XT Appliances · Warren
Dishwasher leaves dishes dirty or gritty
Usually a clogged filter or blocked spray arms, and less often a detergent cup that never opened or a weak wash pump.
During the wash, the dishwasher keeps a small pool of water in the sump at the bottom of the tub. The wash pump pressurizes that water and sends it up to the spray arms, which spin and throw it across the racks. Partway through, the detergent cup pops open. A diverter switches the flow between the upper and lower arms so each rack gets its turn, and the filter holds back food so it doesn't land on the dishes again.
Dirty dishes mean one of those steps fell short, and where the dirt shows up usually tells you which one.
Reading the load
Grit or a sandy film, especially on glasses, usually comes from a packed filter. Food it should have held back is getting sprayed onto the load again. If the filter is clean and you hear a loud grinding during the wash, with bits of food left all over the dishes, the chopper blade under the filter may be jammed.
Patches that stay dirty in the same spots, next to dishes that came out clean, point at the spray arms. A jet blocked with food or hard-water scale leaves a stripe unwashed, and an arm that can't spin only washes what sits right above it.
Detergent still sitting in the cup after the cycle is the clearest sign of all. The dispenser door never opened, so the dishes were washed in plain water, and the pump and arms are probably fine.
When one rack comes out clean and the other doesn't, and both arms turn freely with clear jets, the diverter is likely stuck feeding one level. A weak wash pump would leave both racks dirty.
When it's the wash pump
If the dishwasher fills and drains normally but you never hear the spray against the door, or you hear the pump hum with no spray, the wash pump motor or its impeller is the suspect. Weak spray from a pump that runs well usually goes back to clogged arms.
Our technician confirms the tub fills to the right level, then checks that the wash motor runs and drives full pressure to the arms. We watch the dispenser and the diverter through a cycle before replacing anything.
What it usually turns out to be
- Cleaning or upkeepClogged filterA packed filter can't hold food back, so it gets sprayed onto the dishes again. Grit or a sandy film on glasses, with scraps sitting on the filter, points here.
- Cleaning or upkeepClogged or stuck spray armsJets blocked with food or hard-water scale leave stripes unwashed, and an arm that can't spin only washes what sits right above it. Dirty patches in the same spots every time point here.
- PartDetergent dispenser not openingIf detergent is still sitting in the cup when the cycle ends, the dispenser door never opened and the load washed in plain water. The pump and arms are probably fine.
- PartDiverterThe diverter sends water to the upper and lower arms in turns. When one rack comes out clean and the other doesn't, and both arms are clear, it's likely stuck on one level.
- PartWash pumpThe wash pump pressurizes the water that feeds the arms. If the dishwasher fills and drains but never sprays, or the pump hums with no wash action, both racks stay dirty.
Try this first
- Remove the filter under the bottom rack and rinse it until the mesh is clear.
- With the racks loaded, turn each spray arm by hand to make sure no tall item or pan handle stops it.
- Look for food or white scale in the spray arm jets and clear them with a toothpick.
- After a cycle, check the detergent cup: soap still sitting there means the dispenser door never opened.
Stop using it and call now if
- A loud grinding during the wash that doesn't go away after you clean the filter
- A burning smell
Other dishwasher problems
- Dishwasher won't drain
- Dishwasher leaking on the floor
- Dishwasher won't start or stops mid-cycle
- Dishwasher not drying the dishes
Or go back to dishwasher repair in Warren.