I may have had a similar problem recently. My good wife had been rinsing ware before putting them into the dishwasher. Over time, there was always some very very small residue of Fairy Liquid left on the plates etc that mixed with the tablet in the machine to create a pile of bubbles. This was going on for a while and eventually left a load of waste water in the tray underneath the dishwasher (as I understand it). The fact that there was water in the tray prevented the dishwasher from opearting correctly. It made all the huming noises but there was not water intake. I know this because I had rang up Whirlpool and they sent someone out to fix it. Cost me €70. Hope that helps.