Dishwasher Won’t Drain – What To Check – How To Fix

Dishwasher not draining? Did you just open up your dishwasher and found it filled up with water or there is water all over the kitchen floor? If so then it is obvious your dishwasher has a problem draining the water. There are many things that could be the cause of the problem. You do not need to call a repair person as of yet. There are a number of simple things you can check yourself to fix your dishwasher.

Dishwasher parts illustrationSOLUTION 1: Is something at the bottom of the dishwasher blocking the drain? Check the bottom of the dishwasher for a piece of food or a foreign object that could be blocking the drain. Sometimes if a glass cup breaks while in your dishwasher, a piece of glass will fall and cover up the drain. Use caution and stick your hand in the water and feel around for anything that should not be there. Use a flashlight if necessary and remove whatever may be blocking the drain. It may be necessary to completely remove the drain cover. Usually a few screws hold this in place. Remove the cover and see if anything is clogging it up. Remove anything that should not be there and replace the drain cover. If you found anything large that was blocking the drain, then you may have fixed the problem. Run a short dishwasher cycle test and observe. If the dishwasher is draining properly, you fixed it.

dishwasher-drain-basketCheck the drain basket at the bottom of the dishwasher for anything that may be preventing it from draining

SOLUTION 2: Did you recently install a garbage disposal under the sink? If so the knock out plug has probably been left in the disposer. This will prevent the water from draining out of the dishwasher. To fix this, remove the plug on the side of the garbage disposal so your dishwasher can properly drain out the water. Once the plug is removed run the dishwasher through a short test run and make sure it drains the water.

remove-disposal-plug

New disposals have a knock out plug in the connection for the dishwasher drain hose
This plug needs to be removed or the dishwasher will not be able to drain

SOLUTION 3: Is the water drain line from the dishwasher to the bottom of sink crimped or clogged? Usually your dishwasher will be located right next to your kitchen sink. There is a water drain line that goes from your dishwasher to the garbage disposal or the bottom of your kitchen sink. Look under the kitchen sink and make sure that a box of detergent or similar is not pushing against and crimping the drain hose. If it is not crimped, it is possible the drain hose may be clogged with a chunk of food or from long term build up of food particles. Get a screwdriver and remove the drain line from the side of the garbage disposal. Blow air through the line to make sure there is nothing clogging it. It this line is not clogged then go to next step.

dishwasher_drain_hoseMake sure your dishwasher drain hose is not crimped or clogged

SOLUTION 4: Is the drain pump beneath the dishwasher faulty? The only way to actually fix this (if you have zero mechanical and electrical knowledge) is to call a repair company or use an appliance forum online to ask in depth questions. If you can remove and replace the dishwasher drain pump yourself, check online for the best dishwasher drain pumps and parts as these parts are usually cheaper online than at most stores.

dishwasher drain pumpA faulty dishwasher drain pump will not let the dishwasher drain out the water

SOLUTION 5: Is the check valve stuck? The check valve could be stuck in the closed position. This valve is what prevents water from returning to the dishwasher after the water drains out. If the valve gets stuck in the closed position it completely prevents the water from draining out of the dishwasher. The check valve is usually located in the outlet of the pump attached to the drain hose. Check this valve to be sure it is in proper working order and not stuck closed.

dishwasher check valve located on pumpA stuck dishwasher check valve (usually located on pump) will cause NO DRAIN

Do you have any other reasons a dishwasher will not drain? Please leave a comment below.

8 thoughts on “Dishwasher Won’t Drain – What To Check – How To Fix”

  1. My Thermador Dishwasher DWHD64EP won’t drain. It has been working fine for 5 years. Blew out the drain hose with a mini compressor. No blockage. Checked the backflow flap. Works fine. Pulled the drain motor. No debris around the impeller. Checked the OHM and it was reading as almost a short. So I hooked up two wires from a household plug directly to the motor. It spins fine. No noise. Even placed my finger lightly on it to check for a slipping impeller. No issue there. Reinstalled the drain motor and tried again. Still won’t drain. Tried the Cancel Drain, by holding the 2 buttons down for at least 3 seconds. but nothing seems to be happening. The impeller isn’t spinning.

  2. I am writing this 2 hours after purchasing a new in the box whirlpool model WDF110PABW4 dishwasher. I brought it home hooked it up and ran it thru a complete cycle and wouldn’t you know it water does not drain.Before this I had a friend who gave me a new Maytag and it did the exact same thing. The drain hose is free of any blockage, the plug is out of the garbage disposal, and the sink plumbing is free of any blockage.

  3. DIY Project Help Tips

    Vince,
    You may have a bad drain pump or something may be clogging or blocking it. If you have fully cleaned it out, and it still will not drain, then test the pump and motor to be sure it is in working order. Check to be sure the wires are connected and secure. Is the thumping noise coming from the bottom of the dishwasher or is it possibly a spray arm hitting something in the dishwasher?
    -RR

  4. My dishwasher stopped draining. It makes a continuous thumping sound. I manually got the water out and cleaned the filter but that wasn’t the problem. Any thoughts on what it might be?

  5. Richard Hernandez

    I had a problem with my dish washer awhile back that wouldn’t drain and a couple of gentlemen gave me some suggestions. The problem was that I lost this website and couldn’t remember what it was until now. When I Installed a disposal I didn’t remove the knock-out plug when I hooked up the drain hose. Anyway, I just wanted to thank everyone that helped me solve this problem. Now it is working perfectly. I hope this is the correct place to post this so the gentlemen who helped can read it.

  6. DIY Project Help Tips

    Roger Hilyer,
    If you have a bad check valve on your dishwasher you should be able to just replace the valve. But it depends on your dishwasher make and model. Can you provide that to us?
    -RR

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