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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
9b
Control mode
Lead break, temperature sensor,
connection to S3 of the Vitosolic.
Check sensor at the solar control
unit (see separate installation and
service instructions).
9c
No solar DHW heating.
Lead break, DHW tank temperature
sensor, connection of
temperature sensor
%
at solar
control module, type SM1 or
sensor at S2 of the Vitosolic.
Check sensor at the solar control
unit (see separate installation and
service instructions).
9e
Control mode
No supply rate in solar circuit or
flow rate too low, or temperature
limiter has responded.
Check solar circuit. Acknowledge
fault message (see separate
installation and service
instructions).
9f
Control mode
Fault, solar control module, type
SM1 or Vitosolic.
Displayed if a fault occurs at
these devices that has no fault
message in the Vitotronic.
Check solar control unit (see
separate installation and service
instructions).
a0
Boiler cools down
Fault, safety equipment at “X7”
of plug-in adapter 2 for external
safety equipment
Check safety equipment, reset if
required.
a1
Boiler cools down
Fault, safety equipment at “X3”
of plug-in adapter 2 for external
safety equipment
Check safety equipment, reset if
required.
a2
Boiler cools down
Fault, safety equipment at “X2”
of plug-in adapter 2 for external
safety equipment
Check safety equipment, reset if
required.
a3
Boiler cools down
Fault, safety equipment at “X1”
of plug-in adapter 2 for external
safety equipment
Check safety equipment, reset if
required.
a7
Control mode
Programming unit fault
Replace the programming unit.
ab
Control mode, DHW tank may be
cold
Tank loading system configura-
tion fault:
Coding “55:3” in the “DHW”
group has been set, but plug
aJ
B
is not plugged in and/or
codes “4c:1” and “4e:2” in the
“General” group have not been set.
Insert plug
aJ
B
and check
codes.
b1
Control mode
Communication error,
programming unit
Check connections, and replace
the programming unit if required.
b5
Control mode
Internal fault
Check PCB is plugged in
correctly.
