Dishwasher Not Draining: Step-by-Step Troubleshooting

Water remaining in the dishwasher after a cycle indicates a drainage problem. This guide helps identify and resolve common causes.

Before You Begin

Safety First

• Never work on a dishwasher with power on
• Unplug or turn off breaker
• Have towels ready for water

Normal vs Abnormal

Normal: Small amount of water in sump area helps maintain pump seals.

Abnormal: Standing water covering bottom, water not receding, visible dirty water.

Troubleshooting Steps

Step 1: Check the Garbage Disposal

If dishwasher drains to disposal:

Run disposal before dishwasher cycle

Clear disposal of debris

New disposal? Check knockout plug removed

Step 2: Inspect the Drain Hose

Check for:

Kinks in the hose

Crushed sections

Clogs at connection points

High loop verification:

Hose should loop up near countertop

Prevents backflow from drain

Air gap if installed should be clear

Step 3: Clean the Filter

Most dishwashers have filters:

Locate filter assembly (bottom of tub)

Twist to unlock and remove

Clean under running water

Use brush for stubborn debris

Reinstall securely

Premium brands (Miele, Bosch):

Multiple filter components

Regular cleaning essential

Check manual for specifics

Step 4: Clear the Drain Sump

In the bottom of the dishwasher:

Remove lower rack

Remove filters

Check sump area for debris

Remove any food particles, glass, or objects

Step 5: Test the Drain Pump

Listen during drain cycle:

Should hear pump running

Humming without draining suggests obstruction

No sound may indicate pump failure

Common Causes by Symptom

Water Drains Slowly

• Partial clog in drain hose
• Dirty filters
• Buildup in sump area

Water Never Drains

• Complete blockage
• Drain pump failure
• Control board issue

Drains Then Refills

• Faulty check valve
• Drain hose position issue
• Disposal connection problem

When to Call for Service

• Pump not running
• After clearing visible obstructions
• Electronic error codes displayed
• Repeated occurrence after cleaning
• Suspected pump or motor failure

Prevention Tips

• Scrape dishes before loading
• Clean filters monthly
• Run disposal before dishwasher
• Use appropriate detergent amounts
• Run hot water before starting cycle