A dishwasher that finishes its cycle with a pool of dirty water in the bottom is one of the calls we run most at Bay Area Appliance Repair Service. About half the time it’s a clog you can clear in twenty minutes. The other half needs a tech. Work it in order and you’ll know which one you’ve got before you spend a dime.
One thing up front. A thin film of clean water down in the sump, the little 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 leave after a full cycle.
Clear the filter first
Almost every dishwasher built in the last fifteen years has a removable filter in the tub floor, under the lower spray arm. Grease, food, and the odd shard of glass collect there until it packs solid and water can’t reach the drain.
Pull the bottom rack. Twist the cylindrical filter counterclockwise and lift it out. Rinse it under hot water, work an old toothbrush through the mesh, and clear whatever’s sitting in the opening below. Drop it back and lock it. This one step fixes a big share of no-drain calls, and it’s the first thing we do on a service visit anyway.
The sink side: disposal and air gap
Your dishwasher shares drain plumbing with the kitchen sink, and two spots on that run cause most of the rest.
If you have a garbage disposal, the drain hose ties into it. New disposals ship with a plastic knockout plug in that inlet. If a recent install left it in, the dishwasher has nowhere to go. Run the disposal to clear food packed at the connection, then check whether water moves.
The air gap is the little chrome cylinder on the back edge of the sink, next to the faucet. Pop the cap, unscrew the cover, and look for sludge. Clean it out. A plugged air gap holds water in the tub and sometimes spits it up onto the counter.
Hose and pump: where the tech comes in
Filter, disposal, and air gap all clear and water still sits? Now it’s the hose or the pump, and both are ours to handle.
The drain hose runs from the pump up under the sink. A kink stops it, and so do years of grease narrowing the inside. It’s supposed to loop up high before it drops to the disposal. If that loop sags, water siphons back into the tub. Clearing an internal clog or re-routing the hose means pulling the lower panel and breaking plumbing loose. Easy to get wrong, and a slow leak you miss for a week does real cabinet damage.
The drain pump is what physically pushes water out at the end. A pit or a bit of glass jams the impeller, and a burned motor hums without moving anything. Testing means checking the impeller and motor windings with a meter, live electrical near water, so leave it to a tech. A pump runs $90 to $220 in parts on most brands. Worth getting right.
Watch a pump-and-sump leak
When to call us
Clean the filter, run the disposal, clear the air gap. Twenty minutes, no tools. If the water stays after all of that, call us. Same if the pump strains, you smell something burning, or a drain error code won’t clear.
For the broader rundown of dishwasher faults, leaks, no-heat, dead control boards, see our dishwasher repair guide, or what our dishwasher repair service covers.
We work on Bosch, KitchenAid, Whirlpool, Samsung, LG, Maytag, GE, and the rest across the Bay Area, often same or next day when slots are open. It’s a $75 diagnostic, credited to the repair, and you get a repair-or-replace call and price once we find the fault. CSLB #1136642, BEAR #50788, A+ with the BBB.
Call (925) 999-4095 or email [email protected]. You can also reach us through the contact page.
FAQ
Why is there standing water in the bottom of my dishwasher? A thin film of clean water in the sump is normal. An inch of dirty water that won’t drain points to a packed filter, blocked hose, plugged air gap, full disposal, or a dead pump.
Can I run it while it won’t drain? Not a full cycle. Clear the clog, 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.