A symptom tells you how the dishwasher is misbehaving, not which part failed. These are the usual causes behind each one; the diagnosis at your home confirms which applies.
Water Left in the Bottom
Standing water in the tub after the cycle ends, sometimes with a drain error.
Likely causes
- Filter clogged with food and grease
- Drain pump jammed by glass, a seed or a bone, or its motor failed
- Drain hose kinked, or its high loop missing
- Air gap or garbage disposal blocked
- New disposal installed without its knockout plug removed
How we narrow it down: The filter is cleaned first, then the drain path is checked: air gap, disposal inlet, hose and loop. The pump is inspected for obstructions and tested. A jammed or failed pump is cleared or replaced.
Dishes Not Coming Out Clean
Food left on dishes, gritty residue, or one rack cleaner than the other.
Likely causes
- Filter clogged, so water recirculates dirty
- Spray-arm jets blocked by debris or scale
- Spray arm cracked or not turning freely
- Water not hot enough: the kitchen tap runs cold first
- Wash pump or diverter weak or failed
How we narrow it down: The filter and spray arms are cleaned and the arms checked for free rotation. The water temperature entering the dishwasher is measured. The wash pump and diverter are tested if cleaning is still poor.
Cloudy Glasses or White Film
A white haze or spots on glasses and dishes. On San Antonio's hard water this is usually mineral film, which rinse aid and the right detergent can prevent. Etching that won't wipe off is permanent damage to the glass surface.
Likely causes
- Hard water minerals left behind as the water dries
- Rinse aid empty or not dispensing
- Hardness setting too low for the local water
- Detergent not suited to hard water
- Water not hot enough to dissolve detergent
How we narrow it down: The film is tested with vinegar: if it dissolves, it's minerals. The rinse-aid dispenser and the hardness or rinse-aid setting are checked where the model has one. Detergent choice is reviewed, and scale is cleared from the tub and spray arms.
Dishes Still Wet at the End
Dishes, especially plastics and cup bottoms, stay wet after the cycle. Many dishwashers dry by condensation and have no drying element, so some wetness on plastics is normal.
Likely causes
- Rinse aid empty
- Heated-dry or extra-dry option off
- Heating element or its thermostat failed on models with one
- Drying vent or fan failed on models with one
- Door opened right after the cycle, before condensation dries
How we narrow it down: The rinse-aid dispenser and dry settings are checked. On models with a heating element, the element and its sensor are tested; on models with a vent or fan, those are checked. The failed part is replaced.
Not Filling, or Humming Without Water
The dishwasher hums or runs but little or no water enters.
Likely causes
- Water supply valve under the sink closed
- Inlet valve coil failed, or its screen blocked by scale
- Float stuck in the up position
- Door switch not confirming the door is closed
- Control not signaling the fill
How we narrow it down: The supply valve is checked and the float confirmed to move freely. The inlet valve is tested for power and flow, and its screen inspected for scale. The failed part is replaced.
Leaking at the Door
Water runs out at the bottom of the door during a cycle.
Likely causes
- Door gasket worn or damaged
- Dishwasher not level, so water reaches the door
- Too much or wrong detergent causing suds
- Spray arm hitting a tall item and spraying at the door
- Door hinge or spring worn, so the door doesn't close tightly
How we narrow it down: The gasket and door alignment are checked and the dishwasher leveled. Detergent type is confirmed, and the spray arms checked for blockage. The gasket or hinge parts are replaced as needed.
Water Under the Dishwasher
Water on the floor under the dishwasher, or water appearing from under the kick panel. Shut off the supply valve under the sink if the leak is steady; water under a dishwasher can damage flooring and cabinets.
Likely causes
- Inlet valve or supply connection leaking
- Drain hose loose or cracked
- Pump seal leaking
- Leak in the tub or a sump gasket
- Leak-detection float tripped because water is already in the base
How we narrow it down: The kick panel comes off and the dishwasher is run to see where water starts. The supply connection, valve, hoses, pump and sump are checked. On models with a leak-detection float in the base, the base is dried after the leak is repaired so the float resets.
Won't Start
The dishwasher lights up but won't run, or does nothing at all.
Likely causes
- Door latch or door switch not engaging
- Control lock or delay start set
- Power off at the switch, breaker or plug
- Thermal fuse on the control failed
- Control board fault
How we narrow it down: The control lock and delay settings are checked, then the door latch and switch are tested. Power to the control is confirmed, and the control's thermal fuse or board is tested if needed.
Door Won't Latch or Close
The door won't stay closed, or it closes but the dishwasher won't start.
Likely causes
- Latch assembly worn or broken
- Door strike bent or out of line
- Dishwasher not fitted squarely in the cabinet
- Rack not seated, hitting the door
How we narrow it down: The latch and strike are checked for alignment and the racks for fit. The latch assembly is tested and replaced if it doesn't hold or signal closed.
Door Drops Open or Slams
The door falls open under its own weight, or snaps shut.
Likely causes
- Door spring broken or stretched
- Door cable frayed or snapped
- Hinge worn
How we narrow it down: The springs and cables are inspected on both sides. They're replaced in pairs so the door balances evenly.
Detergent Not Dissolving or Dispenser Not Opening
Detergent tablets or powder are left in the cup at the end of the cycle.
Likely causes
- Dispenser door blocked by a tall item
- Dispenser latch or actuator failed
- Detergent caked in the cup from humidity
- Water not reaching the dispenser because the spray arm is blocked
- Water too cool to dissolve the detergent
How we narrow it down: The dispenser is checked for obstruction and the latch tested. The spray arms and water temperature are checked. A failed dispenser assembly is replaced.
Grinding, Humming or Loud Noise
A grinding sound, a loud hum without water movement, or knocking during a cycle. Some sloshing and pump noise is normal.
Likely causes
- Glass or debris in the drain or wash pump
- Wash motor bearings worn
- Spray arm hitting a dish or rack
- Drain pump humming because it's jammed
How we narrow it down: The pumps are checked for debris and the spray arms for clearance. The wash motor is tested. The damaged pump or motor is replaced.
Bad Smell
A sour or rotten smell when the door opens.
Likely causes
- Food trapped in the filter
- Standing water from a slow drain
- Drain hose without a high loop, letting sink water back in
- Grease buildup in the tub
How we narrow it down: The filter and tub are cleaned and the drain tested for speed. The drain hose is checked for a proper loop or air gap. The part causing the backflow or standing water is repaired.
Stops Mid-Cycle or Cycle Runs Very Long
The dishwasher stops partway, or a normal cycle takes far longer than usual.
Likely causes
- Water not heating, so the control waits for temperature
- Slow fill from a scaled inlet valve
- Door switch losing contact
- Leak-detection float triggered
- Control or sensor fault
How we narrow it down: Fill time and water temperature are measured, and the door switch checked. Any stored error codes are read. The part that holds up the cycle is repaired.
Error Code or Flashing Lights
A code appears or lights flash in a pattern. Codes are brand-specific and usually describe a condition, such as a leak in the base, a slow drain or no heat.
Likely causes
- Water in the base pan triggering the leak sensor
- Drain or fill problem
- Heating fault
- Sensor or control fault
How we narrow it down: The code is read against the model's service data, then the condition it reports is tested directly. For a leak code, the source of the water in the base is found before the float is reset.
Rust Spots on Racks or in the Tub
Rust spots on dishes, racks or inside the tub.
Likely causes
- Rack coating chipped, letting the tines rust
- Rust from cheap cutlery or pans
- Iron in the water supply
- Tub damage on older units
How we narrow it down: The source is traced: racks, cutlery or water. Rack tine caps or racks are replaced as needed. Tub damage is assessed separately.
Burning Smell or SmokeSafety
A burning or hot-plastic smell, or smoke from the vent or kick panel. Stop the cycle, switch the dishwasher off at its switch or breaker, and leave it off until it's inspected.
Likely causes
- Plastic item dropped onto the heating element
- Wash or drain motor overheating
- Wiring or terminal at the junction box burned
- Control board component failing
How we narrow it down: The heating element area is checked for melted plastic, the motors tested, and the wiring and junction box inspected. Damaged parts are replaced before the dishwasher is used again.
