Appliances guide
Dishwasher not draining: clear the filter, drain path and pump
By the Home Doctor team · Reviewed
Quick answer
Standing water in a dishwasher usually means a clogged filter, a garbage disposal that's full or still has its knockout plug in, a clogged air gap, or a kinked drain hose. Run the disposal for 20 to 30 seconds first, since the dishwasher drains into it, then clean the filter under the lower spray arm and the air gap cap by the faucet. If the pump hums or stays silent and nothing drains, the drain pump has likely failed, typically $200 to $450 for an appliance tech to replace.
- How urgent
- Fix soon
Not dangerous, but the water turns sour within a day or two and a blocked drain can back up into the sink. It's more pressing if water reaches the floor or the wiring under the kick panel.
- DIY or pro
- DIY
Running the disposal, cleaning the filter and the air gap, and knocking out a disposal plug are DIY with a screwdriver. Pulling the dishwasher out to reach the hose, or replacing the drain pump, is a job for a handy homeowner or an appliance tech.
Stop and call a pro now if
- You need to bail out water, pull the filter or reach into the sump: unplug the dishwasher or switch off its breaker first, and wear gloves. Broken glass often collects in the sump.
- A cycle just ended: let the water cool for 20 to 30 minutes before you reach in. Wash and sanitize water can be hot enough to scald.
- Water is leaking onto the floor or under the kick panel, where the wiring connects: switch off the breaker before you mop up or take the panel off.
- Burning smell or smoke from under the dishwasher: switch it off at the breaker and don't run it again until it's checked.
Common causes and how to tell them apart
1. Clogged filter
- How to tell
- Dirty water sits over the filter in the floor of the tub, bits of food are left on dishes, and there's a sour smell. Most newer dishwashers have a filter you clean by hand.
- What fixes it
- Twist the filter out, usually a quarter turn counterclockwise, and scrub it in the sink with a soft brush and warm soapy water. Wipe out the sump and lock the filter back in. Clean it every month or so.
2. Full garbage disposal or clogged sink drain
- How to tell
- The sink drains slowly, or water rises in the sink when the dishwasher drains. On a sink without a disposal, the hose connects to a branch fitting under the sink that can clog with grease.
- What fixes it
- Run the disposal with cold water for 20 to 30 seconds before every load. If the sink itself is slow, clear the trap or snake the drain first: the dishwasher can't drain into a blocked line. Skip chemical drain cleaners.
3. Clogged air gap or no high loop
- How to tell
- Water spurts out of the small chrome or plastic cap next to the faucet when the dishwasher drains. With no air gap, the drain hose under the sink lies flat on the cabinet floor instead of looping up.
- What fixes it
- Pull the air gap cover off, unscrew the cap underneath and clear the gunk with a bottle brush. With no air gap, fasten the hose as high as it will go under the counter (a high loop) so sink water can't run back into the dishwasher.
4. Knockout plug left in a new disposal
- How to tell
- The dishwasher stopped draining right after a new garbage disposal was put in.
- What fixes it
- With the disposal unplugged, take the dishwasher hose off the inlet on the side of the disposal, tap the plastic plug out with a screwdriver and hammer, and fish it out of the disposal with tongs.
5. Kinked or clogged drain hose
- How to tell
- The filter, disposal and air gap are clear but water still sits. Often right after the dishwasher was installed or pushed back into the cabinet.
- What fixes it
- Straighten a kink, or replace a crushed hose. To check for a clog, take the hose off at the disposal or sink end over a bucket and run a Drain cycle. If water pumps out freely, the blockage is past the hose.
6. Failed drain pump or stuck check valve
- How to tell
- At the drain step you hear a hum with no water moving, grinding or rattling, or nothing at all. The display may show a drain error.
- What fixes it
- With the power off, pull the filter and look in the sump for glass, fruit pits or bones near the pump. On some models a small cover pops off so you can clear the impeller. A pump that still won't run, or a check valve stuck shut, needs replacing.
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What you can safely try first
- 1Run the garbage disposal with cold water for 20 to 30 seconds. Then press Cancel or Cancel/Drain on the dishwasher and listen for a couple of minutes.
- 2If water still sits, let it cool, then unplug the dishwasher or switch off its breaker. Put towels down and bail the water into a bucket with a cup and a sponge.
- 3Twist out the filter, rinse it in the sink, and wipe out the sump with gloves on.
- 4If you have an air gap by the faucet, pull off its cover, unscrew the cap and clear any debris.
- 5Look under the sink: the drain hose should loop up high, not be kinked, and be clamped tight. If the disposal is new, check that the knockout plug was removed.
- 6Restore power, run the disposal again, and start a short Rinse or Drain cycle to test it.
When to call a pro
- The pump hums, grinds or stays silent after you've cleaned the filter and cleared the drain path.
- Water leaks onto the floor or from under the kick panel.
- The sink drain is clogged past the trap and a hand snake won't clear it.
- A drain error code keeps coming back after a reset.
What it costs
| Job | DIY parts | Pro, installed |
|---|---|---|
| Appliance repair diagnostic visit | — | $75–$200 |
| Clean the filter and air gap | $0–$10 | — |
| Replace the drain hose | $15–$40 | $150–$300 |
| Replace the drain pump | $40–$150 | $200–$450 |
| Clear a clogged kitchen sink drain | $0–$50 | $125–$350 |
| Replace a standard built-in dishwasher | $400–$1,200 | $600–$1,800 |
Ballpark US ranges as of September 28, 2026. Your region, access and the specifics of your home can move these a lot. Get two or three quotes for anything over a few hundred dollars.
What to tell the pro
My dishwasher, about [age] years old, leaves [a little / several inches of] water in the bottom after every cycle. It drains through [an air gap / a high loop] into [a garbage disposal / the sink drain]. I've [run the disposal / cleaned the filter / cleared the air gap / checked the hose for kinks] and it still won't drain. At the drain step I hear [a hum / grinding / nothing], and the display shows [error code / no code]. Is it worth repairing at this age, and does your price include the part and labor?
Questions people ask
Why is my dishwasher not draining?
Usually a clogged filter, a garbage disposal that's full or still has its knockout plug in, a clogged air gap, or a kinked drain hose. Run the disposal, then clean the filter and the air gap first. If it still won't drain and you hear a hum or nothing at the drain step, the drain pump has likely failed.
Why won't my dishwasher drain after installing a new garbage disposal?
The knockout plug was probably left in. New disposals come with a plastic plug sealing the dishwasher inlet, and it has to be knocked out before the dishwasher can drain. With the disposal unplugged, take off the dishwasher hose, tap the plug out with a screwdriver and hammer, and remove it from inside the disposal with tongs.
Is it normal to have water in the bottom of the dishwasher?
A small amount, yes. Many models keep a little clean water in the sump under the filter to keep the seals from drying out. Water that covers the floor of the tub, or is dirty and smells, means it isn't draining.
How much does it cost to fix a dishwasher that won't drain?
Often nothing, because cleaning the filter, the air gap and the disposal inlet fixes most cases. If a part has failed, a new drain hose typically costs $150 to $300 installed and a drain pump $200 to $450. On a dishwasher more than about 10 years old, weigh a pump replacement against a new unit.
Get an answer for your house
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Diagnose it from a photoFirst diagnosis free. No account needed.
General guidance, not a substitute for a licensed professional who can see the problem in person. If you smell gas, see sparks or smoke, or anyone is hurt, leave the area and call 911.