F.057
The combustion regulation has failed and the associated limp home mode has failed.
Vaillant ecoTEC Plus Combi
Possible cause
Limp home mode failed
Measure
Check the limp home mode and fault history, and carry out the required measures.
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
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
Interruption in the wiring harness
Measure
Check the wiring harness including all plug connections and, if required, replace it.
Possible cause
PCB defective
Measure
Replace the PCB.
Possible cause
Fan defective
Measure
Use D.033 and D.034 to check whether the fan speed deviates by more than 20–30 rpm.
Possible cause
Air-mass flow sensor dirty or defective (only in conjunction with the conversion set comprising the air intake pipe with integrated non-return valve and air-mass flow sensor)
Measure
1. Check the air-mass flow sensor for dirt.
2. If required, replace the entire air intake pipe.
This code also applies to: