Vaillant flexoTHERM exclusive VWF 117/4 Installation And Maintenance Instructions Manual page 52

Appendix
Code Meaning
F.782 Connection error: Fan unit 2
F.783 Connection error: Terminal block
(TMB)
F.784 Connection error: ICL
F.785 Fan unit 2: Fan blocked
F.786 Fan unit 2: Safety cut-out open
F.787 Environment circuit: Pressure
mon. open
F.788 Building circuit: Pump fault
F.789 Sensor fault: Fan unit 2 fan inlet
temp.
F.790 Sensor fault: Fan unit 2 brine flow
temp.
F.792 Sensor fault: VI inlet temp.
F.793 Sensor fault: EEV-VI outlet temp.
52
Cause
–
No electrical connection
No eBUS connection
Cable not connected or connected incor-
rectly
Cable not connected or connected incor-
rectly
–
There is no confirmation signal stat-
ing that the fan is rotating
–
The safety cut-out on the de-icer is
open due to insufficient volume flow
and/or brine temperatures above
65 °C
–
Operating the de-icer outside of the
permitted area of application
–
De-icer operation when the brine
circuit is not filled
–
During de-icer operation at brine
temperatures above 115 °C, the fuse
of the safety cut-out is tripped and
the fuse must be replaced.
–
Pressure loss in the environment
circuit due to leaks or air pockets
–
Environment circuit pressure monitor
defective
–
The electronics system of the high-
efficiency pump has detected a
fault (e. g. dry running, blockage,
overvoltage, undervoltage) and
switched the pump off as a securing
measure.
–
Sensor not connected or sensor
input has short-circuited
–
Sensor not connected or sensor
input has short-circuited
–
Sensor not connected or sensor
input has short-circuited
–
Sensor not connected or sensor
input has short-circuited
Installation and maintenance instructions flexoTHERM exclusive 0020213394_01
Remedy
–
Check the electrical connection to
fan unit 2 (check the line connection;
contact fault? Has the circuit breaker
tripped in the connection box?)
–
Check the eBUS connection to fan
unit 2
–
Check the address switch position
on the PCB of fan unit 2. Required
switch position: 2
Check the connection line between the
mains connection PCB and the controller
PCB
Check the connection line between the
mains connection PCB and the in-rush
current limiter PCB
–
Check the air route and, if required,
remove any blockages
–
Check and, if required, replace the
F1 fuse on the PCB in the fan unit
(OMU)
–
Checking for circulation in the envir-
onment circuit pump
–
If required, open the stop cock. The
safety cut-out is automatically reset
as soon as the temperature at the
fuse falls below 30 °C again. If the
safety cut-out is still open at a de-
icer temperature below 65 °C (or
30 °C), temperatures above 115 °C
were reached and the fuse tripped.
–
Check and, if required, replace the
F1 fuse of the air/brine collector
–
Replace the safety cut-out
–
Check the environment circuit for
leaks
–
Top up the medium (brine/water),
purge
–
Check the screwed contact on the
PCB
–
Check that the pressure monitor
works correctly
–
Replace the pressure monitor
–
Switch the heat pump off for at least
30 seconds (no current)
–
Check the quality of the plug contact
on the PCB
–
Check that the pump functions cor-
rectly
–
Purging the building circuit
–
Check the sensor in the fan unit, and
replace if necessary
–
Replace the cable harness in the fan
unit
–
Check the sensor in the fan unit, and
replace if necessary
–
Replace the cable harness in the fan
unit
–
Check the sensor, and replace if
necessary
–
Replace the cable harness
–
Check the sensor, and replace if
necessary
–
Replace the cable harness