On the common GE orbital spray arm dishwasher there are several common things to check for. The lower spray arm has had trouble with the underneath part wearing out and holes are visible on the underneath side of the spray arm. The nut and seal often wear out and water leaks around the lower spray arm rather than going into the spray arm. The back flush gasket seal inside the spray arm base also wears out and the water cannot fully go into the spray arm. Low water fills may also allow the heating element to burn holes on the underneath part of this spray arm.