Vaillant ecoTEC plus VUI Series User Manual

76 Installation and maintenance instructions 0020308121_04
Code/meaning Possible cause Measure
F.028
The flame signal was not detec-
ted during the ignition phase.
Fault in the flue gas route
caused by recirculation or flue
gas blockage
▶ Check the entire flue gas route.
Ignition transformer not connec-
ted
▶ Check the plug and the plug connection.
Defective ignition transformer ▶ Check that the ignition transformer is working correctly and, if
required, replace it.
PCB defective ▶ Replace the PCB.
Condensate in the combustion
chamber due to a blocked con-
densate discharge
1. Check and, if required, clean the condensate discharge pipe
including the siphon.
2. Check the combustion chamber (electrodes, insulating mats,
burner).
3. If required, replace the insulating mats in the combustion
chamber.
F.029
The ignition following a flame
loss during operation was un-
successful.
The gas supply is interrupted ▶ Check the gas supply.
Fault in the flue gas route
caused by recirculation or flue
gas blockage
▶ Check the entire flue gas route.
Earthing defective ▶ Check the product's earthing.
Air intake pipe blocked ▶ Check and, if required, replace the air intake pipe.
Ignition misfire ▶ Check that the ignition transformer works correctly.
Condensate pump (if fitted)
defective
▶ Check and clean the condensate pump. Replace the condens-
ate pump, if required.
Control electrode comes into
contact with the burner
1. Check the clearance between the control electrode and the
burner.
2. Check and, if required, replace the control electrode.
Burner defective ▶ Check and, if required, replace the burner.
Interruption in the wiring har-
ness
▶ Check the wiring harness including all plug connections and, if
required, replace it.
Ignition electrode defective ▶ Check and, if required, replace the ignition electrode.
Gas valve assembly defect-
ive/incorrect spare part gas
valve assembly
▶ Check and, if required, replace the gas valve assembly.
Condensate in the combustion
chamber due to a blocked con-
densate discharge
1. Check and, if required, clean the condensate discharge pipe
including the siphon.
2. Check the combustion chamber (electrodes, insulating mats,
burner).
3. If required, replace the insulating mats in the combustion
chamber.
F.032
The fan speed is outside of the
tolerance.
Fault in the electrical connection
for the fan
▶ Check the wiring harness between the PCB and fan, including
all plug connections.
Fan blocked ▶ Check that the fan works correctly.
Fan defective ▶ Check and, if required, replace the fan.
Fault in the flue gas route
caused by recirculation or flue
gas blockage
▶ Check the entire flue gas route.
PCB defective ▶ Replace the PCB.
F.035
The air/flue pipe is blocked.
Air/flue pipe blocked during
initial start-up
▶ Check the entire flue gas route and deactivate D.145.
Air intake pipe blocked ▶ Check and, if required, replace the air intake pipe.
Gas flow pressure too low ▶ Check the gas flow pressure and the external gas pressure
switch.
Fault in the flue gas route
caused by recirculation or flue
gas blockage
▶ Check the entire flue gas route.
Condensate in the combustion
chamber due to a blocked con-
densate discharge
1. Check and, if required, clean the condensate discharge pipe
including the siphon.
2. Check the combustion chamber (electrodes, insulating mats,
burner).
3. If required, replace the insulating mats in the combustion
chamber.

Vaillant ecoTEC plus VUI Series Specifications

General

Brand	Vaillant
Model	ecoTEC plus VUI Series
Category	Boiler
Language	English