Vaillant VWZ AI User Manual

Appendix
30 Installation instructions Heat pump control interface module 0020291573_00
Code Meaning Cause
Remedy
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
F Fault codes
Code Meaning Cause
Remedy
F.022 Water pressure too low – Pressure loss in the building circuit
due to leakages or air pockets
– Building circuit pressure sensor
defective
– Check the building circuit for leaks
– Top up with water, purge
– Check the quality of the plug contact
on the PCB and on the cable har-
ness
– Check that the pressure sensor is
working correctly
– Replace the pressure sensor
F.042 Fault: Coding resistor – Coding resistor damaged or not set – Check that the coding resistor is
positioned correctly and, if required,
replace it.
F.073 Sensor fault: Build. circ. pressure – The sensor is not connected or the
sensor input has short-circuited
– Check and, if required, replace the
sensor
– Replace the cable harness
F.094 Fault: Vortex – Volume flow sensor not connected or
sensor input has short-circuited
– Check and, if required, replace the
sensor
– Replace the cable harness
F.103 Fault: Spare part ident. – Incorrect control PCB installed on
the outdoor unit
– Installing the correct PCB
F.514 Sensor fault: Compr. inlet temp.
– The sensor is not connected or the
sensor input has short-circuited
– Check and, if required, replace the
sensor
– Replace the cable harness
F.517 Sensor fault: Compr. outlet temp. – The sensor is not connected or the
sensor input has short-circuited
– Check and, if required, replace the
sensor
– Replace the cable harness
F.519 Sensor fault: Building circuit re-
turn temp.
– The sensor is not connected or the
sensor input has short-circuited
– Check and, if required, replace the
sensor
– Replace the cable harness
F.520 Sensor fault: Building circuit flow
temp.
– The sensor is not connected or the
sensor input has short-circuited
– Check and, if required, replace the
sensor
– Replace the cable harness
F.526 Sensor fault: EEV outlet temp. – The sensor is not connected or the
sensor input has short-circuited
– Check and, if required, replace the
sensor
– Replace the cable harness
F.546 Sensor fault: High pressure – The sensor is not connected or the
sensor input has short-circuited
– Check the sensor (e.g. using an in-
stallation aid), and replace if neces-
sary
– Replace the cable harness
F.582 Fault: EEV – EEV is not connected correctly or
there is a cable break to the coil
– Check the plug connections and, if
required, replace the coil from the
EEV
F.585 Sensor fault: Capac. outlet temp. – The sensor is not connected or the
sensor input has short-circuited
– Check and, if required, replace the
sensor
– Replace the cable harness
F.703 Sensor fault: Low pressure – The sensor is not connected or the
sensor input has short-circuited
– Checking the sensor (e.g. using an
installation aid), and replacing it if
necessary
– Replace the cable harness
F.718 Fan unit 1: Fan blocked – There is no confirmation signal stat-
ing that the fan is rotating
– Check the air route and, if required,
remove any blockages

Vaillant VWZ AI Specifications

General

Brand	Vaillant
Model	VWZ AI
Category	Control Unit
Language	English