Fault Codes - Viessmann VITOTRONIC 300 Installation And Service Instructions Manual

Troubleshooting, Vitotronic 300-K

Fault Codes

Displayed System characteristics
fault code
10 Activates at 32 °F (0° C)
outside temperature.
18 Activates at 32 °F (0° C)
outside temperature.
20 Stand-alone control unit without
supply temperature sensor (poss.
supply temperature not high
enough).
28 Stand-alone control unit without
supply temperature sensor (poss.
supply temperature not high
enough).
40 Mixing valve is closed.
44 Mixing valve is closed.
48 Mixing valve is closed.
4C Mixing valve is closed.
50 DHW tank primary pump "ON":
Set DHW temperature = set
supply temperature
Priority control is cancelled.
or
With primary store system:
DHW tank heating is started
and stopped by DHW tank
temperature sensor 2.
51 With primary store system:
DHW tank heating is started
and stopped by DHW tank
temperature sensor 1.
58 DHW tank primary pump "ON":
Set DHW temperature = set
supply 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.
56
Vitotronic 300, GW5B & MW1B Installation and Service
Cause
Short circuit, outside temperature
sensor
Lead break, outside temperature
sensor
Short circuit, common supply
temperature sensor
Lead break, common supply
temperature sensor
Short circuit, supply temperature
sensor, heating circuit with mixing
valve M2 (heating circuit 2)
Short circuit, supply temperature
sensor, heating circuit with mixing
valve M3 (heating circuit 3)
Lead break, supply temperature
sensor, heating circuit with mixing
valve M2 (heating circuit 2)
Lead break, supply temperature
sensor, heating circuit with mixing
valve M3 (heating circuit 3)
Short circuit, DHW tank
temperature sensor 1
Short circuit, DHW tank
temperature sensor 2
Lead break, DHW tank temperature
sensor 1
Lead break, DHW tank temperature
sensor 2
Measures
Check outside temperature
sensor (see page 110).
Check outside temperature
sensor (see page 110).
Check supply temperature sensor
(see page 110).
Check supply temperature sensor
(see page 110).
Check supply temperature sensor
(see page 110).
Check supply temperature sensor
(see page 110).
Check supply temperature sensor
(see page 110).
Check supply temperature sensor
(see page 110).
Check the DHW tank
temperature sensor
(see page 110).
Check the DHW tank
temperature sensor
(see page 110).
Check the DHW tank temperature
sensor (see page 110).
Check the DHW tank
temperature sensor
(see page 110).