how can i fix my Howden,HDA/HJA 8630 dishwasher?

My dishwasher goes through the wash cycle then doesn't drain the water,it also took a while to start.... Humming for a few minutes more than normal so I gave it a few taps at the bottom where the pump is and it went right through the wash cycle,at the end of the wash I had to drain it by hand.Do I have to reset the pump to make it work?Water is also dripping from around the middle underneath.The last time this happened it was the seal connected to the pump.