Drain it by hand with a cup and a bucket - take out the filters and go right down to the very bottom of the sump.
When you get there look for a plastic cover help in place with one Torx screw. Remove the cover and expose the impeller of the drain pump. The impeller may well be jammed up with food debris - lemon pips and lead foil from wine bottles - pick it out with tweezers.
The impeller should rotate freely with a bit of magnetic resistance.
Good luck...
Peccavi, February 2013
