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The short answer: a dishwasher that will not drain almost always has a clog in the filter, sump, or drain hose, or a knockout plug left in a newly installed garbage disposal. Scoop out the standing water, remove and clean the filter at the bottom of the tub, check the drain hose for kinks and clogs, run the garbage disposal, and confirm the air gap is clear. These free checks fix the large majority of cases. Only a failed drain pump or solenoid needs a professional. Work through them in order before calling for repair.
Standing water in the bottom of the dishwasher is alarming but usually cheap to fix. The drain path is simple — water leaves the tub through a filter and sump, gets pushed by a pump through a hose, and exits via the garbage disposal or a sink tailpiece, often past an air gap. A blockage anywhere along that path leaves water sitting in the tub. Find the blockage and you have found the fix. We do not physically test appliances; this reflects manufacturer guidance and owner-repair consensus, as explained in how we rank.
First: cut power to the dishwasher and bail the water
Before troubleshooting, make the work area safe and clear:
- Turn the dishwasher off and, for anything beyond a filter clean, cut power at the breaker or unplug it — you will be near water and electrical components.
- Scoop out the standing water with a cup into a bucket, then sponge the last of it from the sump. Working in a dry tub lets you see and reach the drain.
- Lay towels down in front of and under the unit.
A small amount of clean water sitting in the sump between cycles is normal and by design — it keeps seals from drying out. The problem is dirty water that stays after a full cycle.

Fix 1: clean the dishwasher filter (the most common cause)
Nearly every modern dishwasher has a removable filter in the bottom center of the tub, and a clogged one is the single most common drainage culprit. Food, grease and grit pack it solid.
- Remove the lower rack to reach the filter.
- Twist the cylindrical filter counterclockwise to unlock it and lift it out, along with the flat mesh screen under it on many models.
- Rinse it under hot water and scrub with a soft brush and dish soap to clear trapped food, grease and glass shards. Wear gloves — broken glass hides here.
- Clear debris from the filter recess and sump where the filter sat.
- Reinstall the filter, twisting until it locks. A filter that is not locked in can rattle and let food bypass it.
Manufacturers recommend cleaning the filter monthly; most people never do until it clogs. This one step resolves a large share of no-drain problems.
Fix 2: run the disposal and check the knockout plug
Most dishwashers drain through the garbage disposal, so the disposal is part of the drain path:
- Run the disposal with cold water for several seconds to clear its chamber and drain line, then try the dishwasher drain cycle again. A full or clogged disposal backs up the dishwasher.
- Check the knockout plug if the dishwasher stopped draining right after a new disposal was installed. Disposals ship with a solid plug sealing the dishwasher inlet that must be knocked out before the hose is connected. Left in place, water has nowhere to go — this is one of the most common installation mistakes.
To check, disconnect the dishwasher drain hose from the disposal inlet, reach in, and confirm the plug was removed and the knocked-out piece is not loose inside the disposal.
Fix 3: check the drain hose
The drain hose runs from the dishwasher pump to the disposal or sink tailpiece, and it clogs or kinks:
- Pull the dishwasher out or open the cabinet under the sink to access the hose.
- Look for kinks, especially where the hose loops up or bends behind the unit. Straighten any you find.
- Disconnect both ends (bucket underneath) and check for clogs. Run water through it or push a straightened wire hanger through to clear debris.
- Confirm the high loop or air gap. The hose should loop up high under the counter, or connect to an air gap on the sink, to stop dirty water siphoning back. A missing high loop causes drainage and backflow problems.
A grease clog in the hose is common; hot water and mechanical clearing usually free it.

Fix 4: clear the air gap
If your sink has a small chrome cylinder on top (the air gap), it can clog and stop drainage, sometimes spurting water onto the counter during a cycle.
- Twist off the cap and lift out the cover.
- Clear any debris inside with a bottle brush or a blast of water.
- Check the hose from the air gap to the disposal for a clog too.
Not every setup has an air gap; many use a high loop instead. If yours has one, it is a quick, free thing to rule out.
Fix 5: force a drain cycle to reset the dishwasher
Sometimes a cycle was interrupted mid-run and water was left behind. Running a dedicated drain resets it:
- On most machines, press Start, wait a moment, then press Cancel (or Cancel/Drain) and close the door. The machine pumps out standing water over one to two minutes.
- Listen for the pump. A humming pump that moves no water suggests a jam or failure; a silent pump suggests no power or a control fault.
- Use this to test any fix — after cleaning the filter or hose, run a drain to confirm water now leaves the tub.
Check your model's manual for the exact button sequence, which varies by brand.
Fix 6: check the drain pump and valve
If the path is clear but water still will not drain, the problem may be mechanical — this is where DIY starts to end for most people:
- Drain pump jam: with power off, remove the sump cover at the bottom of the tub and check the pump impeller for glass or debris jamming it. Clear carefully with gloves.
- Failed drain pump: a pump that hums but moves nothing, or is silent with power confirmed, has likely failed and needs replacement.
- Drain solenoid or check valve: on some machines a valve directs water to drain; a stuck valve blocks it.
Replacing a drain pump is doable for a confident DIYer but involves removing panels and disconnecting wiring and plumbing. If you are not comfortable, this is the point to call a pro.

When to call a pro, and what it costs
Call a professional for electrical faults, a failed pump you would rather not replace yourself, or any leak onto the floor. Rough US figures as of 2026, which vary by region and brand, so treat them as a guide and get a local quote:
| Job | Typical US cost (2026) |
|---|---|
| Diagnostic / service call | $100 to $300 |
| Drain pump replacement (parts + labor) | $150 to $400 |
| Drain hose replacement | $100 to $250 |
| Control board repair | $150 to $400+ |
Because the free checks — filter, disposal, knockout plug, hose, air gap — fix most no-drain cases, always work through them before paying for a service call. If a repair estimate approaches half the price of a new dishwasher on a unit over about eight years old, replacement usually makes more sense.
Preventing your dishwasher from not draining again
- Scrape plates before loading; the filter chokes on food debris.
- Clean the filter monthly — the habit that prevents most clogs.
- Run the disposal before running the dishwasher so its drain path is clear.
- Run an empty hot cycle with dishwasher cleaner or vinegar periodically to cut grease in the drain path.
These habits keep the drain path clear and make a repeat no-drain unlikely.
Related kitchen fixes
Since the dishwasher often shares a drain with the sink, a backed-up disposal is a common companion problem — see how to clean a garbage disposal and how to reset a garbage disposal. For keeping other appliances draining and running, browse the small kitchen appliances hub, and see how we rank for our review method.
