F.029
The ignition following a flame loss during operation was unsuccessful.
Vaillant ecoTEC Plus Combi
Possible cause
The gas supply is interrupted
Measure
Check the gas supply.
Possible cause
Fault in the flue gas route caused by recirculation or flue gas blockage
Measure
Check the entire flue gas route.
Possible cause
Earthing defective
Measure
Check the product's earthing.
Possible cause
Air intake pipe blocked
Measure
Check and, if required, replace the air intake pipe.
Possible cause
Ignition failed
Measure
1. Check the ignition using check programme P.021.
2. Product starts: Ignition electrode, ignition transformer, gas valve assembly and fan are working, gas is flowing and the gas volume is correct, no blockage or recirculation detected.
3. Product does not start and displays a fault code again: Carry out the next check for the cause.
Possible cause
Ignition misfire
Measure
Check that the ignition transformer works correctly.
Possible cause
Control electrode comes into contact with the burner
Measure
1. Check the clearance between the control electrode and the burner.
2. Check and, if required, replace the control electrode.
Possible cause
Burner defective
Measure
Check and, if required, replace the burner.
Possible cause
Interruption in the wiring harness
Measure
Check the wiring harness including all plug connections and, if required, replace it.
Possible cause
Ignition electrode defective
Measure
Check and, if required, replace the ignition electrode.
Possible cause
Gas valve assembly defective/incorrect spare part gas valve assembly
Measure
Check and, if required, replace the gas valve assembly.
Possible cause
Condensate in the combustion chamber due to a blocked condensate discharge
Measure
1. Check and, if required, clean the condensate discharge pipe including the siphon.
2. Check that the condensate discharge has been installed correctly.
3. Check the combustion chamber (electrodes, insulating mats, burner).
4. If required, replace the insulating mats in the combustion chamber.
Possible cause
Condensate pump (if fitted) defective
Measure
Check and clean the condensate pump. Replace the condensate pump, if required.