Your outlet pump is blocked or faulty. Probably full of mush. Clean out the filter (if it has one) or clean out the pump. Make sure it turns. Reconnect any hoses that you disconnected to get at it. The machine should work. If it doesn't the outlet pump could have failed completely in which case fit a new one - not expensive. Always disconnect from the mains supply before starting any work on it. (Risk of shock)
Chicks Fan, November 2008