Appendix
36
Installation instructions aroTHERM 0020147164_09
Code
Meaning
Cause
F.750
Connection fault: Compressor
–
Cable insulation defective
–
Connection broken
F.751
Compressor: Overcurrent fault
–
The product's power supply is too low
–
The fin-type heat exchanger or heat exchanger is dirty
F.752
Fault: Frequency converter
–
The parameter
Max. duration power supply cut-off
has been
poorly set (see "Heat pump setting parameters" in the appendix).
–
Inverter box damaged
–
The cooler inverter box is blocked
–
Faulty power supply
F.753
Connection fault: Frequency converter not recog-
nised
–
The parameter
Max. duration power supply cut-off
has been
incorrectly set (see "Heat pump setting parameters" in the ap-
pendix).
–
The connection between the main PCB and the inverter box is
damaged or broken
–
Inverter box is not switched on
F.754
Fault: Fan unit
–
The connection between the main PCB and the fan PCB is dam-
aged or broken
–
The fan PCB is defective
F.755
Fault: 4-port diverter valve position incorrect
Mechanical or electrical problem. Move the 4-port diverter valve
away from the control. When moving it, check that the coil voltage
is correct.
Check the cable harness and the connections. Check the temperat-
ure sensor for the finned-tube heat exchanger for plausibility (to do
this, use a surface-mounted thermometer and the display in the actu-
ator/sensor test T.0.28 test menu)
F.774
Sensor fault: Air inlet temperature
The temperature sensor is defective or incorrectly connected to the
main PCB.
F.1288
Fault: SP1 cylinder temperature sensor
Sensor is defective or has not been correctly connected to the
VWZ AI heat pump control interface module.
Connection fault: Accessory modules
Fault in the VWZ AI heat pump control interface module (the connec-
tion between the display and the main PCB is defective)
Connection fault: Heat pump
The eBUS connection between the heat pump and the VWZ AI heat
pump control interface module is defective
1) Sensor on the evaporator
2) Sensor on the condenser
For further technical information, please call 0330 100 3540.
