Appendix
Statuscode
S.305 Condensation temperat-
ure too low
S.306 Evaporation temperat-
ure too high
S.308 Condensation temperat-
ure too high
S.312 Building circuit: Return
temperature too low
S.314 Building circuit: Return
temperature too high
S.351 Immersion heater: Flow
temp. too high
S.516 De-icing mode active
S.575 Frequency converter:
Internal fault
S.581 Connection fault: Fre-
quency converter not recog-
nised
S.590 Fault: 4-port valve posi-
tion not correct
G
Maintenance messages
Code
Meaning
M.23
Status external current anode
M.32
Building circuit: Pressure low
M.200
Building circuit 2: Low pressure
M.201
Sensor fault: Cylinder temperature
M.202
Sensor fault: System temperature
M.203
Connection fault: Disp. not recog-
nised
52
Meaning
The operating characteristics have been exited. The heat pump is restarted.
The operating characteristics have been exited. The heat pump is restarted.
The operating characteristics have been exited. The heat pump is restarted.
Return temperature in the building circuit too low for compressor to start. Heating: Return temperature
< 5 °C. Cooling: Return temperature < 10 °C. Heating: Check that the 4-port diverter valve works cor-
rectly.
Return temperature in the building circuit too high for the compressor to start. Heating: Return tem-
perature > 56 °C. Cooling: Return temperature > 35 °C. Cooling: Check that the 4-port diverter valve
works correctly. Check the sensors.
The flow temperature at the immersion heater is too high. Flow temperature > 75 °C. The heat pump
is switched off.
The heat pump de-ices the outdoor unit's heat exchanger. The heating mode is interrupted. The max-
imum de-icing time is 16 minutes.
An internal electronics fault is present on the outdoor unit's inverter PCB. If this occurs three times,
fault message F.752 appears.
Missing communication between the frequency converter and the outdoor unit's PCB. After this oc-
curs three times, fault message F.753 appears.
The 4-port diverter valve does not move fully to the heating or cooling position.
Cause
–
External current anode not recog-
nised
–
Pressure loss in the building circuit
due to leakages or air pockets
–
Building circuit pressure sensor is
defective
–
Pressure loss in the building circuit
due to leakages or air pockets
–
Building circuit pressure sensor is
defective
–
Cylinder temperature sensor defect-
ive
–
System temperature sensor defective
–
Display defective
–
Display not connected
Installation and maintenance instructions Hydraulic station 0020257319_02
Remedy
–
If required, check for a cable break
–
Check the building circuit for leaks,
top up with heating water and purge
–
Check the plug contact on the PCB
and on the cable harness; check
that the pressure sensor is working
correctly and, if required, replace the
pressure sensor
–
Check the building circuit for leaks,
top up with heating water and purge
–
Check the plug contact on the PCB
and on the cable harness; check
that the pressure sensor is working
correctly and, if required, replace the
pressure sensor
–
Check the plug contact on the PCB
and on the cable harness; check that
the sensor is working correctly and,
if required, replace the sensor
–
Check the plug contact on the PCB
and on the cable harness; check that
the sensor is working correctly and,
if required, replace the sensor
–
Check the quality of the plug contact
on the PCB and on the cable har-
ness
–
Replace the display, if required