Regardless of wether or not it was a display, it should still carry the manufacturer's warranty, and you should've received all the paperwork with it. Aside from that, it sounds like exactly what mine was doing when it wasn't draining properly. Check the bottom of the dishwasher for standing water. And you should be able to see the water flow thru your garbage disposal when it drains. (We had a napkin caught in our drain pipe and wound up tearing the whole pump apart looking for it.) If everything's hooked up properly and it seems to be draining all the water when its suppose to, then I would contact the manufacturer. Even if you didnt get the paperwork with the unit, there will be a label on it somewhere that has the serial and model #'s, the manufacture date, and a contact number. That will be enough info to get a service tech out to look at it. :}