How to Fix a Dishwasher That Won't Drain

Check the Basics First

Before investigating plumbing issues, check whether the dishwasher's filter basket (located at the bottom of the tub) is clogged with food debris. Remove the lower dish rack, locate the filter (usually a twist-off cylinder), and clean it thoroughly. Also check the drain area around the filter for broken glass, food particles, or foreign objects that might block the drain pump impeller. Many newer dishwashers have a fine mesh filter that requires regular cleaning — some manufacturers recommend weekly cleaning for optimal performance.

Inspecting the Drain Hose

The drain hose runs from the dishwasher pump to either the garbage disposal inlet or an air gap on the countertop. Pull the dishwasher out slightly (after disconnecting power) and inspect the drain hose for kinks, sags, or pinches that restrict water flow. The hose should loop up to the underside of the countertop before descending to the disposal connection — this high loop prevents backflow from the sink or disposal. If the hose is old and deteriorating, replace it with a new one.

Garbage Disposal Connection

If your dishwasher drains through the garbage disposal, a common problem is a clogged disposal or the knockout plug still being in place. Run the garbage disposal for 30 seconds with water running to clear any blockage. If you recently installed a new disposal, check that the dishwasher inlet knockout plug was removed — it must be punched out from inside the disposal to create the opening for the drain hose. Not removing this plug is one of the most common post-installation mistakes.

Drain Pump and Motor

If the drain hose and disposal connection are clear but water still does not drain, the dishwasher's drain pump or motor may be faulty. Listen during the drain cycle — you should hear the pump motor running. If there is no sound, the motor may have failed or its wiring may be damaged. If the motor runs but water does not drain, the pump impeller may be broken or jammed. Drain pump replacement is a manageable DIY repair for most dishwasher models — the pump is typically accessible from the bottom of the unit. Disconnect power, remove the lower access panel, and follow model-specific instructions for pump replacement.