Viessmann Vitocrossal 300 CA3 2.5 Installation And Service Instructions Manual page 180

Troubleshooting
Boiler System Fault Codes
Displayed System characteristics
fault code
9b Control mode
9c No solar DHW heating.
9e Control mode
9f Control mode
a0 Boiler cools down
a1 Boiler cools down
a2 Boiler cools down
a3 Boiler cools down
a7 Control mode
ab Control mode, DHW tank may be
cold
b1 Control mode
b5 Control mode
180
Vitocrossal 300 CA3 Series 2.5 to 6.0 Installation/Service
(continued)
Cause
Lead break, temperature sensor,
connection to S3 of the Vitosolic.
Lead break, DHW tank temperature
sensor, connection of
temperature sensor % at solar
control module, type SM1 or
sensor at S2 of the Vitosolic.
No supply rate in solar circuit or
flow rate too low, or temperature
limiter has responded.
Fault, solar control module, type
SM1 or Vitosolic.
Displayed if a fault occurs at
these devices that has no fault
message in the Vitotronic.
Fault, safety equipment at "X7"
of plug-in adapter 2 for external
safety equipment
Fault, safety equipment at "X3"
of plug-in adapter 2 for external
safety equipment
Fault, safety equipment at "X2"
of plug-in adapter 2 for external
safety equipment
Fault, safety equipment at "X1"
of plug-in adapter 2 for external
safety equipment
Programming unit fault
Tank loading system configura-
tion fault:
Coding "55:3" in the "DHW"
group has been set, but plug
aJB is not plugged in and/or
codes "4c:1" and "4e:2" in the
"General" group have not been set.
Communication error,
programming unit
Internal fault
Measures
Check sensor at the solar control
unit (see separate installation and
service instructions).
Check sensor at the solar control
unit (see separate installation and
service instructions).
Check solar circuit. Acknowledge
fault message (see separate
installation and service
instructions).
Check solar control unit (see
separate installation and service
instructions).
Check safety equipment, reset if
required.
Check safety equipment, reset if
required.
Check safety equipment, reset if
required.
Check safety equipment, reset if
required.
Replace the programming unit.
Insert plug aJB and check
codes.
Check connections, and replace
the programming unit if required.
Check PCB is plugged in
correctly.