Dishwasher not draining is the #1 dishwasher call we get in Memphis. Good news: 7 times out of 10, it's something you can fix yourself in under 30 minutes.
Start with the filter (yes, your dishwasher has one)
Modern dishwashers have a removable filter at the bottom. Pull out the lower rack, unscrew or twist the filter cylinder, and rinse it under hot water. If it looks like a science experiment, that's your problem. Brands vary on filter location — Bosch, KitchenAid, and Whirlpool have obvious cylindrical filters; older Frigidaire models hide it under the spray arm.
Check the drain hose
Pull the dishwasher out (carefully — the water line and electrical run underneath). The drain hose loops up to the disposal or air gap. If it has a sag, water sits and food debris dries inside. Straighten any low spots and check for kinks where it meets the cabinet wall.
Garbage disposal connection
If your dishwasher drains into a garbage disposal, check the dishwasher knockout plug. When a new disposal is installed, the installer sometimes forgets to knock out the plug — your dishwasher has nowhere to drain. Look at the disposal port; if you see a plastic plug, it needs to come out.
Drain pump check
Listen during the drain cycle (about 30 seconds after start). You should hear a brief humming as the pump kicks in. If you hear nothing, the pump is dead. If you hear it humming but no water moves, something is jammed in the impeller — usually a piece of glass or a fruit pit.
The air gap (if you have one)
That little chrome dome on top of your sink is an air gap — it prevents dirty drain water from siphoning back into the dishwasher. If it's clogged, water has nowhere to go. Unscrew the cap, lift off the dome, and rinse out the debris.
Still stuck?
If you've checked all five and the dishwasher still won't drain, the control board may have lost the drain-pump output. We see this often on older Whirlpool, GE, and Frigidaire models. Call us at (901) 562-9437 and we can usually fix it same-day.