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True Trade Path

Diagnostic guide

Dishwasher Not Draining

Standing water in the bottom of your dishwasher after a cycle — most causes are local and fixable without a service call.

System
Plumbing
Causes covered
7
You can check
5 without a technician

Stop and read this first

  • Disconnect power at the breaker before reaching into the dishwasher.
  • Standing water in the dishwasher can harbor bacteria — run a sanitize cycle after clearing the drain.
  • If the dishwasher shares a drain with a garbage disposal, never run the disposal while the dishwasher is draining.

Work through these in order

Ordered from most to least likely. Working top down means you rule out the cheap, common causes before paying anyone to look at the expensive, rare ones.

  1. Clogged filter or drain basket

    CommonYou can check
    How to check
    Water pools at the bottom after every cycle. Filter at the bottom of the tub is coated with food debris.
    The fix
    Remove and clean the filter assembly. Rinse under running water and reinstall. Clean monthly.

  2. Blocked drain hose

    CommonYou can check
    How to check
    Hose running from the dishwasher to the disposal or drain is kinked, clogged, or installed with a high loop missing.
    The fix
    Disconnect the hose and flush with water. Ensure the hose has a high loop at least 20 inches above the floor.

  3. Garbage disposal knockout plug not removed

    CommonYou can check
    How to check
    New dishwasher or new disposal installation. Dishwasher drains through the disposal.
    The fix
    Knock out the plastic plug inside the disposal inlet where the dishwasher hose connects. This is the most common new-install mistake.

  4. Clogged air gap (if installed)

    CommonYou can check
    How to check
    Water spills from a small cylinder mounted on the sink or countertop during drain cycle.
    The fix
    Remove the air gap cap and clean debris from the inner tube. Flush with water.

  5. Failed drain pump

    PossibleNeeds a pro
    How to check
    Filter and hose are clear but water remains. You hear the pump attempt to run but nothing drains.
    The fix
    A technician replaces the drain pump ($150 to $350). Check for debris jamming the pump impeller first.

  6. Main line or sink drain clog

    PossibleYou can check
    How to check
    Kitchen sink also drains slowly. Multiple fixtures gurgle when the dishwasher runs.
    The fix
    Snake the sink drain ($100 to $250 DIY or professional). If multiple fixtures are affected, the main line may be blocked ($200 to $800).

  7. Check valve stuck closed

    UncommonNeeds a pro
    How to check
    Water drained previously but stopped after a long period of disuse.
    The fix
    A technician replaces the check valve in the drain hose or pump assembly ($100 to $250).

Once you know what it is

Step one

Know what it should cost

Get the range before you call, so the first number you hear is not the only number you have.

Step two

Decide repair or replace

On equipment near end of life, the repair is usually the first of several.

Step three

Check the quote

Compare against the typical range and confirm the terms before you sign.

Sewer Line Repair & Replacement cost guideRepair or replace calculatorEstimate repair costAnalyze a quote

What the fix costs

Tools for this decision

Other symptoms