Dishwasher Not Draining: What to Check Before You Call
By the FixPro Appliances technicians · Updated September 8, 2026
An inch or two of water in the bottom of the dishwasher after the cycle ends is the most common dishwasher complaint we get. Half of the time the fix is something you can do at the sink in ten minutes. The other half is a drain pump or check valve, which is a routine one-visit repair.
First: bail it and clear the filter
Scoop out the water with a cup and sponge. Remove the lower rack and twist out the cylindrical filter in the floor of the tub (most models made after 2010 have one; older ones have a flat screen). Rinse it, and look into the sump underneath for glass, a fruit label, a toothpick or a broken piece of a wine glass — those are what jam drain impellers.
The garbage disposal knockout plug
If the dishwasher stopped draining right after a new garbage disposal was installed, this is your answer. New disposals ship with a plastic knockout plug in the dishwasher inlet that must be punched out before connecting the hose. Installers forget it constantly. Disconnect the dishwasher hose from the disposal (bucket underneath), and if the inlet is solid, that plug needs to come out.
The drain hose and the air gap
Under the sink, follow the dishwasher drain hose. It should rise in a high loop up under the counter before dropping to the disposal or drain — without that loop, sink water backs into the dishwasher. Check that the hose is not kinked behind the dishwasher or pinched by something under the sink. If you have an air gap (the chrome cylinder on the sink deck), pull its cap and clear the gunk; a blocked air gap stops the drain cold.
Run the disposal
If the dishwasher drains into the disposal, a full disposal means a full dishwasher. Run the disposal with water for 30 seconds and try a drain-only cycle (most dishwashers: hold the start or cancel button for 3 seconds).
When it is the pump
If the filter is clean, the hose is clear and the dishwasher hums but the water stays, the drain pump impeller is jammed or the pump motor has failed. Some models also have a check valve that sticks shut. Bosch reports this as E24 or E25; Samsung as 5C or 5E; LG as OE. These are the same repair: pump or valve, done in one visit.