Standing water in the bottom of the dishwasher after a cycle is one of the most common calls we get. The good news: a fair number of these have a cause a homeowner can find and fix in fifteen minutes without any tools. The rest come down to a part that has failed and needs replacing. This walks through the causes in the order we actually check them — most common and easiest first — so you can rule things out before deciding whether to call.
An inch or two of clean or slightly cloudy water sitting in the bottom is the symptom. A small amount of water in the sump is normal and keeps the seals from drying out; a pool that covers the bottom of the tub and doesn't go down is not.
Turn the dishwasher off at the panel and, if you'll be reaching into the drain area, switch off the circuit breaker for the kitchen. Bail out the standing water with a cup and a towel first — it makes every check below cleaner and lets you see what's actually happening.
1. The Filter Is Clogged
On nearly every dishwasher built in the last fifteen years, there's a removable filter in the floor of the tub, usually under the bottom spray arm. It catches food debris so it doesn't recirculate. When it packs with grease, labels, seeds, and broken glass, water can't get through to the drain fast enough — or at all.
Twist the cylindrical filter counter-clockwise and lift it out. There's often a flat mesh screen underneath it as well. Rinse both under hot water, scrub with an old toothbrush, and clear anything sitting in the recess where the filter seats. This single step resolves a meaningful share of "not draining" complaints, and a clogged filter is also the most common cause of a dishwasher that cleans poorly.
Pull and rinse the filter once a month if you don't pre-rinse dishes, every couple of months if you do. It's the single highest-value thing you can do for a dishwasher.
2. A New Garbage Disposal With the Plug Still In
This one catches people constantly. If your dishwasher drains into a garbage disposal — most do — and the disposal was recently replaced, there's a good chance the installer left the knockout plug in place. New disposals ship with that drain port sealed by a plastic plug that has to be knocked out before a dishwasher can drain into it. If the dishwasher worked fine until the day a new disposal went in, this is almost certainly the cause.
The fix is to remove the disposal's dishwasher inlet hose and punch out the plug with a screwdriver, then fish the plug out of the disposal so it doesn't jam the grinder. If you're not comfortable doing that, it's a quick job for whoever installed the disposal.
3. The Drain Hose Is Kinked or Clogged
The drain hose runs from the dishwasher pump up to the disposal or sink drain. Two things go wrong with it. It gets kinked — especially if anything was recently stored or moved under the sink, or if the dishwasher was pulled out and pushed back. And it gets clogged with grease and debris, usually right at the bends.
Look under the sink and follow the hose. It should rise in a loop — the "high loop" — up near the underside of the countertop before going down to the drain connection. That loop is what stops dirty sink water from siphoning back into the dishwasher, and a hose lying flat on the cabinet floor can both fail to drain and let water back in.
4. The Air Gap Is Blocked
Some kitchens have an air gap — that small chrome cylinder sticking up next to the faucet. It does the same job as a high loop, and it clogs with the same gunk. If water bubbles up out of the air gap during a cycle, or you see it backing up there, pop the cap off, unscrew the cover, and clear the debris inside. It's a two-minute job and an easy thing to overlook because most people don't know what that little cylinder is for.
5. The Check Valve Is Stuck
The drain pump has a check valve that lets water out and stops it coming back. Over time it can stick — partly open lets water siphon back in, stuck closed stops the drain entirely. This sits inside the machine near the pump, and getting to it means pulling the lower components. This is the point where the job crosses from homeowner territory into technician territory for most people.
6. The Drain Pump Has Failed
If the filter is clean, the hose is clear, the disposal plug is out, and there's still standing water, the drain pump itself is the likely culprit. A failed drain pump usually shows up one of two ways: complete silence where you'd expect to hear the pump run during the drain portion of the cycle, or a humming or buzzing without water actually moving. Pumps fail from worn motors, from broken impellers, or from a shard of glass or a fruit pit jamming the impeller.
Diagnosing a pump means testing it for continuity and checking whether something is physically blocking the impeller. Replacing one means accessing the pump, swapping it, and reconnecting the drain and electrical — a job with water and power involved, where the part has to match the model. This is a standard repair for a technician and not a DIY job for most homeowners.
Clean the filter → check for a recent disposal install with the plug left in → check the drain hose for kinks and the air gap for clogs → if all clear, the problem is inside the machine (check valve or pump) and worth a service call.
When to Call
Work through the first four checks — filter, disposal plug, drain hose, air gap. They're safe, free, and they resolve a large share of drainage problems. If you've done those and water is still standing, the fault is the check valve or the drain pump inside the machine, and that's a diagnosis and repair worth handing to a technician rather than disassembling the unit yourself.
For an older dishwasher, the repair-versus-replace math matters too. A drain pump on a mid-range dishwasher is usually well worth repairing. On a unit that's already past ten or twelve years old and showing other problems, we'll tell you honestly where that line is rather than sell you a repair that doesn't make sense.
Dishwasher still holding water?
We diagnose the cause and give you a price before any work begins — across Mechanicsburg, Harrisburg, Camp Hill, Carlisle, and the surrounding area.