Viessmann Vitocal 300-G Installation And Service Instructions Manual page 125

Control unit diagnostics
ID Message
(priority)
7B Room tem-
perature sen-
sor NC ("U")
92 Collector sen-
sor ("U")
93 Return tem-
perature sen-
sor ("U")
9A Collector sen-
sor ("U")
9B Return tem-
perature sen-
sor ("U")
A6 Secondary
pump ("U")
A7 Solar circuit
("U")
A8 Pump, heating
circuit 1 ("U")
(cont.)
1. Cause
2. Measures
1. Break, room temperature sensor nat-
ural cooling
2. Check the sensor and replace, if
required
1. Short circuit, collector temperature
sensor solar - Vitosolic
2. Check the sensor and replace, if
required
(see Vitosolic installation instructions)
1. Short circuit, return temperature sen-
sor solar - Vitosolic
2. Check the sensor and replace, if
required
(see Vitosolic installation instructions)
1. Break, collector temperature sensor
- Vitosolic
2. Check the sensor and replace, if
required
(see Vitosolic installation instructions)
1. Break, return temperature sensor
solar - Vitosolic
2. Check the sensor and replace, if
required
(see Vitosolic installation instructions)
1. No volume flow in the secondary cir-
cuit
2. Check the pump and replace, if
required
1. Solar circuit without DHW circulation
2. Check the solar circuit pump and
replace, if required
1. Heating circuit pump HK1 without
DHW circulation
2. Check the external heating circuit
pump and replace, if required
Troubleshooting
Access
right
Customer
Customer
Customer
Customer
Customer
Customer
Customer
Customer
125