Why Is My Dishwasher Not Draining?
Updated June 2026 · 2 of these 5 fixes are free
Clean the drain filter first — it's at the bottom of the tub, and a clogged filter causes 40% of dishwasher drain failures. If that doesn't fix it, check under the sink for a kinked drain hose or a missing garbage disposal knockout plug. If the pump is bad, expect $150—$250 for replacement.
5 Causes (Check in This Order)
1. Clogged Drain Filter (#1 Cause)
Every modern dishwasher has a removable drain filter at the bottom of the tub — it looks like a cylindrical mesh screen. Food particles, grease, and debris accumulate here and block water from draining. Fix: Remove the bottom rack. Locate the filter (usually in the center or back corner of the tub floor). Twist it counterclockwise to remove. Rinse it under hot running water and scrub with a soft brush. Reinstall it and run a short cycle. Maintenance tip: Clean this filter once a month. In Florida's hard water, mineral buildup compounds the clogging.
2. Kinked or Blocked Drain Hose
The drain hose runs from the dishwasher to your sink drain or garbage disposal. Open the cabinet under the sink and check: is the hose kinked? Is it squished by something stored under the sink? Straighten any kinks. If the hose isn't kinked, disconnect it from the disposal/drain and check for internal clogs — food debris can build up inside the hose over time, especially at the disposal connection point.
3. Garbage Disposal Knockout Plug
If you recently had a new garbage disposal installed and your dishwasher suddenly won't drain, this is almost certainly the problem. New garbage disposals come with a plastic knockout plug inside the dishwasher drain inlet. This plug must be removed before connecting the dishwasher drain hose. If your installer forgot to knock it out (happens more than you'd think), the dishwasher water has nowhere to go. Fix: Turn off the disposal's breaker. Look into the disposal drain inlet (where the dishwasher hose connects). Use a screwdriver and hammer to push out the knockout plug, then retrieve it from inside the disposal. Also: if your disposal is jammed, it can block dishwasher drainage too.
4. Failed Drain Pump
The drain pump pushes water out of the dishwasher tub and through the drain hose. When it fails, you might hear a humming sound (the motor trying to run but the impeller is stuck) or nothing at all. A failed drain pump is the most common reason a dishwasher won't drain after you've already cleaned the filter and checked the hose. Cost: $150—$250.
5. Air Gap Blockage
Some kitchens have an air gap — a small chrome or stainless cylinder mounted on the countertop next to the faucet. It prevents sink water from backing up into the dishwasher. If the air gap clogs with debris, water can't drain from the dishwasher. Fix: Remove the chrome cap and inner cover. Clean out any debris. Run water through it to confirm flow. Not all dishwashers have an air gap — many use a high drain loop instead (the drain hose is looped up high under the countertop).
A small amount of water (about 1 cup) in the bottom of the dishwasher tub is normal — it keeps the pump seal lubricated and prevents the seal from drying out and cracking. If you see 1—3 inches of murky, food-particle-laden water, that's a drainage problem. Also: before assuming the dishwasher is broken, check if your kitchen sink drains normally. If both the dishwasher and sink won't drain, the problem is in your home plumbing, not the dishwasher — call a plumber instead of an appliance tech.
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