Viessmann Vitocrossal 300 Service Manual page 79

Vitocrossal 300 CU3A 26 to 57 Service
Fault Codes
(continued)
Fault code on display
10
18
30
38
40
44
48
4C
50
58
90
91
92
93
94
98
99
*1 Control mode:
Burner in fault mode: Boiler control requires manual reset before burner can resume operation.
Burner blocked:
System behavior*1
Boiler operates based on outdoor
temperature of 32°F (0°C)
Boiler operates based on outdoor
temperature of 32°F (0°C)
Burner blocked
Burner blocked
Mixing valve closes
Mixing valve closes
Mixing valve closes
Mixing valve closes
No DHW heating
No DHW heating
Control mode
Control mode
No solar DHW heating
Control mode
No solar DHW heating
Control mode
Control mode
Boiler/burner fully operational (fault code must be verified and reset).
If fault cause is corrected, burner resumes operation.
Cause
Short circuit on outdoor
temperature sensor
Outdoor temperature
sensor cable broken
Short circuit on boiler
water temperature
sensor
Boiler water temperature
sensor cable broken
Heating circuit 2 with
mixing valve supply
short circuit on
temperature sensor
Short circuit, supply
temperature sensor,
heating circuit 3
(with mixing valve)
Heating circuit 2 with
mixing valve supply
temperature sensor
cable broken
Supply temperature
sensor cable broken
circuit 3 (with mixing
valve)
Short circuit on DHW
tank temperature sensor
Tank temperature
sensor cable broken
Short circuit,
temperature sensor /
Short circuit,
temperature sensor aÖ
Short circuit, collector
temperature sensor
Short circuit, tank
temperature sensor
Short circuit, tank
temperature sensor
Lead break, temperature
sensor /
Lead break, temperature
sensor aÖ
Troubleshooting
Corrective action
Check the outdoor temperature
sensor (see page 86).
Check the outdoor temperature
sensor (see page 86).
Check the boiler water
temperature sensor
(see page 87).
Check the boiler water
temperature sensor
(see page 87).
Check the supply
temperature sensor
(see page 87).
Check supply temperature
sensor (see page 87).
Check the supply temperature
sensor (see page 87).
Check supply temperature
sensor (see page 87).
Check the DHW sensor
(see page 87).
Check the sensor (see page 87).
Check sensor / on solar
control module
Check sensor aÖ on solar
control module
Check temperature sensor
& on solar control module or
Vitosolic sensor
Check temperature sensor at
connection S3 to Vitosolic 100
Check temperature sensor % on
solar control module or Vitosolic
sensor
Check sensor / on solar
control module
Check sensor aÖ on solar
control module
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