Dishwasher Not Draining? Causes & Fixes Appliance Medic Pro

A dishwasher not draining properly often leaves standing water at the bottom of the tub. At Appliance Medic Pro, this is one of the most frequent dishwasher service calls we receive, and in many cases, the issue is caused by simple blockages rather than a major failure.

Addressing the problem early prevents odors, leaks, and pump damage.

Why Is My Dishwasher Not Draining?

From real technician experience, dishwashers usually fail to drain due to clogs, pump issues, or drainage hose problems. Knowing when the water appears—after the wash or at the end of the cycle—helps narrow down the cause.

Common Reasons a Dishwasher Will Not Drain

1. Clogged Filter or Food Debris (Most Common)

We frequently find:

• Food particles

• Grease buildup

• Broken glass fragments

A clogged filter prevents water from exiting the tub.

2. Blocked or Kinked Drain Hose

Drain hoses can:

• Become kinked behind the dishwasher

• Collect grease buildup

• Freeze or crack in colder areas

This stops water from flowing out.

3. Faulty or Jammed Drain Pump

When the pump fails:

• Water stays in the tub

• A humming noise may be heard

• Debris like bones or seeds often jams the impeller

4. Garbage Disposal or Sink Drain Issue

If the dishwasher drains into a disposal:

• A clogged disposal blocks drainage

• New disposals may still have the knockout plug installed

This is a very common installation oversight.

5. Air Gap or Check Valve Blockage

Blocked air gaps or valves:

• Prevent proper draining

• Cause water to back up into the dishwasher

What You Can Safely Check Yourself

Before calling a technician:

✅ Turn offthe  power to the dishwasher
✅ Remove and clean the filter
✅ Check and straighten the drain hose
✅ Run the garbage disposal
✅ Inspect air gap for clogs

❌ Do not run the dishwasher repeatedly with standing water.

When to Call a Professional

Call Appliance Medic Pro if:

• Water remains after cleaning the filter

• The dishwasher makes humming or grinding noises

• The drain pump isn’t working

• Leaks occur during draining

Professional service prevents pump and motor damage.

Dishwasher Drain Repair Cost

Typical repair ranges:

• Filter cleaning or replacement: $80–$150

• Drain hose replacement: $120–$220

• Drain pump replacement: $180–$350

• Check valve or air gap repair: $100–$200

How to Prevent Dishwasher Drain Problems

From technician experience:

• Scrape food off dishes

• Clean the filter monthly

• Run hot water before starting

• Avoid grease-heavy loads

Frequently Asked Questions

Q: Is standing water in the dishwasher dangerous?
A: It can cause odors, bacterial growth, and pump damage.

Q: Why does my dishwasher drain slowly?
A: Partial clogs or hose restrictions are common causes.

Q: Can I use my dishwasher if it won’t drain?
A: No. Continued use can cause leaks and electrical issues.