F.044
The ionisation signal for the control electrode is too low. The drift adaptation has failed.
Vaillant ecoTEC Plus Combi
Possible cause
Fault in the flue gas route caused by recirculation or flue gas blockage
Measure
Check the entire flue gas route.
Possible cause
Air intake pipe blocked
Measure
Check and, if required, replace the air intake pipe.
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.
Possible cause
Gas flow pressure too low
Measure
Check the gas flow pressure and the external gas pressure switch.
Possible cause
Incorrect gas type set
Measure
Check the gas type and the gas type setting under D.156 and D.157.
Possible cause
Interruption in the wiring harness
Measure
Check the wiring harness including all plug connections and, if required, replace it.
Possible cause
Burner defective
Measure
Check and, if required, replace the burner.
Possible cause
Gas valve assembly defective/incorrect spare part gas valve assembly
Measure
Check and, if required, replace the gas valve assembly.
Possible cause
Gas valve assembly offset incorrectly stored in D.052 and, if applicable, D.182
Measure
Check the offset setting for the gas valve assembly.
Possible cause
Control electrode defective
Measure
Check and, if required, replace the control electrode.
Possible cause
Gas valve defective
Measure
Replace the gas valve.
Possible cause
PCB defective
Measure
Replace the PCB.