My waterwall dishwasher is about 4.5 years old. It recently started stopping half way through a cycle (sometime not even getting that far), blue light flashing, code OC (this means drainage overflow). We did have a kink in the hose which has now been fixed, but still, it isn't working. When I open the dishwasher once the error code comes on, I can hear a sucking noise (no water at the bottom of the dishwasher or in the sump). sometime the water does go through (we disconnected the pipe where it attaches to the sink and we see the water flowing through).
What else can we check before getting an engineer in?