The short answer
A dishwasher that leaves water in the base usually comes down to one thing: the filter and sump are blocked. Next on the list: something is jammed in the drain pump. The first check needs a sponge and a cup and nothing else, and it resolves most of these.
What you observe
- Water standing in the base at the end of the cycle — The cycle ran; the water never left.
- Water standing in the base at the end of the cycle — The cycle ran; the water never left.
- A buzz or hum from the base and the water stays put — Something is stopping a pump that is being asked to run.
- It has never drained well since it was installed — A fault present from day one is an installation fault.
- NEAR MISS — a little clean water in the sump between cycles — A small amount there is normal and keeps the seals from drying out.
Causes, most likely first on this machine
- The filter and sump are blocked — First on this machine. Everything the dishes carry ends up in the sump, and the filter is what stops it reaching the pump.
- Something is jammed in the drain pump — Ranked here because a jam and a failed pump sound completely different, and a jam is free to fix.
- The air gap or the disposer connection is blocked — Ranked here because the fault is in the plumbing rather than the appliance, which is where people look last.
- The drain pump has failed — Last, and deliberately — it is the only cause here that needs a part, and the causes above account for most calls.
Check in this order, and why
- Lift out the filter stack and clear the sump beneath it — Everything the dishes carry ends up here.
- Listen for a hum at drain time with no water moving — A hum means the pump is trying; silence means it is not.
- Check the air gap and the disposer spigot for a blockage — A knockout plug left in place blocks the drain permanently.
- Listen at the base at the moment it should drain — Silence points at the pump; a hum points at a blockage.
What an owner can safely check
- Switch the machine off and bail the base out — A sponge and a cup will empty a sump in a few minutes and let you see it.
Tools: sponge, cupAbout 20 min
- Remove the filter, bail the sump and clear any debris — A sponge and a cup get the last of it out.
Tools: sponge, cupAbout 25 min
- Bail the base dry and check the sump for glass or stones — Wear gloves — glass chips are what usually get through.
Tools: gloves, sponge, torchAbout 30 min
- Clear the air gap cap and check the disposer spigot is open — Look for a moulded knockout plug still in place.
Tools: torchAbout 25 min
- STOP HERE before removing the pump or its housing — That means the machine out of its cabinet with the power and water off.
Before you open anything
Safety
Switch the machine off at its spur or breaker before removing any panel, and close the isolating valve before touching a hose. A capacitor can hold a charge after the power is off. Broken glass finds its way into the sump and the filter on any machine. Use gloves when clearing a filter, and never feel blind into a sump you cannot see the bottom of.
When to call a technician
Call once the filter and the sump are clear, the hose has its high loop, any air gap or disposer connection is open, and the water still will not leave. At that point the pump comes out. Call immediately if you smell burning from the base — a jammed pump motor can cook itself trying.
Nearest pages of this class
What this page does not cover
This page is written for the brand and the machine class, not for one family or model line. Where a family- or model-specific page exists for your machine, it is the more specific answer and it is where to start. Deliberately absent: programme charts, place settings, pump and board part identifiers and wiring colours, which differ between the freestanding, integrated and panel-ready families.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
