The short answer
A Home dishwasher left with water in the bottom is usually blocked at the filter or downstream at the sink waste rather than suffering a dead pump. The first thing to check: filter and sump blocked with debris. A small amount of water in the sump is normal; a full tub is not.
What you observe
- A tub with standing water at the end of the cycle — The classic presentation, and it says nothing yet about which part.
- Water rises in the sink when the machine drains — That is a downstream plumbing blockage.
- NEAR MISS — water is on the kitchen floor rather than in the tub — That is a leak, not a drainage fault. Read the leak page for this brand instead.
Causes, most likely first on a Home dishwasher
- Filter and sump blocked with debris — The filter catches everything the racks let through. Once it is loaded the machine cannot move water through it fast enough, and what should have been pumped away simply stays in the tub. A badge-engineered machine uses standard consumables, and standard consumables are what fail first. This is the cheapest cause on the list and the most common one.
- Waste disposer knockout plug never removed — When a dishwasher is connected to a new disposer, a plug inside the disposer inlet must be knocked out. If it was missed at installation the machine can never drain, and it has never drained properly since. These machines are self-installed more often than not, so the hose run, the levelling and the standpipe are live suspects rather than givens.
- Drain hose kinked, or the high loop missing — The hose has to rise before it falls, so that waste cannot run back into the machine. Crushed behind the cabinet, or lying flat under the sink, it either blocks or siphons, and both leave water in the tub. The drain path is ordinary hose and an ordinary trap, so it blocks the ordinary way, and that is why it is checked before any part is suspected.
Check in this order, and why
- Lift the filter out and look at it and the sump beneath — First, because it is free, quick and the most common cause of all. It is first because it is the highest-ranked cause here.
- Ask whether the machine has ever drained properly since installation — Second on any recent installation: a machine that never worked is a different story from one that stopped. Second: the next most likely, and free to rule out.
- Look under the sink at how the drain hose is routed — Third: free to inspect, and the usual finding after any work under the sink. Third, and only once the two above are clean.
What an owner can safely check
- Remove the filter, rinse it under a hot tap and clear the sump — Wear gloves and expect broken glass. Scoop the standing water out with a cup and a sponge first.
Tools: gloves, cup, spongeAbout 30 min
- Scoop the standing water out with a cup and a sponge before anything else — You cannot inspect a filter under water, and it makes everything afterwards easier.
Tools: cup, sponge, towelsAbout 20 min
- STOP HERE if the next step means removing the pump or metering it — That is where the owner checks end and a service call begins.
Before you open anything
Safety
Switch the machine off at the breaker before removing any panel or reaching behind it. A capacitor can hold a charge after the power is off. Wear gloves when clearing a filter or a sump: broken glass collects there and is not always visible. Water standing under a kitchen cabinet with live wiring behind it is a real hazard, so dry the area before working in it.
When to call a technician
Call when the filter is clean, the hose is correctly routed and the sink waste is clear, and the machine still will not empty, or when the pump is silent at the drain step. Call a plumber rather than an appliance technician if the sink backs up as the machine pumps: the machine is working and the house drain is not. Call immediately if water has reached wiring or a neighbouring appliance.
Nearest pages of this class
What this page does not cover
This page covers Home dishwashers as a class, not one family or model line. Where a family- or model-specific page exists for your unit, that page is the more specific answer and the one to read first. Deliberately not here: wiring colours, torque figures, part numbers and service-manual sequences, which differ by family.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
