Vaillant flexoTHERM exclusive VWF 57/4 230V Installation And Maintenance Instructions Manual Download Page 45

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0020213395_04 Installation and maintenance instructions

Maintenance messages

Code

Meaning

Cause

Remedy

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.33

Only with
the heat
source:
Air

Fan unit: Cleaning required

–

Air inlet or air outlet of the air-to-
brine heat exchanger contaminated

–

Heat transfer from the air to the brine
heat transfer medium is too low

–

Brine pipes inverted

–

Air in the environment circuit

–

Defective de-icer

–

Fan noise reduction mode activated

–

The fan unit is de-iced more fre-
quently than is required. The effi-
ciency of the heat pump is reduced.
Loosen and clean any dirt from the
fan unit (air-to-brine heat exchanger)

–

Check that the connections are
correctly assigned to the brine lines

–

Purge the environment circuit

–

Check de-icer (sensor/actuator test?)

–

Reduce noise reduction mode

–

Completely deactivate fan noise
reduction mode

M.34

Environment circuit: Pressure low

–

Pressure loss in the environment
circuit due to leakages or air pockets

–

Environment circuit pressure sensor
defective

–

Check the environment circuit for
leaks, top up with medium (brine-to-
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.49

Only with
the heat
source:
Air

Environment circuit: Brine lines
inverted

–

Check that the connections are
correctly assigned to the brine lines

Fault codes

Note

Since the code table is used for various products, some codes may not be visible for the product in question.

In the event of faults which are caused by components in the refrigerant circuit, inform customer service.

Code

Meaning

Cause

Remedy

F.070

Fault: Invalid Device Specific
Number

–

Replacing the control PCB and
display PCB

–

Setting the correct Device Specific
Number

F.086

Building circuit: Lockout co. S20
open

–

Contact S20 on heat pump main
PCB (HMU) open

–

Incorrect setting of the limit thermo-
stat

–

Flow temperature sensor (heat
pump, gas-fired boiler, system
sensor) measures values that
deviate downwards

–

Adjust the maximum flow temperat-
ure for the direct heating circuit via
the system control (observe the up-
per switch-off threshold for the boil-
ers)

–

Adjust the set value for the limit ther-
mostat

–

Check the sensor values

F.514

Sensor fault: Compr. inlet temp.

–

Sensor not connected or sensor in-
put has short-circuited

–

Check the sensor, and replace if
necessary

–

Replace the cable harness