Quick Answer
If your dishwasher won't drain, check the filter, drain basket, garbage disposal knockout plug, sink drain, air gap, and visible hose kinks. Standing water can also come from a clogged hose, failed drain pump, stuck check valve, bad control, or installation issue. Stop if water is near electrical parts, the dishwasher smells hot, or the pump hums without draining.
Symptoms at a Glance
Standing water
Likely cause: Clogged filter, blocked drain hose, failed drain pump, or sink drain issue.
Homeowner action: Clean the filter and check the sink/disposal drain.
Humming with water inside
Likely cause: Jammed drain pump, glass debris, motor issue, or control problem.
Homeowner action: Stop the cycle and avoid forcing repeated drain attempts.
Water backs into the sink
Likely cause: Clogged sink drain, garbage disposal blockage, or air gap problem.
Homeowner action: Clear the sink/disposal side before blaming the dishwasher.
Bad odor with standing water
Likely cause: Food debris in the filter, sump, hose, or drain path.
Homeowner action: Clean accessible parts and run a rinse cycle if draining returns.
Leak during drain cycle
Likely cause: Loose hose, cracked hose, clogged drain, or pump seal issue.
Homeowner action: Stop the dishwasher and schedule service.
Repair Difficulty Meter
DIY difficulty: Low for cleaning the filter, checking the air gap, and inspecting visible hose kinks.
Estimated time: 15-40 minutes for safe external checks.
Tools needed: Towels, cup or small container, flashlight, soft brush, owner's manual, and gloves.
Safety risk: Moderate because dishwashers combine water, electricity, sharp debris, and hot surfaces.
When to call a professional: Call when the pump hums, leaks appear, water reaches wiring, the drain hose must be removed, or the dishwasher needs internal access.