The short answer first
On a KitchenAid dishwasher, water left in the bottom is usually clogged filter and sump screen rather than a failed pump. The drain path is short and every part of it is reachable: filter, sump, hose, waste connection. Most of these are cleared in under half an hour with a cloth and a bowl.
What you are seeing
- Nothing at all happens during the drain phase — complete silence — Silence where there should be a pump points at the electrical side rather than a blockage.
- A humming sound during the drain phase with nothing leaving — The pump is being asked to run and cannot move water — a jam or a blockage downstream.
- A smell from the tub between cycles — Standing water and trapped food do this within a day or two, and it clears as soon as the blockage does.
- NEAR MISS — the dishes are dirty but the machine drains fine — If the tub empties properly and the dishes are still poor, the cleaning page is the right one: spray arms and water temperature are the suspects there.
What goes wrong here, in order
- Clogged filter and sump screen — A dishwasher recirculates its water many times during a cycle, so the filter is doing its job constantly rather than once. It loads faster than owners expect and it is the first restriction water meets on the way out. It comes first for a practical reason: the check takes minutes and it decides which half of this list you need. This is a brand with a service network behind it, so the ranking assumes parts can be had and focuses on which one is actually at fault.
- A hose with no rise in it, so waste water siphons back — This cause appears at a very specific moment: after the machine has been pulled out for cleaning or refitted after a kitchen job. The hose gets trapped against the wall and the fault starts that day. It ranks below the first only because the first is more common, not because it is harder to find.
- An impeller stopped by something it swallowed — The drain pump sits under the sump and pushes water out through the hose. A small object that gets past the filter — a fragment of glass, a cherry stone, a plastic tag — can stop the impeller dead, and the pump then hums without moving anything. Third, because the evidence for it only means something once the two above are ruled out.
- A slow household drain backing up into the machine — It is on the list because owners rarely connect the two, and because a plumber and a technician are different calls: ruling this in before booking saves an entire wasted visit. Last: it accounts for the smallest share of these calls, and every check above it is quicker to make.
The order to check in
- Twist out the filter in the base of the tub and look at the mesh — A film you can see through is fine; a mat of debris is the fault, and it is visible the moment the filter is out. Start at this check: it is the one most likely to end the job on its own.
- Feel along the hose where it passes behind the machine — A hose flattened between the cabinet and the back of the machine is hard to see and easy to feel. Second, once the first check is clean.
- Listen at the machine during the drain phase with the door open a crack — A hum with no water movement is a jammed impeller; silence is an electrical fault. Third: by now the answer is usually already in hand.
The steps, with tools and times
- Bail the standing water out, then clear the sump by hand — Use a jug and a cloth; wear a glove, because broken glass is common in a sump.
Tools: jug, cloth, gloveAbout 25 min
- Straighten the hose and secure the high loop up under the worktop — Use the clip the machine came with, or a cable tie to the cabinet wall.
Tools: cable tieAbout 20 min
- Note whether the pump hums, and for how long, before calling — That one observation shortens the visit and often decides which part is ordered.
About 10 min
- STOP here and write down what each check showed — A technician arriving with the cheap causes already eliminated spends the visit fixing rather than repeating your work.
The part that is not optional
Safety
Isolate the machine at its socket or switch before working on it, and close the water supply valve under the sink before opening any fitting. Water arriving under pressure into a cupboard does more damage in an hour than the repair costs.
Where the owner fix ends
Stop at the point where the next step means taking the machine out from under the worktop. Before that, everything is reachable from inside the tub and from the cupboard under the sink, and most of these faults are settled there.
Where to go next
Generalized information
What you are reading is written for the class, not for one KitchenAid model. A family- or model-specific page, where one exists, carries what this page cannot: the exact part numbers, the board layout and the disassembly order for that line. Go there first if your model is named.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
