Viessmann VITOTRONIC 200 Installation And Service Instructions Manual page 49

Vitotronic 200, HO1B and 300-K, MW2C Installation/Service
Fault Codes
(continued)
Fault codes
Displayed fault code System characteristics
78 With tank loading system:
Mixing valve primary circuit
"Closed"; no DHW heating
84 Control mode
85 Control mode
86 Control mode
87 Control mode
8C Control mode
8d Control mode
8E Control mode
8F Control mode
90 Control mode
91 Control mode
92 No solar DHW heating.
93 Control mode
Cause
Lead break, temperature
sensor aJB
Service or fault on
Vitotronic 200 of boiler 1
Service or fault on
Vitotronic 200 of boiler 2
Service or fault on
Vitotronic 200 of boiler 3
Service or fault on
Vitotronic 200 of boiler 4
Communication fault
Vitotronic 200 of boiler 1
Communication fault
Vitotronic 200 of boiler 2
Communication fault
Vitotronic 200 of boiler 3
Communication fault
Vitotronic 200 of boiler 4
Short circuit, temperature
sensor /, connection to
solar control module.
Short circuit, temperature
sensor aÖ, connection to
solar control module.
Short circuit, collector
temperature sensor,
connection, temperature
sensor & at solar control
module or sensor at S1 of
the Vitosolic.
Short circuit, temperature
sensor, connection at S3
of the Vitosolic.
Troubleshooting
Measures
Check temperature sensor
(see page 105)
Without temperature sensor:
Set code "4b:0" in the
"General" group.
Check service display
or fault message on the
respective Vitotronic 200
Check service display
or fault message on the
respective Vitotronic 200
Check service display
or fault message on the
respective Vitotronic 200
Check service display
or fault message on the
respective Vitotronic 200
Check and replace cascade
communication module and
connecting cable if required
Check and replace cascade
communication module and
connecting cable if required
Check and replace cascade
communication module and
connecting cable if required
Check and replace cascade
communication module and
connecting cable if required
Check temperature sensor /
(see separate installation and
service instructions).
Check temperature sensor aÖ
(see separate installation and
service instructions).
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).
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