Dishwasher Not Draining All the Way: Troubleshooting Guide
Quick answer
Check the drain filter and drain hose for clogs. Ensure the dishwasher is level and the drain pump is functioning. If issues persist, inspect the drain valve or call a professional.
Confirm the symptom
- Water remains in the dishwasher after the cycle ends.
- Dishes are not clean due to standing water.
- Dishwasher makes unusual noises during the drain cycle.
- Error codes related to draining appear on the control panel.
Tools and prep
- screwdriver set — for removing panels and accessing internal components
- bucket — for catching water during repairs
- flashlight — for illuminating dark areas under the sink
- towel — for cleaning up spills and drying components
- plumber's snake — for clearing clogs in drain hoses
- multimeter — for testing electrical components
- work gloves — for protecting hands during repairs
- shop vac — for removing water from the dishwasher
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Prep & safety
- Unplug the dishwasher or turn off the circuit breaker to ensure safety.
- Allow the dishwasher to cool down if it was recently in use.
- Place towels around the dishwasher to catch any water spills.
- Clear the area around the dishwasher for easy access to components.
Step-by-step troubleshooting
Check the Drain Filter
Do: Locate the drain filter at the back of the dishwasher's bottom rack. Remove it by turning it counterclockwise.
Observe: Look for food particles, debris, or other obstructions.
Means: Clogged filter prevents proper draining.
Next: Clean the filter and reassemble, then run a test cycle.
Inspect the Drain Hose
Do: Disconnect the drain hose from the dishwasher and the sink's drainpipe.
Observe: Check for kinks, clogs, or damage in the hose.
Means: A blocked or damaged hose can impede water flow.
Next: Clear any obstructions or replace the hose if necessary.
Check the Air Gap
Do: Locate the air gap on the kitchen counter or sink. Remove the cap and check for clogs.
Observe: Look for debris or food particles inside the air gap.
Means: A clogged air gap can cause draining issues.
Next: Clean the air gap and test the dishwasher.
Examine the Drain Pump
Do: Access the drain pump, usually located at the bottom of the dishwasher.
Observe: Check for debris or damage to the pump impeller.
Means: A faulty pump can prevent water from draining.
Next: Clear any obstructions or replace the pump if needed.
Test the Drain Valve
Do: Locate the drain valve, typically near the drain pump.
Observe: Use a multimeter to test for continuity. The valve should open and close properly.
Means: A malfunctioning drain valve can cause draining problems.
Next: Replace the drain valve if it is faulty.
Check the Float Switch
Do: Find the float switch inside the dishwasher, usually near the drain.
Observe: Ensure the float switch moves freely and is not stuck.
Means: A stuck float switch can prevent the dishwasher from draining.
Next: Free the float switch or replace it if necessary.
Inspect the Check Valve
Do: Locate the check valve, often near the drain pump.
Observe: Ensure the check valve is functioning correctly and not clogged.
Means: A faulty check valve can cause water to flow back into the dishwasher.
Next: Replace the check valve if it is defective.
Verify Leveling
Do: Check if the dishwasher is level using a spirit level.
Observe: Ensure the dishwasher is not tilted or uneven.
Means: An unlevel dishwasher can affect draining.
Next: Adjust the leveling legs and retest the dishwasher.
Common causes table
| Cause | Why | Likelihood | Difficulty | Part often needed |
|---|---|---|---|---|
| Clogged Drain Filter | Food particles and debris accumulate, blocking water flow. | High | Easy | Drain filter |
| Blocked Drain Hose | Kinks or clogs in the hose prevent proper draining. | Medium | Medium | Drain hose |
| Faulty Drain Pump | The pump fails to push water out, causing drainage issues. | Medium | Medium | Drain pump |
| Malfunctioning Drain Valve | The valve does not open or close properly, affecting drainage. | Medium | Medium | Drain valve |
| Stuck Float Switch | The float switch prevents the dishwasher from draining. | Low | Medium | Float switch |
| Defective Check Valve | The check valve allows water to flow back into the dishwasher. | Low | Medium | Check valve |
| Unlevel Dishwasher | An unlevel dishwasher can cause water to pool and not drain properly. | Medium | Easy | Leveling legs |
Parts matching
When replacing parts, ensure they match the specifications of your dishwasher model.
- Drain filter: Match the size and type (mesh or cylindrical) specific to your dishwasher model.
- Drain hose: Ensure the length and diameter match the original hose.
- Drain pump: Match the voltage, amperage, and impeller type to your dishwasher model.
- Drain valve: Verify the voltage, amperage, and compatibility with your dishwasher model.
- Float switch: Ensure it fits the mounting bracket and is compatible with your dishwasher model.
- Check valve: Match the size and type (flapper or spring-loaded) specific to your dishwasher model.
Consult your dishwasher's user manual or manufacturer's website for exact part numbers and specifications.
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When to call a pro
- If the dishwasher is still not draining after troubleshooting.
- If you are not comfortable working with electrical components.
- If the dishwasher is under warranty and you want to avoid voiding it.
- If the issue is complex and requires specialized tools or knowledge.
- If there are signs of water damage or leaks in the surrounding area.
- If the dishwasher is making unusual noises or emitting strange odors.
FAQ
Why is my dishwasher not draining but the pump is working?
If the pump is working but the dishwasher is not draining, check for clogs in the drain hose, air gap, or drain filter. Ensure the drain valve and check valve are functioning properly.
Can I use a plumber's snake to clear a clog in the dishwasher?
Yes, a plumber's snake can be used to clear clogs in the drain hose or air gap. Insert the snake carefully to avoid damaging the components.
How do I test the drain pump with a multimeter?
Disconnect the pump from the dishwasher and use a multimeter to test for continuity. Set the multimeter to the ohms setting and touch the probes to the pump's terminals. A functioning pump should show continuity.
What should I do if the float switch is stuck?
Try to free the float switch by gently moving it up and down. If it remains stuck, replace the float switch with a new one compatible with your dishwasher model.