MAPIWhy Is My Dishwasher Not Draining?
Standing water does not point to one single failure. The useful first checks are the parts of the drain path where debris, routing or connection problems can physically stop water from leaving.
If water remains in the bottom of the dishwasher after a cycle, Whirlpool recommends checking the filter and sump, drain hose, sink or garbage-disposal connection and drain path before assuming a control failure. Pump or electrical issues may require service.
Key takeaways
- A clogged filter or debris in the sump can restrict drainage.
- A kinked or blocked drain hose can stop water from reaching the sink drain.
- A disposal knockout plug, clogged sink connection or air-gap problem can block the drain path.
- A jammed or failed drain pump can cause humming or no water movement.
What it actually means
A dishwasher-not-draining problem means water remains in the tub after the machine should have pumped it into the household drain system.
The main explanation
Whirlpool's current drainage guidance starts with the drain path: filter and sump, hose routing, garbage-disposal or sink connection, air gap and pump. A partial restriction may leave some water near the filter, while more severe blockage or pump problems can leave higher standing water.
Main causes and reasons
1. Filter or sump is clogged
Whirlpool says neglected filters and food debris in the sump can restrict water flow to the drain system.
How to recognize it
- Water remains near the filter
- Food debris is visible
- Drainage improves after cleaning
Why it matters: These are common places for physical blockage to develop.
2. Drain hose is kinked, blocked or routed incorrectly
Whirlpool says the hose must be clear and correctly routed with the required high loop or air gap.
How to recognize it
- Hose is crushed or kinked
- Water backs up
- The problem began after under-sink work
Why it matters: A restricted or misrouted hose can prevent water from leaving or allow it to return.
3. Sink or garbage-disposal connection is blocked
Whirlpool notes that a clogged disposal, sink connection or an unremoved disposal knockout plug can stop dishwasher drainage.
How to recognize it
- A new disposal was installed
- The sink drains slowly
- The dishwasher connects through the disposal
Why it matters: The dishwasher depends on the downstream household drain path.
4. Drain pump is jammed or not operating
Whirlpool says humming with no water movement can point to a jammed impeller or obstruction in the pump area.
How to recognize it
- A steady hum occurs during drain
- No water moves
- Hard debris may be present near the pump
Why it matters: The pump is the component that actually moves water out of the tub.
How to identify your situation
A partial restriction in the filter, sump or hose is possible.
Next: Inspect and clean the filter and sump, then check the hose.
A severe blockage or non-running pump is more plausible.
Next: Stop using the dishwasher and inspect the drain path or schedule service.
The pump impeller may be jammed or obstructed.
Next: Check for accessible debris according to the model instructions or schedule service.
The disposal knockout plug or connection may be blocking drainage.
Next: Verify the installation according to the appliance and disposal instructions.
What you can do
- Turn off power before accessing drain components.
- Clean the dishwasher filter and inspect the sump for debris.
- Check the drain hose for kinks, blockages and correct routing.
- Inspect the sink, air gap or garbage-disposal connection.
- Schedule service if the pump, wiring or control system is suspected.
Common misconceptions
Whirlpool lists several blockage and installation causes that should be checked first.
A hose can be kinked, blocked internally or routed incorrectly.
Whirlpool specifically notes the disposal knockout plug and connection as drainage checks.
When it may be a bigger problem
Schedule service if the dishwasher still will not drain after accessible filter, sump, hose and connection checks, or if electrical, pump or internal component diagnosis is required.
Frequently asked questions
Can a clogged dishwasher filter stop drainage?
Yes. Whirlpool says a clogged filter can restrict drain flow.
Can a garbage disposal cause dishwasher drainage problems?
Yes. Whirlpool lists disposal blockages and an unremoved knockout plug among drain causes.
Can a kinked drain hose stop a dishwasher from draining?
Yes. Whirlpool says the hose must be clear and correctly routed.
What does a humming dishwasher that will not drain suggest?
Whirlpool says a steady hum with no water movement can point to a jammed impeller or obstruction in the pump area.
Sources
- Dishwasher Not Draining — Whirlpool Product HelpOfficial
Written by Mapiance Editorial Team
The Mapiance Editorial Team researches, writes, reviews, and maintains practical guides and explainers for MAPIANCE.
Reviewed by Mapiance Editorial Team
Published Sep 16, 2026 · Updated Sep 27, 2026 · Verified Sep 13, 2026