The Sneaky Reason Why Your Dishwasher Isn't Draining

open dishwasher with clean utensils in it
6 Fixes for a Dishwasher That's Not DrainingKseniya Ovchinnikova - Getty Images

Like all the best kitchen appliances, your dishwasher is there to make your life easier. Whether you're cleaning up after Thanksgiving dinner or sanitizing baby bottles, a dishwasher is the best way to ensure your dishes are clean, safe to use, and spotless even after the messiest of meals. But when it starts to malfunction, the appliance can quickly become more trouble than it's worth. When the dishwasher is not draining, you're left with sopping wet dishes and a puddle of water to mop up.

If you have standing water in your dishwasher, there are a number of potential causes, starting with a block in the drainage hose, and an equal number of DIY solutions. Read on to learn how to fix a dishwasher that's not draining and when to throw in the (literal) towel and call a plumber.

Determine the Type of Draining System You Have

  • High loop to disposal: The drain hose is looped up to the top of the cabinet and connects to the garbage disposal. This high loop is typically held in place with tape, string, or a chain, ensuring that water doesn't flow back into the dishwasher.

  • High loop to drain: The drain hose loops up to the top of the cabinet and connects to the drain line. The connection should be placed above the P-trap on the drain line to prevent sewer gases from entering the dishwasher.

  • Air gap to disposal: The drain hose runs to the top of the cabinet and connects to an air-gap knob at the back of the sink before running to the disposal. The purpose of this air gap is to prevent dirty sink water from draining back into the dishwasher.

  • Air gap to drain: The drain hose runs to an air gap knob at the back of the sink before running to the drain. The connection on the drain lines should be positioned above the P-trap to prevent sewer gases from exiting into the dishwasher. The air gap prevents dirty sink water from flowing back into the dishwasher.

Common Draining Fixes for Dishwashers

Try these easy solutions in order to get your dishwasher back up and running.

Start a Second Cycle

If this is the first time you've noticed leftover water in the bottom of the dishwasher, there's a chance that the previous cycle was interrupted or didn't finish. Start a new wash cycle and see if that solves the problem. If it doesn't, continue below.

Run the Garbage Disposal

Make sure the drainage system linked to your garbage disposal is clean and clear. It's helpful to run your disposal until you hear a soft hum, which indicates there's nothing remaining or stuck in the system.

Remove Any Standing Water

If there's water, even a puddle, remaining in your dishwasher after the cycle finishes, you need to remove it to check the drain. Use a cup, measuring cup, ladle, or small bowl to scoop it out, then dry the bottom of the dishwasher with a towel. Once you get the water out of the way, you'll be better able to see what's going on down there.

Clean the Air Gap

Occasionally, the air gap (that knob at the back of the sink) can become clogged with debris, preventing the dishwasher from draining correctly and leaving standing water in the tub. To see if that's what's going on, twist the air gap counterclockwise to remove it and check inside for gunk. Clean the air gap with water and a stiff brush, put it back, and run the dishwasher cycle again.

Clear the Filter

If your dishwasher's filter is full of food debris or other blockages, the water can't pass through in order to drain fully. Be sure this part of your appliance is clean and clear. Remove it and wash it in the sink, then put it back in place. Want more details? Our dishwasher cleaning guide explains how to do it step by step.

Check the Drain Hose for Kinks

A bent, blocked, or kinked drain hose could prevent the water in your dishwasher from draining fully. Examine the entire hose to be sure it's straight and not being blocked by something under your sink.

Replace the Drain Hose

If your dishwasher is still not draining after checking the drain hose for kinks, you have a bigger problem on your hands. You may need to replace the drain hose. This is more likely if you have an older dishwasher.

Dishwasher Still Not Draining? Call a Plumber

There are only so many DIY fixes, and there are professionals for a reason. Use them! If you've tried any or all of the above draining solutions and they didn't work or worked only temporarily, that may be a sign of a bigger plumbing issue. We recommend calling in a pro to really get to the bottom of why your dishwasher isn't draining.

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