F.076
The overheating protection for the primary heat exchanger is active.
Vaillant ecoTEC Plus Combi
Possible cause
Open circuit in wiring harness (LIN cable)
Measure
Check the wiring harness (LIN cable).
Possible cause
Interruption in the wiring harness
Measure
Check the wiring harness including all plug connections and, if required, replace it.