Viessmann VITOCAL 350-A, Installation And Service Instructions Manual

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144
Message
System characteristics Cause Measures
«
B4 AD converter
Internal fault ADC (ana-
logue digital converter,
reference), ribbon cable
between sensor PCB
and main PCB faulty, or
PCBs faulty Check sensor connec-
tions F1, F5, F10, F15,
F19 and F22 on PCB 3.
Never connect any exter-
nal components. Check
PCB; if required, replace
in the following order:
PCB 3, PCB 2, program-
ming unit.
«
B5 EEPROM
Internal fault, EEPROM Replace coding card.
«
B9 KM BUS solar
Communication error -
KM BUS solar control
unit, or sensor S3 of
Vitosolic faulty ■ Check parameter
"Vitosolic type" .
■ Check connection to
Vitosolic.
■ Check sensor S3 and
replace if required.
Installation and
service instruc-
tions, Vitosolic
«
BA KM BUS Mi/HC
KM BUS communication
error or internal fault in
extension kit for one
heating circuit with mixer
M3 Check extension kit con-
nections and code.
«
BC HC1 R/C KM BUS
Communication error -
KM BUS remote control;
heating circuit without
mixer A1 Check remote control
connections and code;
switch ON remote con-
trol.
«
BD HC2 R/C KM BUS
Communication error -
KM BUS remote control;
heating circuit with mixer
M2 Check remote control
connections and code;
switch ON remote con-
trol.
Troubleshooting
Control unit diagnostics
(cont.)
5414 828 GB