You can run it empty with a good chunk of vinegar in the wash - then add it again next wash.

Clogged pipes? Or drains?

Try good old vinegar again....get about 1/2 c of baking soda down the drain.

toss about 1/2 c of vinegar after it and CLOSE THE DRAIN RIGHT AWAY. If it doesn't have a plug, have a wadded up washcloth nearby to block it as much as possible. Give it ten minutes or so - and chase it down with a kettleload of BOILING hot water.