F.095
The gas valve stepper motor has reached the minimum permissible step number.
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
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
Incorrect gas type set
Measure
Check the gas type and the gas type setting under D.156 and D.157.
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
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
Fault in the electrical connection for the gas valve assembly
Measure
Check the wiring harness between the PCB and gas valve assembly, including all plug connections.
Possible cause
Control electrode defective
Measure
Check and, if required, replace the control electrode.
Possible cause
PCB defective
Measure
Replace the PCB.
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: