Quick answer
Turn off the dishwasher and unplug it. Check the drain hose for clogs, clean the filter, and ensure the air gap is clear. If the problem persists, the pump or drain valve may need attention.
Confirm the symptom
- Water remains in the bottom of the dishwasher after cycles
- Dishes are still wet at the end of a cycle
- You hear water sloshing inside after the cycle ends
- Standing water has a foul odor
Tools and prep
- Screwdriver set
- Plunger (small, sink-style)
- Bucket or towel
- Flashlight
- Rubber gloves
- Plumbing snake or wire hanger
- Clean cloth or sponge
- Unplug the dishwasher for safety
Step-by-step troubleshooting
- Check the Drain HoseDo: Locate the drain hose at the back of the dishwasher and inspect for kinks or clogs.Observe: Clogs or kinks in the hoseMeans: Water can't drain properlyNext: Clear the clog with a plumbing snake or straightened wire hanger.
- Clean the Dishwasher FilterDo: Remove the filter at the bottom of the dishwasher and clean it under running water.Observe: Food debris or buildup on the filterMeans: A clogged filter restricts drainageNext: Reinstall the filter and run a test cycle.
- Inspect the Air GapDo: Check the air gap on the countertop for blockages and clean it with a brush or cloth.Observe: Debris or standing water in the air gapMeans: A blocked air gap prevents proper drainageNext: Flush the air gap with water and ensure it's clear.
- Test the Drain PumpDo: Listen for the drain pump to activate during the cycle and check for unusual noises.Observe: No sound or grinding noise from the pumpMeans: The pump may be faultyNext: Check the pump for clogs or replace it if necessary.
- Examine the Drain ValveDo: Inspect the drain valve for debris or damage that might prevent it from opening.Observe: Debris or a stuck valveMeans: The valve is blocking water flowNext: Clean the valve or replace it if damaged.
- Run a Diagnostic CycleDo: Consult the dishwasher manual to run a diagnostic or sanitize cycle to identify issues.Observe: Error codes or continued drainage problemsMeans: The dishwasher may need professional serviceNext: Contact a technician if issues persist.
Common causes
| Cause | Likelihood | Difficulty | Part often needed |
|---|---|---|---|
| Clogged Drain Hose Food particles or debris block the hose, preventing water from exiting. | Common | Easy | None |
| Clogged Filter A dirty filter restricts water flow and causes standing water. | Common | Easy | None |
| Blocked Air Gap Debris in the air gap prevents proper drainage to the sink. | Sometimes | Easy | None |
| Faulty Drain Pump A worn or broken pump can't push water out of the dishwasher. | Sometimes | Medium | Drain Pump |
| Stuck or Damaged Drain Valve A clogged or broken valve stops water from draining. | Sometimes | Medium | Drain Valve |
| Incorrect Installation Improper hose connections or slope can lead to drainage issues. | Rare | Hard | Professional Installation |
| Failed Control Board A malfunctioning control board may not activate the drain pump. | Rare | Hard | Control Board |
Parts matching
Common parts needed for a dishwasher not fully draining include:
- Drain Pump
- Drain Valve
- Air Gap Assembly
- Water Inlet Valve
- Control Board
Always refer to your dishwasher's model-specific manual for accurate part identification and compatibility.
When to call a professional
- You can't locate or access the drain hose or pump
- The drain pump makes loud grinding noises or doesn't activate at all
- You find a broken or damaged control board
- Standing water persists after replacing the drain valve or pump
- You're unsure about electrical components or wiring
- You've tried all steps and the issue remains unresolved
FAQ
Can I use a drain cleaner in my dishwasher?
No, chemical drain cleaners can damage the dishwasher's components. Use a plumbing snake or manual cleaning instead.
How often should I clean the dishwasher filter?
Clean the filter every 1–2 months to prevent clogs and maintain performance.
Why is my dishwasher draining but still leaving water in the bottom?
This could be due to a faulty drain pump or a blocked air gap, even if the hose appears clear.
What if the drain hose is clear but water still doesn't drain?
Check the drain pump and valve for clogs or damage. If they're fine, the issue may be with the control board.
Can a clogged garbage disposal affect my dishwasher drainage?
Yes, if the dishwasher drains into a garbage disposal, a clogged disposal can cause backflow and drainage issues.