hi i had that trouble with mine dont think its your pump the filter probley blocked ours had cotton buds and bra wires and hair bands are main probs any way back to ur problem detach it from the plug and pipes get it out side and tip it on its back if you can,t get the back off you,ll see a fat pipe with a plastic cap or bottle attached to it try undoing the pipe to get to the cap the water will pour out try opening the filter cap .clean it out put back together and rinse it should be ok.
markmac
December 2009