Dishwasher hums but does not wash: a brief hum can be a drain or inlet valve, but continuous humming without water movement can mean a blocked pump, closed supply or seized circulation motor. Check that the supply valve under the sink is open and that the inlet screen is not clogged.
What this covers
- Dishwashers · noise
What it does not cover
Differential
Likely causes of “Dishwasher hums but does not wash”, and how to tell them apart
- 1
The water supply is closed or the inlet is blocked
What separates it A hum at fill with no water arriving and the tub stays dry, sometimes after plumbing work.
How to confirm Check that the supply valve under the sink is open and that the inlet screen is not clogged.
- 2
The drain or circulation pump cannot turn because of a jam
What separates it A steady hum during wash or drain with little water movement, and glass or a small object is in the sump.
How to confirm With power off, check the filter and pump cover for debris, wearing gloves.
- 3
A stuck spray arm or load is loading the motor
What separates it The hum comes with a scraping or rubbing sound and the arm does not turn freely.
How to confirm Spin the arms by hand and clear anything blocking their rotation.
- 4
The circulation motor or its bearings are failing
What separates it A hum persists after the path is clear and the pump does not move water.
How to confirm This is the conclusion once the supply, filter and arms are ruled out and it needs service.
Before you touch a setting
Record this first — changing settings destroys the evidence
- Which stage of the cycle the hum occurs in: fill, wash or drain.
- Whether water fills, circulates and drains properly.
- Whether the hum comes with a hot or burnt smell.
Try in this order
0 of 9 completedObserve before changing anything
ReversibleIdentify whether the hum occurs at initial drain, fill or the main wash stage.
Isolate the failing boundary
ReversibleCheck supply, filter, pump cover and spray-arm freedom with power disconnected.
Apply the narrow correction
ReversibleCorrect the accessible restriction and run one empty short cycle.
Listen to when the hum happens
ReversibleA hum at the start of a cycle, when the machine fills, points to the inlet valve or the pump. A hum with no water moving means the pump is working but cannot move water, usually because of a blocked drain or a stuck impeller. Note when it happens.
Check the filter and the sump
ReversibleRemove the lower rack and the filter and look in the sump for glass, bone or a label. A hard object can jam the pump and cause a hum. Remove it carefully.
Check the drain hose and the disposer
ReversibleA drain hose that is kinked or a disposer knockout plug that was never removed prevents drainage. Clear the sink disposer and check the hose behind the machine.
Run a short cycle with the door shut
ReversibleListen again. A deep hum that stops when the pump finishes is often normal motor noise. A loud or rising hum, or a burning smell, means you should stop and call.
Call a technician for a pump or motor fault
ReversibleIf the hum continues with a clear sump and drain, the pump motor may have failed. Quote the model and serial from the label and describe when the hum occurs.
Verify the result and stop at the boundary
ReversibleStop for a hot motor smell, no water circulation or a hum that persists after the path is clear.
Stop boundary
When this stops being a self-service repair
- !Stop for a hot motor smell, no water circulation, or a hum that persists after the path is clear; disconnect power and request service.
Evidence ledger
Sources behind this answer
Exact questions
Common questions
Is a brief hum at the start normal?+
A short buzz when a valve opens or when the drain pump starts is normal. A hum that lasts through the wash with no water movement is not.
Why does my dishwasher hum but not wash?+
A motor that hums and does not turn is often a jammed pump, with a piece of glass or a seed in the impeller, or a failed motor. Unplug the dishwasher, then check the filter and the sump for debris.
Which humming is normal?+
A short hum while the dishwasher fills or drains is the valve or pump working. A hum that goes on without the water moving is the one to investigate.
Is a hum normal?+
A low hum while the pump runs can be normal.
What causes a loud hum?+
A blocked pump, a stuck impeller or a failing motor.
Can I fix it myself?+
You can clear the filter and the drain; a motor needs a technician.
Should I stop using the dishwasher?+
Yes, if there is a burning smell or no water moves.
Is humming always a problem?+
A brief hum is normal, but continuous humming without water movement can mean a blockage.
When should I call a technician?+
If it hums and does not wash after these checks.