Viessmann VITOCAL 151-A Installation And Service Instructions Manual page 113

Fault messages
(cont.)
Message code System characteristics
F.1012 Refrigerant circuit off
F.1045 External heat generator not
ready for operation
F.1049 External heat generator not
ready for operation
F.1050 Uncontrolled operation of the
external heat generator
F.1051 Uncontrolled operation of the
external heat generator
F.1054 External heat generator not
ready for operation
F.1056 Heat pump off
Warning messages
Note
The possible warning messages vary according to the
system equipment. Therefore, not all warning mes-
sages will come up for every system.
Message code System characteristics
A.2 Frost protection enabled
■
Heat demand, heat pump
■
running.
DHW circulation pump ena-
■
bled
A.11 Central heating/cooling only
for some rooms
A.12 Incorrect time
Cause
Fault, low pressure sensor To check the sensor, measure the
Fault on external heat
generator
3/2-way mixing valve not
switching.
Short circuit, boiler water
temperature sensor, exter-
nal heat generator
Lead break, boiler water
temperature sensor, exter-
nal heat generator
Max. temperature of exter-
nal heat generator excee-
ded
Inverter relay faulty
Cause
Outside temperature has
undershot the specified
frost protection limit.
System pressure too low
Battery in HPMU electron-
ics module flat.
Troubleshooting
Measures
voltage at the sensor or at connec-
tion X14.4 to X14.6 of the VCMU
refrigerant circuit controller (0 to
5 V). Replace sensor if required.
Check the fault message on the
control unit of the external heat
generator. Remedy the fault.
Installation and service in-
structions for external heat
generator and associated
control unit
Check the 3/2-way mixing valve.
Replace if required.
Check resistance value
(NTC 10 k ) at connection TS2 of
Ω
the HIO electronics module. Re-
place sensor if necessary.
Check resistance value
(NTC 10 k ) at connection TS2 of
Ω
the HIO electronics module. Re-
place sensor if necessary.
Check the cause of exceeding the
max. temperature at the external
heat generator. Remedy any fault.
Installation and service in-
structions for external heat
generator and associated
control unit
Replace inverter.
Measures
No action required
Top up with water.
Replace CR2032 battery in
■
HPMU electronics module.
Set the time on the programming
■
unit: See operating instructions.
113