Vaillant ecoTEC plus VUI Series Installation And Maintenance Instructions Manual page 74

Code/meaning
F.013
The cylinder temperature
sensor has short-circuited.
F.020
The safety cut-out (SCO) inter-
rupts the gas valve control. The
gas valve was closed because
the temperature of the flow or
return temperature sensor has
exceeded the maximum limit.
F.022
No/insufficient water in the
product or the water pressure is
too low.
F.023
The temperature spread
between the flow/return is too
great.
F.024
The temperature increases too
quickly.
74
Possible cause
Fault in the electrical connection
for the cylinder temperature
sensor
Cylinder temperature sensor
defective
Insufficient/no water in the
product.
Fault in the electrical connection
for the flow temperature sensor
Fault in the electrical connec-
tion for the return temperature
sensor
Flow temperature sensor de-
fective
Return temperature sensor de-
fective
The pump is defective.
3-port diverter valve defective or
blocked
Water pressure sensor defect-
ive
Volume flow sensor defective
Black discharge via the ignition
cable, ignition plug or ignition
electrode
Insufficient/no water in the
product.
Fault in the electrical connection
for the water pressure sensor
Cable for the pump/for the wa-
ter pressure sensor is loose/not
connected/defective
Water pressure sensor defect-
ive
Pump operation interrupted
Solenoid valve for the automatic
filling device defective
Internal expansion vessel de-
fective
Air in the product
Fault in the electrical connection
for the flow temperature sensor
Fault in the electrical connec-
tion for the return temperature
sensor
Flow temperature sensor de-
fective
Return temperature sensor de-
fective
Pump blocked
Pump runs with insufficient out-
put
3-port diverter valve defective or
blocked
Internal expansion vessel de-
fective
Air in the product
System pressure too low
Fault in the electrical connection
for the flow temperature sensor
Measure
▶
Check and, if required, replace the wiring harness between the
PCB and sensor, including all plug connections.
▶
Check and, if required, replace the cylinder temperature
sensor.
1. Fill the heating installation.
2. Check the product and the system for leakages.
▶
Check and, if required, replace the wiring harness between the
PCB and sensor, including all plug connections.
▶
Check and, if required, replace the wiring harness between the
PCB and sensor, including all plug connections.
▶
Check and, if required, replace the flow temperature sensor.
▶
Check and, if required, replace the return temperature sensor.
▶
Check and, if required, replace the pump.
▶
Check and, if required, replace the 3-port diverter valve.
▶
Check and, if required, replace the water pressure sensor.
▶
Check and, if required, replace the volume flow sensor.
▶
Check the ignition cable, ignition plug and ignition electrode.
1. Fill the heating installation.
2. Check the product and the system for leakages.
▶
Check and, if required, replace the wiring harness between the
PCB and sensor, including all plug connections.
▶
Check the cable for the pump/for the water pressure sensor.
▶
Check and, if required, replace the water pressure sensor.
▶
Check and, if required, replace the cable to the pump/to the
water pressure sensor.
▶
Check the automatic filling device and replace it, if necessary.
▶
Check the internal expansion vessel and replace it, if neces-
sary.
▶
Purge the heating installation.
▶
Check and, if required, replace the wiring harness between the
PCB and sensor, including all plug connections.
▶
Check and, if required, replace the wiring harness between the
PCB and sensor, including all plug connections.
▶
Check and, if required, replace the flow temperature sensor.
▶
Check and, if required, replace the return temperature sensor.
▶
Check that the pump is working correctly.
▶
Check that the pump is working correctly.
▶
Check and, if required, replace the 3-port diverter valve.
▶
Check the internal expansion vessel and replace it, if neces-
sary.
▶
Purge the heating installation.
▶
Check the system pressure.
▶
Check and, if required, replace the wiring harness between the
PCB and sensor, including all plug connections.
Installation and maintenance instructions 0020308121_04