Recent content by AMBal

Have a look at my thread here, same boiler (different size), same issue. The bypass needs to be installed and set correctly, the pump cannot be run in modulating mode, needs to be constant. https://www.diynot.com/diy/threads/vaillant-ecotec-plus-430-f83-error-code.495145/#post-5108110

Hi Yes, apologies I should have come back to this. We did resolve it. The root cause was the installer was basically a numpty. Amongst a load of other (now resolved) issues which I don’t think are relevant here (reverse circulation, UFH pump installed before main pump) the ABV had been...