How to Fix a Dishwasher Not Draining: 2026 Guide

Finding a pool of stagnant water at the end of a cycle is a common kitchen headache, but knowing how to fix a dishwasher not draining can often save you an expensive service call. While some drainage issues are mechanical, the majority are caused by simple maintenance oversights or plumbing obstructions. This guide ranks solutions from most likely to least likely to help you diagnose the issue efficiently.

5 Common Causes for Dishwasher Drainage Issues

1Clogged Filtration System

Modern 2026 dishwashers utilize high-efficiency fine-mesh filters to trap food particles. If these aren’t cleaned regularly, they become coated in grease and debris, eventually forming a waterproof barrier that prevents the pump from pulling water out of the tub.

Symptoms

• Standing water covers the bottom of the dishwasher tub.
• The dishes are coming out with “grit” or food particles redeposited on them.

Care Plan

1. Remove the bottom rack of the dishwasher.
2. Twist and lift out the cylindrical filter located at the center of the floor.
3. Rinse the filter under warm water, using a soft brush to remove stuck-on grease.
4. Check the sump area (the hole under the filter) for large debris like glass or bones.
5. Reinstall the filter, ensuring it “clicks” or locks back into its original position.

Common Mistakes

• Running the dishwasher without the filter installed, which can lead to a permanent pump failure.
• Using a wire brush that tears the delicate mesh of the filter.

2Obstructed Drain Hose (Kinked or Clogged)

The drain hose carries water from the pump to the sink drain. Because this hose is often flexible plastic, it can become kinked if the dishwasher is pushed too far back, or it can develop a clog where it connects to the garbage disposal.

Symptoms

• The dishwasher hums as if it’s trying to drain but the water level doesn’t drop.
• You see a “Drain Error” code on the 2026 digital display.

Care Plan

1. Inspect the hose under the sink for any visible kinks or sharp bends.
2. Disconnect the hose from the garbage disposal or sink tailpiece (have a bucket ready).
3. Check the end of the hose for a “solid” plug of food waste or grease.
4. Flush the hose with water from a separate tap or use a straightened wire to gently probe for and clear blockages.
5. Ensure the hose has a “high loop” (is fastened higher than the drain) to prevent sink water from flowing back into the dishwasher.

Common Mistakes

• Overlooking a kink that only happens when the dishwasher door is closed or the unit is fully pushed in.
• Forgetting to reinstall the hose clamp securely, leading to a flood under the sink.

3Blocked Air Gap or Garbage Disposal

In many homes, the dishwasher drains through a small chrome cylinder on the sink (the air gap) or directly into the garbage disposal. If the disposal is full of food or the air gap is clogged with a stray piece of plastic, the water has nowhere to go.

Symptoms

• Water spurts out of the chrome air gap onto the countertop.
• The dishwasher only fails to drain after you’ve had a large meal.
• The problem began right after a new garbage disposal installation.

Care Plan

1. Always run your garbage disposal with plenty of water before starting the dishwasher.
2. If you have an air gap, pop off the chrome cover and unscrew the plastic cap.
3. Use a toothpick or small brush to clear any debris from the internal tubes.
4. If you recently installed a new disposal, ensure the “knockout plug” in the dishwasher inlet was removed.
5. Verify that the hose connection to the disposal isn’t blocked by hardened grease.

Common Mistakes

• Assuming the dishwasher is broken when the garbage disposal is simply full of peels.
• Replacing the air gap when it just needed a 30-second cleaning.
• Forgetting to remove the disposal’s dishwasher knockout plug during installation.

4Failed Drain Pump Motor

The drain pump is a small motor that forces water out of the machine. These can fail electrically, or the internal “impeller” (the spinning fins) can be broken or jammed by a hard object like a toothpick or a piece of broken glass.

Symptoms

• A loud grinding or clicking noise when the dishwasher reaches the drain cycle.
• The pump feels hot to the touch or produces a faint burning smell.

Care Plan

1. Access the pump (usually located behind the bottom kickplate).
2. Remove the pump from the housing (with power OFF) and check the impeller for blockages.
3. Use a multimeter to test the pump motor terminals for continuity.
4. If the motor shows no continuity or the impeller is physically broken, the pump must be replaced.
5. Clear any debris from the pump housing before installing the new unit.

Common Mistakes

• Replacing the pump before checking for a simple $0 clog in the hose or filter.
• Touching electrical terminals before ensuring the power is disconnected at the breaker.

5Stuck Check Valve

The check valve is a small rubber or plastic flap that allows water to flow out but prevents dirty sink water from flowing back into the dishwasher. If this valve gets stuck closed, no water can exit; if it gets stuck open, the dishwasher will constantly refill with dirty water.

Symptoms

• The dishwasher pumps out water, but it immediately flows back in when the pump stops.
• Water remains in the bottom even after a manual “Drain” cycle.

Care Plan

1. Locate the check valve (usually inside the drain hose connection at the pump).
2. Remove the valve and inspect it for tears, warping, or debris.
3. Clean the valve and the surrounding housing.
4. If the rubber is brittle or deformed, replace it with a new OEM valve.
5. Reassemble and run a short cycle to confirm the water stays out.

Common Mistakes

• Installing the check valve backward, which will completely block all drainage.
• Misdiagnosing a backflow issue as a pump failure.