Why is my Wdal 8640 continuously filling with water and draining away?

The most likely cause is that the top of the drain hose is positioned too low — it must be fitted at a height between 65 and 100 cm from the floor. The drain hose may also be connected incorrectly to the sink trap, or the end of the drain hose may have been pushed too far down the standpipe. Check that the 'U' bracket is fitted 100 mm from the end of the drain hose. (Page 13)