Viessmann VITODENS 200 Start-Up And Service Instructions page 31

Cause of fault
Short circuit – outdoor temperature sensor
Open circuit – outdoor temperature sensor
Short circuit – low-loss header temperature sensor
Open circuit – low-loss header temperature sensor
Short circuit – boiler temperature sensor
Open circuit – boiler temperature sensor
Short circuit – supply temperature sensor
Open circuit – supply temperature sensor
Short circuit – tank temperature sensor
Open circuit – tank temperature sensor
Internal BUS fault
Corrective action
Check outdoor temperature sensor (see page 40).
Check outdoor temperature sensor (see page 40).
Check supply temperature sensor (see page 40).
Check supply temperature sensor (see page 40).
Check boiler temperature sensor (see page 40).
Check boiler temperature sensor (see page 40).
See Installation Instructions Mix. Valve Actuator.
See coding address "000" (see page 49).
See coding address "0B8" (see page 56).
See Installation Instructions Mix. Valve Actuator.
See coding address "000" (see page 49).
See coding address "0B8" (see page 56).
Check tank temperature sensor (see page 41).
See coding address "000" (see page 49).
See coding address "0B8" (see page 56).
Check tank temperature sensor (see page 41).
See coding address "000" (see page 49).
See coding address "0B8" (see page 56).
Replace VR20 (see page 61).
Replace LGM 29 (see page 62).
Replace entire control console.
Troubleshooting
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