF
Control mode
No communication via LON,
boiler at a configurable
temperature set point
Communication error, control
unit LON communication module.
Check LON communication
module and replace if required.
If no LON communication module
is installed, set code “76:0” in
the “General” group.
d1
Boiler cools down.
Burner in fault mode
Check burner
d2
Control mode
Communication fault, Plug-in
adapter 2 for external safety
equipment
Check plug-in adapter , if no
plug-in adapter is available,
adjust coding “31:0” in
“General” group.
d3
Control mode
Communication error, extension
EA1.
Check connections (see page
36). Without extension EA1:
Set code “5b:0” in the
“General” group.
d4
Boiler cools down
MCB F2 has responded.
Connection plug
aBA
broken.
Check MCB F2 and jumper on
plug
aBA
.
Fuse F2 has tripped or check
connection to Plug
aBA
, possibly
plug
aBA
not inserted.
d5
Boiler ramps up to the electronic
maximum boiler water
temperature limit.
No communication between
boiler circuit control unit and
cascade control unit.
Check communication via
participants check.
Check configuration of cascade
participants.
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 room temperature
sensor (see page 186).
db
Control mode without
room influence
Short circuit, room temperature
sensor, heating circuit with mixing
valve M2 (heating circuit 2).
Check room temperature
sensor (see page 186).
