Viessmann VITOCAL 300-G Installation And Service Instructions Manual page 135

Messages
(cont.)
Message
System characteristics Cause
78 Room sensor HC1
■ No frost protection
mode via room temper-
ature sensor
■ No room temperature
hook-up
■ No room temperature
control
79 Room sensor HC2
■ No frost protection
mode via room temper-
ature sensor
■ No room temperature
hook-up
■ No room temperature
control
7A Room sensor HC3
■ No frost protection
mode via room temper-
ature sensor
■ No room temperature
hook-up
■ No room temperature
control
7B Room sensor SKK
92 Collector sensor
93 Return sensor solar
Lead break, room tem-
perature sensor heating
circuit A1
Lead break, room tem-
perature sensor heating
circuit M2
Lead break, room tem-
perature sensor heating
circuit M3
Lead break, room tem-
perature sensor, cooling
circuit
Short circuit, Vitosolic
collector temperature
sensor
Short circuit, Vitosolic
return temperature sen-
sor
Troubleshooting
Measures
Check remote control
sensor and replace if
required (see Vitotrol
service instructions).
Check remote control
sensor and replace if
required (see Vitotrol
service instructions).
Check remote control
sensor and replace if
required (see Vitotrol
service instructions).
Check resistance (type Ni
500) at plug-in connection
F16; replace sensor if
required.
Check sensor and replace
if required (see Vitosolic
installation and service
instructions).
Check sensor and replace
if required (see Vitosolic
installation and service
instructions).
135