Vaillant ecoTEC plus VUI Series Installation And Maintenance Instructions Manual page 82

Code/meaning
F.096
The gas valve stepper motor
has reached the maximum per-
missible step number.
F.097
The self-test of the main PCB
has failed.
F.105
If the gas valve or the PCB and
the unit interface are replaced,
the gas valve offset must be set
in accordance with the current
gas valve.
F.194
The power supply unit for the
PCB is defective.
F.195
The unit has detected signific-
ant undervoltage in the power
supply.
F.196
The unit has detected signific-
ant overvoltage in the power
supply.
F.317
The signal for the volume flow
sensor in the domestic hot wa-
ter circuit is implausible.
F.318
The 3-port motorised valve
does not move.
F.320
The heating pump is blocked.
The unlocking function was not
successful.
F.321
The pump electronics are de-
fective.
F.322
The heating pump has over-
heated. The temperature could
not be lowered by the limp
home mode.
F.323
The heating pump is dry run-
ning.
F.324
The electrical connection to the
pump has been interrupted.
F.325
The heating pump has a fault.
82
Possible cause
Air-mass flow sensor dirty or
defective (only in conjunction
with the conversion set compris-
ing the air intake pipe with in-
tegrated non-return valve and
air-mass flow sensor)
PCB self-test failed (PCB de-
fective)
Gas valve assembly offset in-
correctly stored in D.052 und
ggf. D.182
Fault in the electrical connection
for the gas valve assembly
Power supply unit for the PCB
is defective
Undervoltage in the power sup-
ply
Pump defective
Fault in the electrical connection
for the pump
Overvoltage in the power supply
Pump defective
Fault in the electrical connection
for the pump
Fault in the electrical connection
for the volume flow sensor in
the domestic hot water circuit
Volume flow sensor in the do-
mestic hot water circuit defect-
ive
Fault in the electrical connection
for the 3-port diverter valve
3-port diverter valve defective or
blocked
Dirt or foreign bodies in the
pump
The pump is defective.
The pump temporarily reports
excessive temperatures in the
electronics
Air in the product
Pump has been dry-running
The cable to the pump is de-
fective
The pump is defective.
Pump blocked
The pump is defective.
Measure
1. Check the air-mass flow sensor for dirt.
2. If required, replace the entire air intake pipe.
▶
Replace the PCB.
▶
Check the offset setting for the gas valve assembly.
▶
Check the wiring harness between the PCB and gas valve
assembly, incl. all plug connections.
▶
Replace the PCB.
▶
Check the mains voltage.
▶
If the mains voltage is not correct, contact the energy supply
company.
▶
If the mains voltage is correct, replace the pump (voltage
measurement via pump electronics).
▶
Check the wiring harness between the PCB and pump, includ-
ing all plug connections.
▶
If the mains voltage is not correct, contact the energy supply
company.
▶
If the mains voltage is correct, replace the pump (voltage
measurement via pump electronics).
▶
Check the wiring harness between the PCB and pump, includ-
ing all plug connections.
▶
Check the wiring harness between the PCB and volume flow
sensor, including all plug connections.
▶
Replace the volume flow sensor in the domestic hot water cir-
cuit.
▶
Check the wiring harness between the PCB and 3-port diverter
valve, including all plug connections.
▶
Check and, if required, replace the 3-port diverter valve.
▶
Clean the pump and, if required, replace the pump.
▶
Check and, if required, replace the pump.
▶
Check the pump and, if required, replace the pump.
▶
Purge the heating installation.
▶
Replace the pump.
▶
Check the cable for the 230 V power supply to the pump and,
if required, replace the cable for the 230 V power supply.
▶
Check and, if required, replace the pump.
▶
Check that the pump is working correctly.
▶
Check and, if required, replace the pump.
Installation and maintenance instructions 0020308121_04