The short answer
On a Miele dishwasher, the first thing to check is a loaded filter and sump. Water standing in the tub at the end of a cycle is a blocked path far more often than a failed pump. Miele dishwashers are engineered for a long service life with a drain pump behind the toe panel and a filter the owner is expected to lift out and rinse, so most drainage faults here are maintenance, not failure. Clear the sump and the air gap first: between them they account for most of what technicians find on this complaint.
What you observe
- Water stands above the filter when the cycle ends — Enough to cover the sump and reach the bottom of the door is a real drainage fault.
- Dishes come out with debris settled on them — Dirty water that never left is being carried into the next stage of the cycle.
- The machine hums at the drain step and nothing moves — The pump is being asked to run against a block, which is a clue about where the block is.
- NEAR MISS - a small puddle in the sump recess only — A shallow film of water around the filter is normal on most machines and seals the sump.
Causes, most likely first on Miele
- A loaded filter and sump — Debris settles in the sump and packs around the filter until the pump cannot pull water through it. Ranked first because it is owner maintenance nobody remembers doing, and it blocks the drain path before it blocks anything else. On Miele, the machine is built for a long service life with an owner-serviceable filter, so drainage faults here are maintenance far more often than failure.
- A blocked air gap or a kinked drain hose — The air gap on the sink deck clogs with the same debris as the sump, and a drain hose crushed behind the machine after an installation does the same thing permanently. Ranked second because it sits outside the machine, so it is invisible until someone looks for it.
- A disposer knockout plug or a blocked disposer — When a dishwasher drains into a food-waste disposer, the disposer inlet knockout has to be removed at installation. Ranked third because on a new installation it is the single most common cause, and it costs nothing to check.
Check in this order, and why
- Lift out the filter and clear the sump by hand — It is the first thing a technician does and it frequently ends the visit. It comes first because the ranking above puts a loaded filter and sump ahead of everything else on this platform.
- Lift the air gap cover on the sink deck and look inside — If water spills from it during a cycle, the restriction is downstream of it.
- Run the disposer for a few seconds and try again — A full disposer blocks the dishwasher drain as effectively as a plugged hose.
What an owner can safely check
- Bail the standing water, then lift and clean the filter stack — Scoop the water out with a cup and a towel, twist the filter free, rinse it under a hot tap, and clear whatever has packed into the sump underneath.
Tools: cup, towelsAbout 20 min
- Clean the air gap and check the hose behind the machine — Twist off the chrome cover and the plastic cap, clear any debris with a bottle brush, refit, and look behind the machine for a hose that has been crushed against the wall.
Tools: bottle brushAbout 15 min
- STOP HERE if the next check needs a meter on live terminals — Everything past this point is measured with power applied, and that is where an owner check ends and a service call begins.
Before you open anything
Safety
Switch the machine off at the breaker before you put a hand in the sump - a capacitor can hold a charge after the power is off. Assume there is broken glass in the standing water, because there often is, and scoop with a cup rather than reaching in. Standing water from a wash cycle is not clean water: keep it away from children and pets while you work.
When to call a technician
Call once the filter, the sump, the air gap, the hose and the disposer are all proven clear and water still stands - that puts the fault at the pump or the control, where a meter is needed. Call sooner if the machine trips the breaker during the drain step, or if clearing the sump produces water at the cabinet floor, because that is a second fault.
Nearest pages of this class
What this page does not cover
This page covers the Miele dishwasher as a class, not one family or one model line. What changes from build to build - wiring colours, part numbers and component test values - is deliberately absent. Where your model plate names a line, use that line's documentation first.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
