24
A9 Heat pump
Compressor stops.
Cause
Measure
■
Heat pump faulty
■
Safety high pressure switch has responded.
■
One
of the following results has occurred 9 times.
–
High pressure limit exceeded
–
Low pressure limit undershot
–
The refrigerant circuit controller has shut down the
compressor.
Note
The event counter is reset as soon as the compressor
has been operational
continuously once
for a set
time.
■
Safety chain is interrupted for more than 24 h.
■
Refrigerant circuit fault (
"C9 Refrigerant circ
(SHD)"
)
■
Temperature sensors in primary/secondary circuit
faulty
■
Calling up further heat pump messages:
"Message
history"
■
Observe messages from the refrigerant circuit con-
troller:
"Diagnosis"
"Refrigerant circuit"
"Mes-
sage history"
■
Check flow rates.
■
Check motor currents/motor overload relay.
■
Check safety high pressure switch.
Note
After removing the fault, switch the appliance first off
and then on again.
B0 Device recognition
Heat pump does not start.
Cause
Measure
Error in recognising appliance version, incorrect coding
card or PCBs faulty.
■
Check coding card (see "Controller and sensor
PCB"); replace if necessary.
■
Check PCBs and replace if necessary.
Note
After removing the fault, switch appliance off and on
again.
B4 AD converter
Heat pump does not start.
Cause
Measure
Internal fault ADC (analogue digital converter, refer-
ence), ribbon cable between sensor PCB and main
PCB faulty, or PCBs faulty.
Check PCB; if necessary, replace in the following order:
Controller and sensor PCB, main PCB.
Note
After removing the fault, switch appliance off and on
again.
B5 Hardware
Heat pump does not start.
Addition-
al code
Cause
Measure
DF
Flash memory fault, main PCB.
Replace main PCB (see "main PCB").
Troubleshooting
Message overview
(cont.)
5800 917 GB
Maintenance
