Operating instructions

57
Message
System characteristics Cause Measures
■ Check power supply,
power cable and plug to
the instantaneous heat-
ing water heater
■ Test instantaneous
heating water heater
control signal at con-
nections 211.3; check
high limit safety cut-out
and reset if required;
check instantaneous
heating water heater.
Installation
instructions,
instantaneous
heating water
heater
B4 A-D 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 the con-
troller and sensor circuit
board.
B5 EEPROM
Internal error EEPROM Replace coding card.
B9 KM BUS solar
Communication error -
KM BUS solar control
unit, or sensor S3 of
Vitosolic faulty
■ Check parameter
"Solar collector".
■ Check connection to
Vitosolic.
■ Check sensor S3 and
replace, if required (see
Vitosolic installation
and service instruc-
tions).
Troubleshooting
Messages
(cont.)
5441 603 GB
Service