My Dishwasher Won’t Drain: 10 Reasons & 8 Fixes

It’s time to get the dishes from the dishwasher machine, but yuck! A pool of stagnant water. That’s when you realize your dishwasher won’t drain. So, what should you do?

Unplug the dishwasher from the power source, remove the dishes, and drain the stagnant water with a towel. Check the filter, drain hose, and other parts for clogging and thoroughly clean them. If the dishwasher is malfunctioning, talk to a qualified plumbing professional for help.

10 Reasons Your Dishwasher Isn’t Draining

Like other dishwasher problems such as a faulty start button, it can be hard to tell why your dishwasher is not draining immediately. You need to check it thoroughly to identify the problem. That way, you can minimize the chances of bacteria accumulating and the stagnant water becoming smelly.

Here are ten reasons that can cause your dishwasher machine not to drain:

1. Dirty Filter

Filters are vital in any dishwasher machine. They prevent food particles, grease, and other debris from depositing into the dishwasher. Therefore, you need to maintain them properly to enable the appliance to run efficiently.

If you fail to clean the filters regularly, they can block. This will affect your dishwasher’s drainage system. Luckily, it’s easy to clean them. All you need to do is to remove the filters from the dishwasher and wash. You will find them at the dishwasher bottom side near the spray arm.

When cleaning, place the filters under running tap water to remove all the debris. However, if the grime is tough, clean with hot soapy water and a cloth. Return the filter in the dishwasher once clean.

2. Blocked/ Faulty Drain Hose

If the filters are okay, but still your dishwasher won’t drain, thoroughly examine the drain hose. The drain hose enables dirty water to flow from the machine. First, check the stability of the hose and its connection points. Also, confirm if it is clogged.

Luckily, you can get rid of the clogs and kinks without necessarily buying a new hose. But if there is a need for a replacement, the parts aren’t expensive either.

3. Use of Liquid Detergent

The type of cleaning agent you use can also cause your dishwasher not to drain. Most appliances require powdered detergents. So, if you decide to use a liquid detergent in such a machine, it can form a lot of suds. Thus, lowering the speed at which the water drains.

Nonetheless, if you prefer using a liquid detergent, decrease the amount per cycle to minimize creating a lot of foam.

4. Damaged Drain Pump

Foreign objects like broken glass can get to the drain pump and inhibit its functioning. At a point, you may hear some weird noises coming from the pump. That’s a clear indication that it’s struggling to perform its function. Therefore, it may fail to drain water after every wash cycle.

To check the drain pump, you have to open the bottom of your dishwasher, take out the base plate, and disconnect the water inlet hose. If you can’t handle that by yourself, call a professional plumber to do the job.

5. Clogged Air Gap

Does nothing seem to work? Don’t panic yet. Try to check the air gap. Perhaps it can be clogged with debris and grease. If you are wondering where to find the air gap, check your sink for the cylindrical covering. Use a small brush to get rid of grime and other obstructions.

6. Old Plumbing

As years go by, your plumbing system gets to wear out. You may start to experience problems like poor drainage, especially during colder months. With that, you might have to replace the older plumbing with a new one.

7. Intact Knockout Plug

If your dishwasher is not draining yet still new, probably the culprit is the knockout plug. Many manufacturers fail to tell customers to remove it when installing the dishwasher. But if you are already a victim, you can still get rid of it.

Just pull out the drain hose connecting the disposal garbage and the dishwasher. Pass a blunt object through the hole and smack the knockout plug to fall inside the disposal garbage. Afterward, pick it by hand.

8. Frozen/Faulty Valves

The water inlet valve can become defective or frozen. As a result, it may fail to shut off the water flowing to the dishwasher or fail to provide water at all. If the former happens, it could be the reason for the standing water in your dishwasher.

9. Power Source Failure

The power source breakers and outlets may fail to work efficiently, thus causing the drainage problem. You might check them to ensure they are okay.

10. Dishwasher Malfunction

If this is the case, contact a qualified plumbing technician to come and examine your dishwasher. If the dishwasher is still new, you can talk to the warranty office.

Step By Step Guide To Drain Your Dishwasher

You don’t have to call a professional every time your dishwasher won’t drain. Be in control of your appliance by following the steps below to unclog it yourself;

Step 1: Turn Off The Appliance

First, switch off the power supply to the dishwasher machine and garbage disposal. As you know, electricity and water don’t sail the same boat.

Step 2: Prepare The Dishwasher

Remove all the dishes from the appliance. You may clean them later after fixing the dishwasher. Also, take out the dishwasher’s bottom rack. That way, you can get to the inner parts of the machine with ease.

Step 3: Get Rid of The Stagnant Water Using a Towel

Wipe the standing water slowly with a towel. That way, it will be easier for you to clean the dishwasher. Again, you will minimize the chances of sliding and falling while handling the machine.

Step 4: Clean Or Change The Filter

Check your manual to locate the filter in the dishwasher. In most cases, you will find it at the inside bottom of your machine. Pull it out and thoroughly clean it.

Step 5: Remove The Drain Hose And Clean

The drain hose is often behind the dishwasher connecting the appliance with the garbage disposal. To disconnect the drain hose from your dishwasher, you may need pliers to loosen the clamp. Also, put a small bowl beneath the hose to hold any water spills. Unclog and clean the drain hose.

Step 6: Check The Other Dishwasher Parts For Blockages And Clean

The other dishwasher parts you need to check, include the garbage disposal drain pump, valves, and air gap. Eliminate all the debris that might clog them.

Step 7: Reassemble Your Dishwasher

After cleaning and drying the parts, reassemble your dishwasher, ready for a wash circle.

Step 8: Run a Wash Circle to Check If The Dishwasher Is Draining Water Well

Plug the machine into a power source and run a wash cycle to check the drainage. Also, listen for any weird sound. If nothing is alarming, you are good to go.

Parting Shot

Don’t panic if your dishwasher won’t drain. Probably it’s due to clogging, which can be resolved through proper cleaning and following the steps mentioned herein. However, if it is due to malfunctioning or breakages, I recommend you seek help from a qualified plumbing professional.