10 Troubleshooting; Contacting Your Service Partner; Reading Off The Fault Codes; Querying The Fault Memory - Vaillant uniTOWER plus Operating Instructions Manual

10 Troubleshooting

10.1

Contacting your service partner

If you contact your service partner, please mention if pos-
sible:
–
The fault code that is displayed (F.xx)
–
The status code (S.xx) that is displayed by the product in
the Live Monitor
10.2

Reading off the fault codes

If a fault develops in the product, the display shows a fault
code F.xx.
Fault codes have priority over all other displays.
If multiple faults occur at the same time, the display shows
the corresponding fault codes for two seconds each in se-
quence.
▶
Eliminate the fault.
▶
To start up the product again, press the reset button
( Operating instructions).
▶
If you are unable to eliminate the fault and the fault re-
curs despite several reset attempts, contact Customer
Service.
10.3

Querying the fault memory

The product has a fault memory. You can use this to query
the last ten faults that occurred in chronological order.
To call up the fault memory, select Menu → Installer level →
List of faults.
The display shows:
–
Number of faults that occurred
–
The fault that is currently selected with fault number F.xx
–
A plain text display explaining the fault.
▶
Use the or button to display the last ten faults that
occurred.
10.4

Resetting the fault memory

▶
Press twice and then Delete and OK to delete the
fault list.
10.5

Displaying Live Monitor (status codes)

Status codes in the display provide information on the pro-
duct's current operating mode. These can be called up via
the Live Monitor menu.
10.6

Using the function menu

You can use the function menu to actuate and test individual
components of the product during the fault diagnostics.
(→ Section 10.7)
42
10.7

Carrying out the actuator test

Menu → Installer level → Test menu → Sensor/actuator
test
You can check that the components of the heating installa-
tion are functioning correctly using the sensor/actuator test.
You can actuate more than one actuator at a time.
If you do not select anything to change, you can have the
current control values for the actuators and the sensor val-
ues displayed.
You can find a list of the sensor characteristic values in the
appendix.
Characteristic values for the internal temperature sensors,
hydraulic circuit (→ Appendix M)
Characteristic values for the VRC DCF outdoor temperature
sensor (→ Appendix O)
10.8

Safety cut-out

The product has a safety cut-out.
If the safety cut-out has tripped, the cause must be elimin-
ated and the safety cut-out replaced.
▶
See the "Fault codes" table in the appendix.
Fault codes (→ Appendix J)
▶
Check the back-up heater for damage due to overheat-
ing.
▶
Check that the power supply for the power supply PCB is
working properly.
▶
Check the cabling for the power supply PCB.
▶
Check the cabling for the electric back-up heater.
▶
Check that all temperature sensors are working properly.
▶
Check that all other sensors are working properly.
▶
Check the pressure in the heating circuit.
▶
Check that the heating circuit pump is working properly.
▶
Check whether there is air in the heating circuit.
10.8.1 Replace the safety cut-out
C
B
1. Disconnect the product from the power grid and protect
it against being switched back on.
2. Remove the front casing.
3. Remove the cover from the power supply PCB.
(→ Section 6.5)
4. Remove the connection cable from terminal block
X302.
Installation and maintenance instructions 0020291525_04
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