Dishwasher Not Draining? Causes & What to Check

1. Confirm when the water is left behind

Note whether the cycle finished, was cancelled or stopped with an error. A small amount of water below the filter in the sump can be normal on some models; a pool covering the tub floor is different. Record whether the dishwasher drains at first and water later returns. That distinction helps separate a drain fault from water backing up through a connection.

2. Clean the removable filter

Remove the lower rack and follow the owner's manual to unlock the filter, if your model has an owner-removable one. Rinse it and clear food residue with a soft brush. Avoid abrasive tools, and reinstall it in the correct locked position. Sharp fragments can be hidden in the sump; do not probe blindly or dismantle a pump. Only access an owner-serviceable pump cover when the model's manual permits it.

3. Look at the accessible drain route

With power isolated, look under the sink for a visibly crushed or kinked drain hose. Do not disconnect hoses or move the built-in unit for this check. If the sink also drains slowly, the shared waste connection or household plumbing may need attention. An air gap, where fitted, can become obstructed; use its manufacturer's cleaning instructions. Keep the hose routing specified by the dishwasher installation manual.

4. Consider recent installation or plumbing work

If the problem started after a dishwasher or garbage disposer was installed, tell the installer. Where the dishwasher connects to a disposer, its inlet knockout plug must have been removed during installation. A missed plug, disturbed hose or obstructed sink connection can prevent drainage even with a working pump. This is a connection check for the installer, not a reason to replace the pump without diagnosis.

5. Record sounds and the exact error code

Humming, grinding, silence during draining and a displayed code are useful observations, but none proves that the pump has failed. A technician can check for an obstruction, pump operation and the relevant wiring or controls. Follow the model-specific cancel/drain procedure only if there is no leak or electrical warning. Repeated resets do not remove a blockage or repair a failed component.

When professional diagnosis is appropriate

Arrange diagnosis when standing water returns after the accessible filter check, the drain pump makes abnormal sounds, the cycle repeatedly stops or a code returns. Stop using the appliance if it leaks or trips a breaker. Work requiring removal from cabinetry, pump testing or hose disconnection belongs with a qualified technician; a blocked household drain may need a plumber.

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What to share when requesting service

Share the brand, model, code, whether the cycle finishes and any recent sink or installation work. Mention whether the sink drains normally and whether water returns after the dishwasher empties.

Related guidance

• Dishwasher Leaking? Common Causes & What to Check
• Dishwasher Not Cleaning Properly? Causes & Fixes