Vaillant ecoTEC plus VUI Series User Manual

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

Vaillant ecoTEC plus VUI Series Specifications

General

Brand	Vaillant
Model	ecoTEC plus VUI Series
Category	Boiler
Language	English