Dishwasher Not Draining in Charleston SC

A dishwasher that leaves an inch or two of cloudy water sitting at the bottom of the tub after a cycle is one of the most common service calls we get, and thankfully one of the more affordable to resolve — the cause is almost always a blockage rather than a failed motor.

The first thing our technicians check is the filter assembly at the bottom of the tub, usually a removable cylindrical or flat mesh piece. Food particles, labels from produce, and grease buildup collect here over time, and most manufacturers recommend cleaning it monthly — a step many households skip entirely.

The second check is the air gap, if your installation has one — the small cylindrical fitting on the countertop or sink deck that prevents dirty sink water from siphoning back into the dishwasher. These clog with the same food debris as the filter and are easy to miss since they're not inside the dishwasher itself.

If your dishwasher drains through the garbage disposal instead of an air gap, an unremoved knockout plug is a common cause on newly installed disposals — a plastic plug inside the disposal's dishwasher inlet has to be knocked out during installation, and it's a step that's occasionally missed by installers, blocking drainage completely on an otherwise brand-new setup.

The drain hose itself can kink if the dishwasher was pushed back too far during installation or if a cabinet renovation shifted its position, restricting flow without fully blocking it — this often shows as slow draining rather than no draining at all.

If the filter, air gap, and hose are all clear, the next suspect is the drain pump or a check valve inside the pump housing that can stick in the closed position. This is a more involved repair requiring partial disassembly of the base of the unit.

Our technicians work through these points in order of likelihood, starting with the filter since it resolves a large share of "won't drain" calls without needing any parts — just cleaning.

The $89 service call fee covers this full check. If it turns out to be a simple filter or air gap clog, you're billed for the service call only, with no separate diagnostic surcharge for a fix that didn't need a part.

Standing water left in a dishwasher for several days can develop an odor and encourage mold around the door gasket, so while it's rarely an emergency, it's worth addressing within a few days rather than letting it sit.

If your dishwasher used to drain fine and started slowing down gradually rather than stopping suddenly, that gradual pattern usually points to a filter or air gap that's slowly accumulating debris rather than a sudden mechanical failure.