Viessmann Vitotronic 300 Installation And Service Instructions Manual page 41

Vitotronic 300, GW5B Installation and Service
Fault Codes
(continued)
Displayed System characteristics
fault code
51 With primary store system:
DHW tank heating is started
and stopped by DHW tank
temperature sensor 1.
52 Control mode
58 DHW tank primary pump "ON":
Set DHW temperature = Set
boiler water temperature.
Priority control is cancelled.
or
With primary store system:
DHW tank heating is started
and stopped by DHW tank
temperature sensor 2.
59 With primary store system:
DHW tank heating is started
and stopped by DHW tank
temperature sensor 1.
5A Control mode
60 Boiler at maximum temperature.
68 Boiler at maximum temperature.
70 Control mode
78 Control mode
Cause
Short circuit, DHW tank
temperature sensor 2.
Short circuit, supply temperature
sensor low loss header.
Lead break, DHW tank
temperature sensor 1.
Lead break, DHW tank
temperature sensor 2.
Lead break, low loss header
supply temperature sensor.
Short circuit, temperature
sensor aJA.
Lead break, temperature
sensor aJA.
Short circuit, temperature
sensor aJB.
Lead break, temperature
sensor aJB.
Troubleshooting
Measures
Check the DHW tank
temperature sensor
(see page 84).
Check supply temperature
sensor (see page 84).
Check DHW tank temperature
sensor (see page 84).
Check DHW tank temperature
sensor (see page 84).
Check supply temperature
sensor (see page 84).
Without supply temperature
sensor:
Set code "52:0" in the
"General" group.
Remove temperature sensor.
Set code "4A:0" in group 1
"General".
Remove temperature sensor.
Set code "4A:0" in group 1
"General".
Check temperature sensor (see
page 84).
Check temperature sensor
(see page 84).
Without temperature sensor:
Set code "4B:0" in the "General"
group.
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