What's the best way to clear a blocked dishwasher drain line?

MEP Plumbing
2

Dishwasher drain lines typically run under the sink. They attach to the garbage disposal or a barbed fitting on the tubular drain pieces under the sink. The drain line is held on by a hose clamp. You can simply take the clamp off and drain the line or attempt to remove any obstructions that are visible.

If the dishwasher is not draining, it is very rarely related to the drain line itself. Either a garbage disposal is installed and the knockout is left intact, or the pump on the dishwasher has failed.

3

The dishwasher drain hose connects to the garbage disposal or to the tailpipe of the drain if there is no disposal. It comes in 3 sizes: 5/8", 3/4" or 1". The hose might be with or with corrugation, and connected with 2 metal clamps.

If this hose is clogged, unscrew clamps and remove hose. Use something stiff, like a drain snake, a wire or something that can push the obstruction in the hose out. Reinstall in the reverse order and run dishwasher to verify the blockage is no longer there.