A dishwasher that finishes its cycle and leaves a pool of dirty water in the bottom is one of the most common calls we get. The good news: about half the time it’s a clog you can clear yourself in twenty minutes. The other half needs a tech. This guide covers both, starting with the cheapest fix.
Before you start, a note on the normal stuff. A small amount of clean water in the sump (the recessed well at the bottom) is supposed to be there. It keeps the pump seals from drying out. The problem is an inch or more of cloudy water that won’t go away after a full cycle.
Start with the filter
Most modern dishwashers have a removable filter sitting flush in the floor of the tub, under the bottom spray arm. Food, grease, and broken glass collect there. When it packs solid, water can’t reach the drain.
Pull the bottom rack out. Twist the cylindrical filter counterclockwise and lift it free. Rinse it under hot water, scrub the mesh with an old toothbrush, and clear any debris from the opening underneath. Drop it back in and lock it. This single step solves a large share of no-drain complaints, and it’s the first thing we check on a service call.
Check the garbage disposal and air gap
Your dishwasher drains into the same plumbing as your kitchen sink. Two things on that path cause trouble.
If you have a garbage disposal, the dishwasher hose usually connects to it. New disposals ship with a knockout plug in that inlet. If a recent install skipped removing the plug, the dishwasher has nowhere to drain. Run the disposal to clear any food packed at the connection, then check whether water moves.
The air gap is the small chrome cylinder on the back edge of the sink, next to the faucet. It stops dirty sink water from siphoning back into the dishwasher. Pop the cap off, unscrew the cover, and look for sludge inside. Clean it out. A clogged air gap will leave water in the tub and sometimes spit it onto the counter.
Inspect the drain hose
The drain hose runs from the dishwasher pump up under the sink. Two failure modes: a kink where it got pinched during an install, and a clog where grease has narrowed the inside diameter over years of use.
Pull the dishwasher’s lower access panel and find where the hose connects. Check that it isn’t crushed against the cabinet. The hose is supposed to loop up high before it drops to the disposal or drain — that high loop prevents backflow. If the loop has slipped down, water siphons back in. For an internal clog, disconnect the hose at the disposal end over a bucket and run water through it.
When it’s the drain pump
If the filter is clean, the disposal and air gap are clear, and the hose runs freely, the drain pump is the next suspect. The drain pump is a separate motor from the wash pump, and it’s the part that physically pushes water out at the end of the cycle.
Two things kill it: a shard of glass or a fruit pit jamming the impeller, and a burned-out motor or seized bearing. You’ll sometimes hear a hum with no water movement, or a grinding noise. Testing the pump means pulling power, accessing the pump housing from the base, and checking the impeller and the motor windings with a meter. That’s the line where most people should call a tech rather than dig into live wiring and water.
When to call ADRIUM
Clear the filter, disposal, air gap, and hose yourself. Those are clean, no-tool-or-meter fixes. Call us when the water stays put after all of that, when you hear the pump straining, when there’s a burning smell, or when the unit throws a drain error code and won’t reset. For a broader rundown of dishwasher faults — leaks, heating, control boards — see our dishwasher repair guide, or read about our dishwasher repair service.
We charge a flat $75 diagnostic, credited toward the repair when you book the work. We service the full Tri-Valley and serve Bosch, KitchenAid, Whirlpool, Samsung, LG, and more. CSLB #1136642, BEAR #50788, A+ with the BBB, in business since 2021.
Call (925) 999-4095 or email [email protected] to get on the schedule. You can also reach us through the contact page.
FAQ
Why is there standing water in the bottom of my dishwasher? A shallow pool of clean water in the sump is normal. An inch or more of dirty water that won’t drain points to a clogged filter, blocked hose, plugged air gap, full disposal, or failed pump.
Can I run my dishwasher if it won’t drain? Not a full cycle. Clear the clog first, run a short rinse to test, and stop if it still holds water so you don’t flood the cabinet.
How often should I clean the filter? Monthly for a busy kitchen, every two to three months if you rinse plates first. It twists out by hand.