Viessmann VITOCAL 300-G Installation And Service Instructions Manual page 136

Troubleshooting
Messages
(cont.)
Message
System characteristics Cause
9A Collector sensor
9B Return sensor solar
A6 Secondary pump
A7 Solar circuit
A8 Pump heating circuit 1
136
Lead break, Vitosolic col-
lector temperature sen-
sor
Lead break, Vitosolic
return temperature sen-
sor
No flow in secondary cir-
cuit (secondary circuit
pump stopped)
No flow in solar circuit
(solar circuit pump stop-
ped)
No flow in heating circuit
A1 (circuit pump stop-
ped)
Measures
Check sensor and replace
if required (see Vitosolic
installation and service
instructions).
Check sensor and replace
if required (see Vitosolic
installation and service
instructions).
Check voltage at connec-
tion 211. 2 and check sec-
ondary pump mechani-
cally; replace if required.
Check voltage at connec-
tion between the solar cir-
cuit pump and Vitosolic
and check solar circuit
pump; replace if required
(see Vitosolic installation
and service instructions).
Test voltage at connection
212.2 and check pump
mechanically; replace if
required.