Standing water at the bottom of the dishwasher is a sign that it is not draining. That is often caused by a clogged filter or drain hose, or jammed drain pump impellers. It could also be caused by a kinked or poorly installed drain hose or a clogged garbage disposal/sink drain line.
Here is a brief summary of this post:
- Clogged Filter or Drain: Accumulated debris and food particles can clog the dishwasher’s filter or drain, preventing water from draining properly.
- Blocked Drain Hose: A blocked or kinked drain hose can restrict water flow, leading to standing water in the dishwasher.
- Garbage Disposal Connection: If the dishwasher drain hose is connected to a garbage disposal unit, a clog or blockage in the disposal can impede water drainage.
- Faulty Drain Pump: A malfunctioning or worn-out drain pump may be unable to remove water effectively, causing it to accumulate in the dishwasher.
- Improper Dish Loading: Incorrect loading of dishes, obstructing the spray arms or impeding water circulation, can result in standing water.
- Detergent Residue: Excessive or incorrect detergent usage can create excessive suds and inhibit proper drainage.
- Clean the Filter: Regularly clean the dishwasher’s filter to remove debris and food particles. Refer to the dishwasher manual for filter removal and cleaning instructions.
- Check the Drain Hose: Inspect the drain hose for kinks, blockages, or improper installation. Straighten out kinks and clear any clogs.
- Garbage Disposal Inspection: If the dishwasher is connected to a garbage disposal, verify that it’s clear of any clogs or obstructions. Run the disposal to ensure it’s functioning properly.
- Test the Drain Pump: Test the dishwasher’s drain pump by running a drain cycle or using a diagnostic mode if available. If the pump is malfunctioning, it may need repair or replacement by a technician.
- Proper Dish Loading: Arrange dishes and utensils in the dishwasher to allow unobstructed water flow and ensure that the spray arms can rotate freely.
- Adjust Detergent Usage: Use the recommended type and amount of dishwasher detergent. Avoid overloading the detergent dispenser, which can cause excessive suds.
- Regular Maintenance: Routinely perform maintenance tasks such as cleaning the spray arms, inspecting gaskets and seals, and checking for loose or damaged components.
- Professional Assistance: If the problem persists or if you’re uncertain about the cause, consult a professional dishwasher repair technician to diagnose and fix the issue.
How Do You Fix a Dishwasher that is not Draining?
To troubleshoot a dishwasher that is not draining, you need to first determine if the problem is isolated in the dishwasher or if it is affecting several fixtures. As I have already mentioned, the dishwasher, garbage disposal and sink share the same drainpipe.
Turn on the cold water on the kitchen faucet and start the garbage disposal. Let it run for like a minute.
Meanwhile, check if water is backing up through the garbage disposal itself or through the dishwasher. If there is water backing up through the garbage disposal or dishwasher turn off the faucet immediately and stop the disposal.
If you do not have a garbage disposal, turn on water on your kitchen sink faucet and again let it run for like a minute. Check if water will start to back up through the sink drain or dishwasher.
When you run a garbage disposal or try to drain a sink and the water backs up through the sink drain or dishwasher, you are dealing with a clogged kitchen sink drain line or garbage disposal. Unclogging any of the 2 will most likely fix the problem.
On the other hand, if both the garbage disposal and kitchen sink drain line are draining normally and you have standing water at the base of your dishwasher, you are dealing with a clogged filter, jammed drain pump impellers or a clogged/kinked drain hose.
If you have a dishwasher air gap and your dishwasher is not draining, the problem is within the dishwasher and the drain hose up to the air gap. If the clog was beyond that, you would notice water leaking from the air gap and entering the sink.
How to Unclog a Dishwasher
When unclogging a dishwasher that is not draining, the initial challenge is how to get rid of the standing water. The following are the steps to follow when unclogging a garbage disposal that is not draining:
1. Drain the Standing water
Caution: Turn off your dishwasher before starting to work on it. It will most likely be hardwired and you will need to turn it off at the circuit breaker.
Before draining the standing water, start by removing the lower dish rack. That will give you enough space to work on the dishwasher.
There are several ways you can use to drain water from a dishwasher that is not draining. An easy and efficient method is to soak it up using a sponge and squeeze it out into the sink or a bucket.
You can also use a wet vac and suck up all the water. Choose the method that best suits you.
2. Clean the Filter
A dishwasher comes with a filter which prevents food scraps from draining out with the wastewater and clogging the pump or drain hose. In the course of doing its job, the dishwasher filter can get badly clogged, restricting the flow of water and hence the standing water at the bottom of the dishwasher.
Usually, such a clog will not happen in an instance. It takes time and in the first few days you will notice that the dishwasher will drain slowly before graduating to a full clog.
Depending on the type of dishwasher you have, the filter in your dishwasher will look different from other models. They however all work the same.
If the lower spraying arm stands in your way, you can remove it as well. In most cases that will not be necessary.
To remove most dishwasher filters (Bosch dishwasher for instance), you will only need to turn it counterclockwise a little then lift off. If your dishwasher filter is secured using 2 screws, remove them using a screwdriver.
Carefully inspect the filter for clogs. Clean it with running water in the sink using an old toothbrush to make sure that all those tiny pores are fully opened.
When your filter is sufficiently cleaned, put it back and run a short cycle to see if the problem has been resolved. You may however opt not to run the dishwasher until you have checked all potential sources of clogs.
2. Check the Pump Drain Impellers
After wastewater goes through the filter, it is sent to the drain hose by a drain pump located at the bottom of the dishwasher.
The drain pump just like other pumps has impellers which spin at a high speed and in the process force water out of the dishwasher. Sometimes, product labels, brush bristles and other tiny objects can escape through the filter and jam the impellers.
When a drain pump impellers are jammed, they cannot spin and when they don’t spin it means wastewater cannot drain out of the dishwasher. This is could be the reason you have standing water at the bottom of your dishwasher.
To access your drain pump impellers, you will need to have removed your dishwasher filter. Inside the filter sump (where water enters the drain pump), you will see a small plastic cover. That is the cover that conceals the drain pump impellers.
Use a flathead screwdriver or just your hand to remove the cover to reveal the impellers. You may need a flashlight to properly see them.
Check if there is anything jamming the impellers and preventing them from spinning. Fish the clogs out and try to manually spin the impellers using the screwdriver.
When the impellers start to spin freely, put back the cover and the filter. Again, you can test the dishwasher at this time or wait until you have checked other areas.
If your dishwasher model does not have the cover near the filter, another way to check the impellers is by disconnecting the drain hose from the drain pump as shown in the point below.
3. Unclog the Drain Hose.
A dishwasher drain hose carries wastewater from the drain pump and is connected to the garbage disposal or directly to the kitchen sink drain line.
Depending on how your dishwasher drain hose is plumbed, it will either be connected to an air gap or it will be looped from underneath the counter.
An air gap’s main function is to prevent wastewater from siphoning back to the dishwasher in case of a clogged garbage disposal or sink drain line. The main challenge with a high looped dishwasher drain hose (without an air gap) is the problem solved by the air gap.
Kinked drain hoses can also prevent the dishwasher from draining, resulting in water pooling at the bottom of the dishwasher.
It is not uncommon for grease, sludge and excess detergents to coalesce and form a clog inside the dishwasher drain hose. That is especially the case when you have a corrugated drain hose.
This is how to check if your dishwasher drain hose is clogged.
- Remove the lower dishwasher access panel. It is usually secured using 2 or sometimes 4 screws. Put it aside.
- With the panel out of the way, you can see where the drain hose is connected to the drain pump. Use a pair of pliers to disconnect the drain hose from the pump. Before disconnecting, place a towel or sponge underneath the connection to soak up any water that may drain out.
- Check inside the drain pump if there is anything jamming the impellers. Remove the clogs until the impellers are spinning freely.
- To try and unclogging the drain hose, put the end in your mouth and blow on it forcefully. If there is a light clog between it and the garbage disposal, you should be able to dislodge it.
- Disconnect the drain hose where it is connected to the drain line or garbage disposal and check for clogs there as well. Scrape off gunk from the inlet using a screwdriver.
- Connect the drain hose back to the drain pump and garbage disposal and run a short cycle. See if it will start to drain properly.
Another way to unclog a dishwasher drain hose is to remove it entirely and snake it using a drain snake it or forcing a thinner hose through it. Soaking it using a baking soda and vinegar solution will also help break down the grease and gunk inside.
New Dishwasher Not Draining?
If you have a new dishwasher that is not draining, a clog is highly unlikely. The problem is usually caused by a plug inside the garbage disposal inlet.
Garbage disposals are sold with an inlet to allow you connect your dishwasher. Seeing that not everyone will need a dishwasher, the inlet is usually plugged to prevent water from leaking when the garbage disposal is running.
When installing a garbage disposal, you are supposed to remove the plug by knocking it out. If you don’t, there will be no way for wastewater to drain out of your dishwasher and will instead pool at the bottom.
Here is how to fix the problem:
- Turn off both the dishwasher and the garbage disposal.
- Disconnect the drain hose from the garbage disposal. Have a pan or small container nearby to drain the water already inside the drain hose.
- Stick a screwdriver inside the dishwasher inlet on the garbage disposal to check if the plug is there.
- If indeed the knockout plug is there, use a hammer to gently tap on the screw driver and knock out the plug.
- Fish the plug out of the garbage disposal.
- Connect the drain hose back to the garbage disposal.
It is also important to make sure that the drain hose has no kinks and that it is looped nicely underneath the counter to prevent water from siphoning back to the dishwasher.
To prevent constant clogs by your dishwasher, rinse off dishes before loading them. It is also good to clean the dishwasher using baking soda and vinegar from time to time. A cup of vinegar and ½ cup baking soda is sufficient.
Apart from breaking down gunk, baking soda and vinegar will also get rid of bad smells from your dishwasher.
And basically that is how to fix a dishwasher that is not draining.