F.088
The electrical connection to the gas valve has been interrupted.
Vaillant ecoTEC Plus Combi
Possible cause
Gas valve assembly not connected
Measure
Check the connection to the gas valve assembly.
Possible cause
Gas valve assembly connected incorrectly
Measure
Check the connection to the gas valve assembly.
Possible cause
Short circuit in the wiring harness
Measure
Check the wiring harness and, if required, replace it.
This code also applies to: