Why Is My Dishwasher Not Draining? 7 Common Causes and Fixes

Opening your dishwasher and finding standing water in the bottom can be frustrating.

A dishwasher that won’t drain may have something as simple as a dirty filter or food debris blocking an accessible area. In other cases, the problem may involve the drain hose, garbage disposal connection, drain pump, plumbing, or installation.

Here are 7 common reasons a dishwasher may not drain and the safest things you can check before calling a professional.

Important: Dishwasher designs vary. Always follow your dishwasher owner’s manual before removing filters, covers, hoses, or other components. Do not use chemical drain cleaners in a dishwasher.

1. The Dishwasher Filter Is Dirty

A dirty or clogged filter is one of the first things to check when water remains in the dishwasher.

Depending on your model, the filter may catch:

• Food particles

• Seeds

• Labels

• Grease

• Small pieces of debris

If too much material collects there, drainage and cleaning performance may be affected.

What to Do

First, check your owner’s manual to see whether your dishwasher has a removable filter.

If it does:

1. Turn the dishwasher off.

2. Remove the lower rack.

3. Locate the filter.

4. Remove it according to the manufacturer’s directions.

5. Rinse away food and debris with warm water.

6. Use a soft brush if necessary.

7. Reinstall the filter securely.

Never force a filter that doesn’t release easily.

For detailed filter-cleaning instructions, read our guide How to Clean a Dishwasher Filter: Step-by-Step Guide.

2. Food Debris Is Blocking an Accessible Drainage Area

Food, labels, seeds, broken pieces of plastic, and other debris may collect around the bottom of the dishwasher.

Even if the filter itself is clean, loose debris may interfere with water movement.

What to Do

Empty the dishwasher and remove the lower rack.

Inspect the accessible bottom of the dishwasher for:

• Food scraps

• Paper labels

• Seeds

• Toothpicks

• Pieces of plastic

• Other loose debris

Carefully remove anything you can safely reach.

Be cautious because broken glass or other sharp objects could be present.

Do not reach deeply into pump openings or internal drainage components.

Prevention Tip

Scrape large food scraps from dishes before loading them.

Most dishes do not need to be completely pre-rinsed unless your dishwasher or detergent manufacturer recommends it.

3. The Drain Hose Is Kinked or Restricted

The dishwasher uses a drain hose to carry wastewater away from the appliance.

If the hose becomes sharply bent, pinched, or restricted, the dishwasher may have trouble draining.

What to Check

If the drain hose is visible and safely accessible, look for:

• Sharp bends

• Kinks

• Crushing

• Pinching

• An object pressing against the hose

Do not pull the dishwasher out or disconnect plumbing unless your owner’s manual instructs you to do so and you are comfortable performing the task.

If the hose appears damaged or the blockage is somewhere you cannot safely reach, contact a professional.

4. There Is a Garbage Disposal Connection Problem

In some kitchens, the dishwasher drains through a connection to the garbage disposal.

A problem at this connection may affect dishwasher drainage.

This can sometimes happen after:

• A new dishwasher installation

• A garbage disposal replacement

• A disposal clog

• Changes to sink plumbing

What to Do

If your dishwasher drains through a garbage disposal, make sure the disposal itself is functioning normally.

Follow the disposal and dishwasher manufacturers’ instructions.

If the dishwasher stopped draining after a new garbage disposal was installed, contact the installer or a plumber. The dishwasher connection may not have been set up correctly.

Do not begin disconnecting plumbing simply to investigate the problem.

5. The Air Gap Is Clogged

Some dishwasher installations use an air gap, which is usually a small fitting located near the kitchen faucet.

Its purpose is to help prevent dirty drain water from flowing back into the dishwasher.

Not every kitchen has one.

Signs of a Possible Air-Gap Problem

You may notice:

• Dishwasher water draining slowly

• Water coming from the air gap

• Standing water in the dishwasher

• Visible debris around the air-gap opening

What to Do

If your kitchen has an air gap, consult the dishwasher or air-gap manufacturer’s instructions.

You may be able to remove the outer cap and clean visible debris from an accessible area.

Do not pour random household cleaning mixtures into the air gap.

If the blockage is deeper or requires plumbing disassembly, contact a plumber or appliance professional.

6. The Dishwasher Drain Pump May Have a Problem

The drain pump helps move wastewater out of the dishwasher.

If the pump is blocked, damaged, or malfunctioning, the dishwasher may leave water behind.

Possible signs include:

• Dishwasher won’t drain

• Standing water repeatedly returns

• Humming or buzzing during the drain portion of the cycle

• Grinding or unusual mechanical noises

• Drain-related error codes

What to Do

Start with the basic maintenance steps your owner’s manual recommends, such as checking the filter and accessible debris.

Do not disassemble the pump, remove wiring, or attempt internal electrical repairs.

If the filter is clean and the dishwasher still won’t drain, a qualified appliance technician may need to inspect the pump.

7. There Is a Plumbing or Installation Problem

Sometimes the dishwasher itself is not the source of the problem.

Drainage may be affected by:

• Clogged household plumbing

• Improper drain-hose installation

• Sink drainage problems

• Garbage disposal issues

• Incorrect dishwasher installation

• Backflow from another part of the plumbing system

Signs to Watch For

Consider a plumbing or installation problem if:

• Your sink is also draining slowly.

• Water backs up into the sink.

• Dishwasher water returns after draining.

• The problem began after a dishwasher or garbage disposal installation.

• Multiple kitchen drains are affected.

A plumber or appliance installer may be the best person to diagnose these problems.

What Should You Do If There Is Standing Water in the Dishwasher?

If you see a noticeable pool of water after a cycle:

Step 1: Make Sure the Cycle Finished

Confirm that the dishwasher wasn’t accidentally stopped before the drain portion of the cycle.

Step 2: Turn the Dishwasher Off

Follow your manufacturer’s safety instructions before checking the appliance.

Step 3: Inspect the Filter

If your dishwasher has a user-removable filter, check it for food and debris.

Step 4: Look for Loose Debris

Inspect accessible areas around the bottom of the dishwasher.

Step 5: Check for an Obvious Hose Problem

If the drain hose is visible, look for a clear kink or pinch.

Step 6: Consider the Sink and Garbage Disposal

If those are also having drainage problems, the issue may involve household plumbing.

Step 7: Stop if the Problem Requires Disassembly

If diagnosing the problem requires taking apart the pump, wiring, plumbing, or internal dishwasher components, contact a professional.

What Not to Do When a Dishwasher Won’t Drain

Don’t Pour Chemical Drain Cleaner Into the Dishwasher

Dishwasher drainage systems are not the same as ordinary sink drains.

Chemical drain-opening products may damage appliance components and create additional safety concerns.

Don’t Mix Cleaning Chemicals

Never combine household cleaning products.

Don’t Force the Filter Out

If the filter doesn’t come out the way your manual describes, stop.

Don’t Take Apart the Drain Pump

Pump and electrical repairs are better left to qualified technicians.

Don’t Assume Every Dishwasher Is Built the Same Way

A repair video for another model may show completely different parts and procedures.

Use the instructions for your exact dishwasher.

How to Help Prevent Dishwasher Drainage Problems

A little routine maintenance may help prevent some drainage issues.

• Scrape large food scraps before loading.

• Check your removable filter according to the manufacturer’s schedule.

• Keep the bottom of the dishwasher free of loose debris.

• Load dishes so they don’t block the spray arms.

• Use detergent designed for automatic dishwashers.

• Follow the recommended detergent amount.

• Pay attention to slow drainage before it becomes a complete blockage.

• Address sink or garbage disposal problems promptly.

When to Call a Professional

Contact an appliance technician, plumber, manufacturer, or installer if:

• The dishwasher repeatedly won’t drain.

• Standing water keeps returning.

• You hear grinding, buzzing, or unusual mechanical sounds.

• The dishwasher leaks.

• Drain-related error codes continue.

• The drain hose appears damaged.

• The problem requires removing the dishwasher or taking apart plumbing.

• The drain pump may be faulty.

• Your sink or other drains are also backing up.

• Basic manufacturer-approved troubleshooting doesn’t solve the problem.

Frequently Asked Questions

Why is there water in the bottom of my dishwasher?

A noticeable amount of standing water may be caused by a dirty filter, trapped debris, drain-hose problem, plumbing issue, or mechanical problem.

Check your owner’s manual for the first troubleshooting steps recommended for your model.

Can a dirty dishwasher filter stop it from draining?

A heavily clogged removable filter may contribute to drainage problems on some dishwashers.

However, drainage problems can have other causes as well.

Should I use vinegar and baking soda to unclog my dishwasher?

No household cleaning mixture should be treated as a universal dishwasher drain fix.

Follow your appliance manufacturer’s instructions instead.

Can I put drain cleaner in my dishwasher?

Avoid using chemical drain-opening products in a dishwasher unless your appliance manufacturer specifically instructs you to use a particular product.

Why does my dishwasher drain slowly?

Possible causes include a dirty filter, food debris, a restricted drain hose, air-gap problems, plumbing issues, or a mechanical problem.

Why did my dishwasher stop draining after installing a new garbage disposal?

The dishwasher-to-disposal connection may not have been completed correctly during installation.

Contact the installer or follow the manufacturer’s installation instructions.

Can I fix a dishwasher drain pump myself?

Routine filter and debris cleaning may be appropriate for homeowners, but internal pump or electrical work should generally be handled according to the manufacturer’s service instructions or by a qualified technician.

Why does my dishwasher smell when it won’t drain?

Standing water and trapped food debris can develop unpleasant odors.

Fixing the drainage problem is more important than simply covering the smell with cleaning products.

Final Thoughts

If your dishwasher isn’t draining, start with the easiest and safest areas first.

Check for:

1. A dirty filter

2. Trapped food debris

3. A kinked or restricted drain hose

4. Garbage disposal connection problems

5. A clogged air gap

6. A drain-pump problem

7. Plumbing or installation problems

Many minor drainage problems begin with food debris or a dirty filter, but persistent standing water can also indicate a mechanical or plumbing issue.

If basic maintenance doesn’t solve the problem, stop before disassembling the appliance and contact a qualified professional.