Dishwasher Not Draining? Try These Fixes Before Calling a Tech

Opening your dishwasher to find an inch of standing water at the bottom is a frustrating way to end a wash cycle. The good news: dishwasher drainage problems are among the most common appliance issues we see, and the cause is often something you can check yourself before calling a technician.

Step 1: Clean the filter. Most modern dishwashers have a removable filter at the bottom of the tub. Twist it out, rinse it under warm water, and use a soft brush to remove any food debris. A clogged filter is the number one cause of poor drainage — and cleaning it takes under five minutes.

Step 2: Check the drain hose. The drain hose connects the dishwasher to your sink drain or garbage disposal. Make sure it isn't kinked behind the machine. Also check that it forms a high loop under the counter — without this loop, water from the sink can siphon back into the dishwasher.

Step 3: Check the garbage disposal knockout plug. If your dishwasher was recently installed alongside a new garbage disposal, there may be a knockout plug still in place inside the disposal's dishwasher inlet. This plug must be removed for the dishwasher to drain. It's a quick fix but easy to overlook.

Step 4: Inspect the drain pump. If the filter is clean and the hose is clear, the drain pump may be blocked by debris. You'll often hear a humming sound as the pump tries to run. Accessing the pump requires removing the lower spray arm and filter assembly — this is where most homeowners call a technician.

Step 5: Check the door latch and cycle completion. Some dishwashers won't complete the drain cycle if the door was opened mid-cycle. Try running a short cycle from start to finish without interrupting it. If the machine drains at the end of a full cycle but leaves water after a partial cycle, the door latch or control board may need attention.

If you've worked through these steps and the dishwasher still won't drain, the drain pump likely needs to be replaced. GTA Appliance Pros handles dishwasher repairs across the GTA — call (647) 996-7555 or book online for same-day service.