Dishwasher Not Draining

I’ve had a few issues with dishwashers over the years and I have quite a bit of experience repairing them myself. Although the dishwashers I’ve had generally work perfectly fine, I recently had an issue where the water was draining from the bottom of the dishwasher. I looked into what causes this issue and here’s how to fix it.

It’s most commonly caused by something being stuck in the screens at the base of the dishwasher. There is a filter that catches food particles that can become clogged, and should be cleared. Also, the hoses that lead out from the dishwasher can be blocked and need to be inspected and cleared.

The good news is the most common issue is the easiest to fix but, there are also a few other steps that are too difficult. However, you may decide it’s easier to have a repair technician or someone with more experience fix it for you. In either case below I’ll explain step by step how to fix these issues from the easiest fix to the hardest.

Dishwasher Not Draining

During the wash cycle water is sprayed over the dishes, and drains out at the bottom of the dishwasher, into the waste water, or a garbage disposal unit. Along the way the water can be clogged, and the blockage needs to be cleared. Here’s where blockages can occur, and how to inspect them.

There is a screen at the base of the dishwasher that filters the water to limit blockages. It can be clogged with food particles, and needs to be rinsed out and cleared. A part of crockery can also break off, and pieces of food can get stuck in the hoses and needs to be cleared.

Clearing the hoses is a bit more difficult to do, so it’s best to start with clearing the screens and filter at the base of the dishwasher to see if this solves the issue first. A dishwasher should also be cleaned using a special tablet once a month or so, I’ll cover that as well as, step by step instructions for how to get your dishwasher to drain again.

1. Inspect and clean the screens and filter at the base of the dishwasher

Every dishwasher is slightly different, but at the bottom of the dishwasher there is a hole where the water drains out and gets pumped into the garbage disposal unit, or goes into the waste water lines.

This hole is usually lower than the base of the dishwasher, and above it there is a fine screen, as well as a filter below that. Both of which can become clogged with food debris. Simply pulling the screen and the filter out, and then rinsing them off, and rubbing it with your hand can remove most of it.

The screen is typically made of hard plastic which can be scrubbed with a brush used to clean the dishes manually. Or, another plastic bristle brush. Don’t use a steel wool or a metal brush as it can scratch the plastic.

The filter has a clothlike fabric that is very fine. A brush is too harsh and can damage the fibers. The mesh is too fine to trap food in it, and simply collects chunks of food. So, it can be emptied and then rinsed off. And rubbed with your fingers if any food is stuck to the sides.

Each dishwasher is slightly different so exactly how to clean can vary a little bit. If yours doesn’t look like that shown in the video above then refer to the owners manual for your dishwasher to see how to clean the filters.

2. Clean the dishwasher using a specially design tablets by affresh®

Many of the top dishwasher manufacturers such as Whirlpool, and Kitchenaid recommend cleaning your dishwasher using affresh® tablets. Not only will it help to clear any clogs, and can potentially fix the draining issue, it also removes any bad odours.

Generally, you run your dishwasher on empty with one tablet where you put the detergent. And another one in the bottom of the dishwasher. It’s recommended to do it once a month. But, depending on how often or how little you use your dishwasher you can adjust how often you clean it accordingly.

That’s it for the easy steps, hopefully, that has fixed the drainage issue. The next steps involve using a screwdriver and removing hoses underneath the dishwasher. As well as, where the dishwasher connects to your waste disposer. But, not all homes have a waste disposal unit in the sink.

It can be a bit difficult if you’ve never worked with a screwdriver so you may need to have someone with DIY skills help you. You also need to bend down and work very close to the floor, which may be difficult for some people depending on your level of mobility. So, feel free to have a repair technician take over from here, or ask help from a family member, or friend to do the remaining steps.

3. Reset the motherboard by disconnecting the power for 5 minutes

The motherboard or internal computer may have had a glitch that doesn’t send the right messages to the drain pump. It’s very easy to reset your dishwasher. Simply disconnect the power for 5 minutes, then connect the power again. Most dishwashers are wired directly into the mains, you need to turn it off at the fuse box. But, if you do have easy access to the wall outlet that it’s plugged in then simply unplug it there rather than turning it off at the fuse box.

4. Drain hose at the base of the dishwasher can be clogged

There is a panel at the base of dishwashers that can be removed by unscrewing two screws that are located on the sides of this panel. It’s important that you turn off the electricity to your dishwasher before working underneath your dishwasher as there are wires which you can accidentally touch.

This can be done by unplugging it at the wall outlet. But, chances are it’s hardwired and you need to turn it off at the fusebox. Once that’s done remove the panel at the base of the dishwasher. You will see a host that is about 1 inch (2.5 cm) in diameter that connects to what looks like a small engine. This small engine is the drainage pump.

This hose goes from your dishwasher to your garbage disposal unit. Or is connected to your plumbing. Inspect both ends to see if there’s anything blocking it. You can also squeeze this hose along the length of it to feel if there are any blockages. Refer to this video to see a general overview of how to do this. The specific part about the drainage hose starts at 2 minutes in.

It’s generally attached with a metal clip that you squeeze together to release it. But, you want to have some old towels, and a wide tray, like an oven tray to catch any water. Or, soak it up as it will pour out as you remove the hose. Inspect the end of the hose to see if there’s anything stuck in it.

For new dishwasher installs

When a dishwasher is first installed, there is a special plug called a ‘knockout plug’ that is installed in the garbage disposal unit. It’s located where the drain hose plugs into the garbage disposal unit. It needs to be knocked out using a hammer and a screwdriver as it blocks the opening that the drain hose plugs into.

5. Open and shut valve, or drainage ball is stuck

On some dishwashers there is a rubber flap that stops water from going back up into the drainage tray. This is known as a ‘check flap’. When the drainage pump pumps water into the hose the pressure causes the flap to open. But, it can get stuck in the closed position.

Certain dishwasher models also use what’s called a check ball, to control the flow of water, and it can also get stuck. When it happens often it needs to be replaced.

However, exactly where it’s located, and if your dishwasher uses one can best be found out by referring to your owner’s manual. Then in my opinion it’s best to search Youtube.com for a video about how to replace it. For example, search for ‘how to replace the check ball on a Maytag dishwasher’.

But, replace Maytag with your brand of dishwasher. The same is true inspecting the check flap.

5. Drain pump broken is clogged, or has failed and needs to be replaced

The drain pump can fail both mechanically, and electrically. Or, a piece of debris can have lodged in the drain pump stopping it from spinning. It’s quite an undertaking to remove the drain pump to inspect it. So, you may choose to have a technician diagnose it, and repair it.

However, if you’re fairly good with tools, and reasonably strong or have help from a friend you need to pull the entire dishwasher out from where it is. And then lay it on its back. Then you remove the panel on the bottom of the dishwasher. There you should see a large cylindrical component with a few hoses attached.

It’s held in place by a few screws which you need to remove, and then you can twist and pull the drain pump out. If the drain pump doesn’t have anything blocking the impeller as shown in the video, then you should get a resistance reading on the pump using a voltmeter.

You should also do this if something was blocking the impeller because it’s a major task to take it out again, once you’ve reinstalled it. It should also have a resistance reading of about 200 if the electrical components in the drain pump are all working fine. That covers everything to do with

Copyright protected content owner: ReadyToDIY.com and was initially posted on October 8, 2021.

Dishwasher Not Draining Completely

After a wash cycle a dishwasher can have a puddle of water at the bottom. This indicates there can be a few issues causing it. Here’s what they are and how to identify and fix what’s causing it.

Overall, the filters at the bottom of the dishwasher being clogged is the most common cause. They can be inspected and cleaned fairly easily. If you’ve cleaned them and the problem persists, the drainage hose can be clogged and needs to be cleared.

This is a bit more difficult to do, however, I’ve provided step by step instructions for how to clean the filters with a helpful video to show exactly how to do it. As well as, explained a bunch of different steps ordered from easiest to hardest to fix a dishwasher that isn’t draining completely. Scroll to the top and work through each of the steps starting with step ‘1. Inspect and clean the screens and filter at the base of the dishwasher’.

Dishwasher Not Draining at the End of Cycle

Man happy while looking at the diswasher

I’ve noticed a dishwasher can still function even when it doesn’t drain properly. So, I thought I’d explain what causes a dishwasher to not drain at the end of the cycle. Here’s what I found.

This is caused by the hose that goes from the base of the dishwasher to the garbage disposer being blocked. The 2 filters at the base of the dishwasher can also be clogged with food remnants, and cleaning them can solve this issue. Finally, the drain pump can be defective or clogged.

Full step by step instructions for how to fix this issue have been provided at the top of this article. It’s difficult to know exactly what the issue is ahead of time, so it’s a matter of trying each of the troubleshooting steps until your dishwasher begins working again. Go to the top of this article and start with the first step that explains how to inspect and clean the filters.

Dishwasher Not Draining into Garbage Disposal/Sink

Some dishwashers are connected to the pipes for the sink, whereas others connect to the garbage disposal unit. If you notice that your dishwasher is not draining and it’s connected to the garbage disposer or the sink, here’s what causes it, and how to get it working again.

Generally, the pipe from the drainage pump to the garbage disposal is clogged, and needs to be cleared. If the pipe isn’t blocked a component known as a ‘checking ball’ or a ‘checking flap’ can be stuck, not allowing water to get through.

Also, it can be caused by the drainage pump being blocked, or broken, and the filters that stop food debris from draining into the drainage pump can be full of debris and need to be cleaned under the tap. The most common is the filters at the base of the dishwasher.

To fix this issue follow the step by step instructions at the top of this article. And work your way through each of them until your dishwasher begins draining properly again.

Dishwasher Drain Pump Not Working

Confused man while looking at the dishwasher

The drain pump on a dishwasher sucks water from the base of the dishwasher to the garbage disposer or to the pipes at the bottom of the sink. When the drain pump isn’t working water won’t be removed after a dishwasher cycle and pools at the bottom of the dishwasher. To fix a drain pump that isn’t working here’s what to do.

Remove the drain pump and inspect the impeller for any blockages. Remove any blockages, and ensure the impeller now spins. Test the drain pump for resistance using a voltmeter, it should give a reading of about 200. It’s it has failed mechanically or electrically it should be replaced.

I’ve explained how to do that. Look for step ‘5. Drain pump is clogged or has failed and needs to be replaced’. And follow the instructions in that step.

Most often it’s caused by the two filters at the base of the dishwasher being clogged with food debris, and cleaning them will solve this issue. If it’s not this, then the hose that goes from the drain pump to the garbage disposer or sink can have a blockage.