Quick answer
First, unplug the dishwasher and check the filter and drain pump for clogs. If water remains after cleaning, inspect the drain hose and air gap. If the pump is damaged or the drain line is blocked, you may need to replace the pump or call a plumber.
Confirm the symptom
- Water remains in the bottom of the dishwasher after a cycle
- Dishes are not fully dry
- Dishwasher emits a foul odor from standing water
- Dishwasher makes gurgling or bubbling sounds during drain cycle
- Water overflows into the floor or sink
Tools and prep
- Screwdriver set
- Plunger or wet/dry vacuum
- Bucket or towels
- Flashlight
- Plumber's snake or wire hanger
- Rubber gloves
- Turn off power to the dishwasher at the circuit breaker
- Shut off the water supply valve if needed
Step-by-step troubleshooting
- Check for Standing Water
Do: Open the dishwasher door and look for water pooled in the bottom.Observe: Water level after cycleMeans: Standing water indicates a drainage issue.Next: Clean the filter
- Clean the Filter
Do: Locate and remove the filter at the bottom of the dishwasher. Clean it with warm water and a brush.Observe: Filter is clogged with food particles or debrisMeans: A clogged filter can prevent proper drainage.Next: Inspect the drain pump
- Inspect the Drain Pump
Do: Access the drain pump (usually at the bottom of the dishwasher) and check for debris or damage.Observe: Pump is clogged or makes unusual noisesMeans: A clogged or faulty pump can prevent water from draining.Next: Clear the drain hose
- Clear the Drain Hose
Do: Disconnect the drain hose from the dishwasher and the sink or disposal. Use a plunger or wet/dry vacuum to clear any blockages.Observe: Water flows freely through the hoseMeans: A clogged drain hose is a common cause of drainage issues.Next: Check the air gap
- Check the Air Gap
Do: Inspect the air gap on the sink for blockages. Clean it with a brush or wire hanger if necessary.Observe: Air gap is clogged or damagedMeans: A clogged air gap can prevent proper drainage.Next: Verify the drain line high loop
- Verify the Drain Line High Loop
Do: Ensure the drain hose has a high loop under the sink to prevent siphoning.Observe: Drain hose is properly loopedMeans: A high loop is necessary for proper drainage.Next: Test the dishwasher
- Test the Dishwasher
Do: Reconnect the power and water supply, then run a test cycle to see if the issue is resolved.Observe: Dishwasher drains completely and dishes are dryMeans: The issue is resolved.Next: Call a professional if the problem persists
Common causes
| Cause | Likelihood | Difficulty | Part often needed |
|---|---|---|---|
| Clogged filter Food particles and debris can accumulate in the filter, blocking water flow. | Common | Easy | Dishwasher filter |
| Clogged drain pump Debris can get trapped in the pump, preventing it from draining water. | Common | Easy–Medium | Dishwasher drain pump |
| Clogged drain hose Food particles or grease can block the drain hose, preventing water from exiting. | Common | Easy | Dishwasher drain hose |
| Clogged air gap Debris can block the air gap, preventing water from draining properly. | Sometimes | Easy | Air gap |
| Improper high loop in drain hose A low drain hose can allow water to siphon back into the dishwasher. | Sometimes | Easy | None |
| Faulty drain pump A damaged or worn-out pump may not function properly. | Sometimes | Medium | Dishwasher drain pump |
| Clogged sink trap A clogged sink trap can prevent water from draining from the dishwasher. | Sometimes | Easy | None |
| Garbage disposal knockout plug not removed If the knockout plug in the garbage disposal is still in place, water cannot drain properly. | Rare | Easy | Garbage disposal knockout plug |
| Faulty water inlet valve A faulty water inlet valve can cause water to not drain properly. | Rare | Medium | Water inlet valve |
| Incorrect installation Improper installation of the drain hose or air gap can lead to drainage issues. | Rare | Medium | None |
Parts matching
If you need to replace parts, look for these common components:
- Dishwasher filter (usually specific to your model)
- Dishwasher drain pump (check compatibility with your model)
- Dishwasher drain hose (ensure correct length and diameter)
- Air gap unit (if applicable)
- Garbage disposal knockout plug (if applicable)
Always refer to your dishwasher's manual for specific part numbers and installation instructions.
Disclosure: We may earn a commission from qualifying purchases via affiliate links. Learn more.
When to call a professional
- If the dishwasher still does not drain after cleaning all components
- If the drain pump is damaged and you are unsure how to replace it
- If you suspect a major blockage in the plumbing system
- If the dishwasher is under warranty and you don't want to risk voiding it
- If you are uncomfortable working with electrical components
FAQ
How often should I clean my dishwasher filter?
Clean the filter every 1–2 months to prevent clogs and maintain proper drainage.
Can a clogged air gap cause my dishwasher to not drain?
Yes, a clogged air gap can prevent water from draining properly, leading to standing water in the dishwasher.
What is a high loop in a drain hose?
A high loop is a bend in the drain hose that prevents water from siphoning back into the dishwasher.
Why is my dishwasher making a gurgling noise during the drain cycle?
A gurgling noise often indicates a blockage in the drain hose or air gap.
Can a faulty water inlet valve cause drainage issues?
A faulty water inlet valve typically causes water supply issues, not drainage problems. However, in rare cases, it can affect the overall water balance in the dishwasher.