Sounds like you either have a leak which has activated the flood safety in the base, you can check this by pulling the machine onto a towel and tipping the whole unit forward ie raise the back of the machine off the floor so it is pivoted on the front feet at approx 45 degrees, if water runs out from under the machine you have a leak (the machine may well start to work again now but you need to trace the leak or it will reoccur as soon as the safety is activated again). The other possibility is the pressure chamber or hose (pressure chamber to sump) is blocked and the microswitch is being activated because the water is not entering the tank quick enough. Isolate from electric, remove lid and left panel (looking from the front). There is a plastic chamber bottom right of left side with two microswitches, either this is blocked or the hose that runs from it to the right and along the back of the kick panel and into the sump. Clear either or both (make sure all hoses are pushed true when repositioning). You can also try putting in a kettle full of hot water, close the door (don't start the d/w) let it sit for about 30mins and then try the machine, after periods of non use, sometime the seals can dry out this will plump them back up. Post back if you need more info.