Dishwasher Not Draining: Troubleshooting Guide
Quick answer
First, check if the drain hose is kinked or clogged. Ensure the air gap or drain line is clear. If these are fine, inspect the drain pump for blockages.
Confirm the symptom
- Dishwasher leaves standing water after cycle
- Dishes are not clean due to poor drainage
- Drain cycle is noisy or takes longer than usual
- Error code related to draining appears on display
Tools and prep
- Screwdriver Phillips — To remove dishwasher panels and access internal components.
- Pliers
- Flashlight
- Bucket
- Shop vacuum
- Towel
- Multimeter
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Prep & safety
- Ensure the dishwasher is empty and unplugged from the power source.
- Turn off the water supply to the dishwasher.
- Clear the area around the dishwasher for easy access.
- Have a towel and bucket ready to catch any water that may spill.
Step-by-step troubleshooting
Check the Drain Hose
Do: Locate the drain hose at the back of the dishwasher.
Observe: Look for any kinks, blockages, or damage.
Means: Straighten any kinks and clear any blockages.
Next: Check the air gap or drain line.
Inspect the Air Gap or Drain Line
Do: Locate the air gap on the countertop or the drain line under the sink.
Observe: Check for clogs or blockages.
Means: Clear any debris using a screwdriver or pliers.
Next: Check the drain pump.
Check the Drain Pump
Do: Access the drain pump, usually located at the bottom of the dishwasher.
Observe: Look for any blockages or damage.
Means: Clear any debris and ensure the pump spins freely.
Next: Test the drain pump.
Test the Drain Pump
Do: Use a multimeter to check for continuity in the drain pump.
Observe: Ensure the pump is functioning correctly.
Means: If the pump is faulty, replace it.
Next: Inspect the drain filter.
Inspect the Drain Filter
Do: Locate the drain filter at the bottom of the dishwasher.
Observe: Check for any clogs or blockages.
Means: Clean the filter thoroughly.
Next: Check the drain valve.
Check the Drain Valve
Do: Access the drain valve, usually located near the drain pump.
Observe: Ensure the valve is not stuck or damaged.
Means: If the valve is faulty, replace it.
Next: Inspect the check valve.
Inspect the Check Valve
Do: Locate the check valve in the drain hose.
Observe: Ensure the valve is functioning correctly.
Means: If the valve is faulty, replace it.
Next: Check the motor and control board.
Check the Motor and Control Board
Do: Access the motor and control board.
Observe: Look for any signs of damage or malfunction.
Means: If necessary, replace the motor or control board.
Next: Test the dishwasher.
Test the Dishwasher
Do: Reassemble the dishwasher and run a test cycle.
Observe: Ensure the dishwasher drains properly.
Means: If the problem persists, consult a professional.
Next: None.
Common causes table
| Cause | Why | Likelihood | Difficulty | Part often needed |
|---|---|---|---|---|
| Clogged Drain Hose | Food particles or debris can block the hose. | High | Easy | None |
| Blocked Air Gap or Drain Line | Debris can accumulate and cause blockages. | High | Easy | None |
| Faulty Drain Pump | The pump may be clogged or worn out. | Medium | Moderate | Drain pump |
| Dirty Drain Filter | A clogged filter can restrict water flow. | Medium | Easy | None |
| Faulty Drain Valve | The valve may be stuck or damaged. | Medium | Moderate | Drain valve |
| Faulty Check Valve | The valve may be malfunctioning. | Low | Moderate | Check valve |
| Motor or Control Board Issues | Electrical problems can affect draining. | Low | Hard | Motor or control board |
Parts matching
When replacing parts, ensure they match your dishwasher's specifications.
- Drain pump: Match the model number and voltage of your dishwasher.
- Drain valve: Ensure it fits the make and model of your dishwasher.
- Check valve: Match the size and type required for your dishwasher.
- Motor: Ensure it is compatible with your dishwasher's specifications.
- Control board: Match the model number and voltage of your dishwasher.
Consult your dishwasher's manual for specific part numbers and compatibility.
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When to call a pro
- If the dishwasher is still not draining after troubleshooting.
- If you suspect a major component failure, like the motor or control board.
- If you are not comfortable performing the repairs yourself.
- If the dishwasher is under warranty.
- If there are signs of water damage or leaks.
- If you encounter any electrical issues.
FAQ
Why is my dishwasher not draining?
Common causes include clogged drain hoses, blocked air gaps, faulty drain pumps, or dirty drain filters.
How do I clean the drain filter?
Locate the filter at the bottom of the dishwasher, remove it, and clean it thoroughly under running water.
What should I do if the drain pump is faulty?
If the drain pump is faulty, it will need to be replaced. Ensure you get the correct model for your dishwasher.
Can I use a plunger to unclog the drain hose?
Yes, you can use a plunger to try and dislodge any blockages in the drain hose. Ensure the dishwasher is empty and unplugged first.