Viessmann VITOCAL 300-A Installation And Service Instructions Manual page 123

Control unit diagnostics
Message
UB0 Device recognition
UB1 KM BUS EEV
UB4 A-D converter
UB5 EEPROM
UB9 KM BUS solar
UBA KM BUS Mi/HC
UBC HC1 R/C KM BUS
UBD HC2 R/C KM BUS
(cont.)
Cause
Error in recognising ap-
pliance version, incor-
rect coding card or PCB
faulty.
Communication error
EEV module (EEV: elec-
tronic expansion valve)
Internal fault ADC (ana-
log digital converter, re-
ference), ribbon cable
between sensor PCB
and main PCB faulty, or
PCBs faulty
Internal error EEPROM
Communication error
KM BUS solar control
unit, or sensor S3 of the
Vitosolic faulty
Communication error
KM BUS or internal fault
extension kit for one
heating circuit with mixer
M3
Communication error
KM BUS remote control;
heating circuit without
mixer A1
Communication error
KM BUS remote control;
heating circuit with mixer
M2
Troubleshooting
Measures
&
Check sensor input F11.
Never connect any
external components
(see page 166).
&
Check coding card and
replace if required
&
Check PCBs and replace
if required
Check leads/cables, PCB
refrigerant circuit control-
ler: Check the power sup-
ply and replace the PCB if
required
Check sensor connections
F1, F5, F10, F15, F19 and
F22. Never connect any
external components.
Check PCBs and replace if
required.
Replace coding card
&
Check parameter
"Vitosolic type" (see
page 141)
&
Check connection to the
Vitosolic
&
Check sensor S3 and
replace if required
See Vitosolic installation
and service instructions
Check the extension kit
connections and coding
Check remote control con-
nections and coding (see
page 53); switch ON re-
mote control
Check remote control con-
nections and coding (see
page 53); switch ON re-
mote control
123