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