Viessmann VITOTRONIC300 Installation And Service Instructions Manual page 69

Vitotronic 300, GW2B Installation and Service
Fault Display
(continued)
Fault codes
Displayed System characteristics
fault code
0F Control mode.
10 Controls as if the outside
temperature was 32°F (0°C)
18 Controls as if the outside
temperature was 32°F (0°C)
19 Controls as if the outside
temperature was 32°F (0°C)
30 - With DHW tank:
Circulation pump for DHW tank
heating on; boiler is maintained
at set DHW tank temperature.
- Without DHW tank:
Boiler is regulated by the
temperature controller.
38 - With DHW tank:
Circulation pump for DHW tank
heating on; boiler is maintained
at set DHW tank temperature.
- Without DHW tank:
Boiler is regulated by the
temperature controller.
40 Mixing valve is being closed.
Cause
Service "0F" is only
displayed in the fault
history.
Short circuit, outside
temperature sensor
Lead break, outside
temperature sensor
Communication fault,
outside temperature
sensor RF
Short circuit, boiler water
temperature sensor
Lead break, boiler water
temperature sensor
Short circuit, supply
temperature sensor,
heating circuit with
mixing valve M2
(heating circuit 2)
Troubleshooting
Measures
Service required.
Note: After the service, set code "24:0"
Check the outside temperature sensor
(see page 125).
Check the outside temperature sensor
(see page 125).
Check the wireless connection (place
the outside temperature sensor RF close
to the wireless base). De-register and
then re-register the outside temperature
sensor.
Replace if necessary (see separate
installation and service instructions).
Check the boiler water temperature
sensor (see page 124).
Check the boiler water temperature
sensor (see page 124).
Check the supply temperature sensor
(see page 124).
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