Why is my dishwasher not draining completely after cycle?

Why is my dishwasher not draining completely after cycle

If you’ve noticed that your dishwasher is not draining completely after a cycle, it can be frustrating. There are several reasons why this can happen. In this article, we will explore the common causes of dishwasher drainage issues and provide troubleshooting tips to help you identify and resolve the problem.

Key Takeaways:

  • A dishwasher not draining after a cycle can be caused by several factors.
  • Checking for a clogged drain hose, blocked air gap, or faulty drain pump can help identify the root cause of the issue.
  • Proper loading, detergent usage, and water pressure can also affect dishwasher drainage performance.
  • Regular cleaning and maintenance of your dishwasher can reduce the likelihood of drainage issues.
  • If you have tried troubleshooting and the issue persists, it may be time to consult a professional technician.

Clogged Drain Hose

If your dishwasher is not draining properly, a clogged drain hose may be the cause. The drain hose is responsible for carrying wastewater out of the dishwasher and into the garbage disposal or drain. When it becomes obstructed, water can back up into the dishwasher, leaving dirty dishes and standing water.

To check for a clog, remove the drain hose from the garbage disposal or drain and inspect it for any blockages. You can use a long, thin object such as a coat hanger or pipe cleaner to dislodge any debris. Alternatively, you can run water through the hose to flush out any potential clogs.

If the drain hose is too damaged or clogged to repair, you may need to replace it altogether. Be sure to choose a hose that is compatible with your dishwasher model.

Here’s a table summarizing the common causes and solutions for a clogged dishwasher drain hose:

Causes Solutions
The hose is kinked or incorrectly installed Adjust the hose so that it is not obstructed
The hose is cracked or damaged Replace the drain hose with a new one
The hose is clogged with debris Remove the blockage using a long, thin object or by running water through the hose

By following these steps, you can resolve any issues related to a clogged dishwasher drain hose and ensure that your dishwasher drains effectively after every cycle.

Blocked Air Gap

If your dishwasher is not draining completely after a cycle, it could be due to a blocked air gap. This component is important as it prevents wastewater from flowing back into your dishwasher, ensuring clean dishes every time.

An air gap is a small device typically located on the countertop beside your sink or, less commonly, installed in the sink itself. It’s connected to the dishwasher’s drain line and the sink’s drain line, creating a small gap that allows air to flow in and prevents siphoning.

If the air gap becomes obstructed, it can impede the flow of wastewater from your dishwasher and lead to incomplete draining. To check if the air gap is blocked, remove the cover and visually inspect it for any debris or buildup.

Tip: You can also try blowing into the air gap to see if air flows freely through it.

If you notice any debris or buildup in the air gap, it’s important to clean it properly to ensure proper drainage. To do so, follow these steps:

  1. Remove the cover from the air gap and unscrew the plastic cap from the top of the air gap.
  2. Clean out any debris or buildup from the air gap and cap using a small brush, such as a toothbrush.
  3. Rinse the parts thoroughly with warm water and reassemble the air gap.

After cleaning the air gap, run another cycle to see if the drainage issue has been resolved. If not, you may need to explore additional troubleshooting options.

Clogged Drain Pump

If your dishwasher is still not draining after checking the drain hose and air gap, the issue may be with the drain pump. The drain pump is responsible for removing water from the dishwasher during the drain cycle.

A malfunctioning drain pump can cause the dishwasher to retain water after the cycle has been completed. The pump motor may have stopped working, or there could be debris blocking the impeller, which is responsible for pumping out the water.

To check if the drain pump is the issue, you can conduct a quick visual inspection. Refer to the manufacturer’s manual to locate the drain pump on your dishwasher. Ensure that the power supply is disconnected before inspecting the pump.

If you notice any debris or foreign objects obstructing the impeller, carefully remove them with pliers or tweezers. Avoid damaging the impeller or the pump housing. Reconnect the power supply and run a short cycle to check if the issue has been resolved.

If the drain pump is still not functioning correctly after cleaning, it may need to be replaced. Refer to the manufacturer’s manual for guidance on replacing the pump.

Clogged Filter or Drain Basket

A clogged filter or drain basket can restrict water flow and prevent your dishwasher from draining properly. These components are usually located near the bottom of the machine. Over time, debris such as food particles and grease can accumulate and block the filter or drain basket, leading to a buildup of water in the dishwasher.

To check for a clog in the filter or drain basket, follow these steps:

  1. Turn off the power to the dishwasher and open the door
  2. Locate the filter and drain basket and remove them from the dishwasher
  3. Clean the filter and drain basket with warm water and a soft brush to remove any debris or buildup
  4. Reinstall the filter and drain basket back into the dishwasher

Regular cleaning of the filter and drain basket can prevent clogs and ensure proper drainage. We recommend cleaning them at least once a month, or more often if your dishwasher gets heavy use.

Improper Installation or Plumbing Issues

If you have recently installed a new dishwasher or moved your appliance, improper installation could be the cause of your drainage issues. Similarly, plumbing problems such as a clogged sink or drain can also impact your dishwasher’s ability to drain completely after a cycle.

To ensure your dishwasher is installed correctly, refer to the manufacturer’s instructions and make sure all connections are secure and the drain hose is properly attached. It’s also important to check that the drain hose is not kinked, as this can impede water flow and affect drainage.

If you suspect a plumbing issue is causing problems with your dishwasher’s drainage, it’s best to consult a professional plumber to assess the problem and make any necessary dishwasher repairs. You can also check for localized plumbing issues such as a clogged sink or drain, and ensure these are resolved to improve your dishwasher’s performance.

Common installation mistakes when installing a dishwasher

Here are some common mistakes to avoid when installing a dishwasher:

  • Not leveling the dishwasher
  • Incorrectly routing the drain hose
  • Installing the dishwasher too tightly
  • Failure to clean the dishwasher inlet screen
  • Inadequate clearance under the countertop

Plumbing problems that can affect dishwasher drainage performance

Plumbing Problem Solution
A clogged sink or drain Clean the sink or drain to remove any blockages
Inadequate air gap Check the air gap to ensure it is properly installed and not obstructed
Backflow prevention device Check the device to ensure it is not clogged or malfunctioning
Plumbing vent blockage Clear any blockages in the plumbing vent to restore proper drainage

Insufficient Water Pressure

Insufficient water pressure can lead to your dishwasher not draining completely after a cycle. The correct water pressure ensures optimal performance and helps the dishwasher to remove food particles and other debris from dishes effectively.

If you have noticed that your dishwasher is not draining completely, low water pressure could be the reason. The following factors can contribute to low water pressure:

  • Blocked or kinked water supply line.
  • Clogged water inlet valve.
  • Malfunctioning water pump.
  • Low water pressure in the supply line.

To solve this issue, check the water supply line for any kinks or blockages. Make sure that the water inlet valve is not clogged with debris and is functioning properly. If you have ruled out these reasons, try increasing the water pressure in your home. If the issue persists, it may be due to a malfunctioning water pump.

Proper water pressure is essential for the effective functioning of your dishwasher. Low water pressure can lead to incomplete drainage and other related issues as well. By addressing this issue, you can ensure that your dishwasher drains completely after every cycle.

Overloading or Improper Loading

Improper loading or overloading of dishes in your dishwasher can contribute to drainage issues.

It’s essential to ensure that you load your dishwasher correctly to avoid blocking the drainage system.

Proper Dish Placement

When loading your dishwasher, ensure that you space out your dishes so that the water and detergent can reach every side properly. Overcrowding the dishwasher can prevent water and detergent from reaching all the dishes, leaving them dirty and contributing to drainage problems.

Ensure that you angle your bowls and plates downwards towards the spray arm to allow water to drain off quickly.

It’s also important to avoid stacking dishes too high, particularly large plates and bowls. This can prevent water from reaching the upper dishes and cause drainage problems.

Preventing Overloading

You can prevent overloading by running multiple cycles instead of overloading the dishwasher with too many dishes. This will give you a chance to clean all the dishes without causing drainage problems.

If you have a larger family or frequently host guests, consider purchasing a larger dishwasher to accommodate your needs properly.

By following these tips, you can ensure that your dishwasher drains correctly after every cycle, avoiding any inconvenience and potential damage to your appliance.

Detergent or Rinse Aid Buildup

Over time, detergent and rinse aid can build up in your dishwasher and affect its performance, leading to drainage issues. This buildup can occur due to excessive detergent or rinse aid usage, improper loading of the dispenser, or infrequent cleaning of the dishwasher.

To prevent detergent and rinse aid buildup, it’s essential to use the recommended amount of detergent and rinse aid and ensure that they are loaded correctly in the dispenser. Additionally, be sure to clean the dispenser regularly to prevent any residue from accumulating.

If you notice a buildup in your dishwasher, you can clean it using a dishwasher cleaner or a natural solution of vinegar and baking soda. Simply remove any dishes from the dishwasher, place the cleaner or solution in the detergent dispenser, and run the dishwasher on a hot cycle.

Regular cleaning of your dishwasher can help prevent buildup and keep it functioning optimally. By following these simple steps, you can ensure that your dishwasher provides you with sparkling dishes and effective drainage after every cycle.


If you’re experiencing issues with your dishwasher not draining completely after a cycle, don’t panic! There are several possible reasons for this and many solutions you can try.


To recap, we covered common reasons for drainage problems in your dishwasher, including:

  • Clogged drain hose
  • Blocked air gap
  • Faulty drain pump
  • A clogged filter or drain basket
  • Improper installation or plumbing issues
  • Insufficient water pressure
  • Overloading or improper loading
  • Detergent or rinse aid buildup

By following the troubleshooting tips outlined in each section, you should be able to identify and resolve the issue with your dishwasher’s drainage. Remember, it’s important to properly maintain your dishwasher and ensure it’s installed correctly to avoid future problems.

Expert Help

If you’ve tried all the troubleshooting tips and still can’t resolve the issue, it may be time to call in a professional. Don’t hesitate to seek expert help if you need it.

We hope this guide has been helpful in troubleshooting your dishwasher’s drainage problems. Happy dishwashing!

Max Appliance Repair

Written by Max | An appliance repair technician with more than 15 years experience in appliance repair services in Toronto and the GTA.

Disclaimer: This post "Why is my dishwasher not draining completely after cycle?" is for information purposes only. If you need specific help, please contact Max Appliance Repair at https://maxfix.ca/contact/.