The short answer
Standing water in the tub at the end of a cycle is a blockage far more often than a failed pump. On a professional built-in cabinet the ranking below starts at the filter and the drain hose because that is where the obstruction usually is and because both are owner-clearable.
What you observe
- A smell from the tub between uses — Standing water and trapped soil, which is the same fault seen a few days later.
- Water standing in the bottom of the tub after the cycle — The core symptom, and it means the water never left.
- NEAR MISS: a small amount of clean water in the sump between cycles — Many machines keep a little water in the sump by design to stop the seals drying out.
Causes, most likely first on this appliance
- The filter and sump are blocked — Soil, labels, seeds and broken glass collect in the sump and block the drain path. Ranked first on DCS: these machines are integrated, levelled against a hard counter and plumbed behind a panel, so the installation carries more of the fault load than the machine does, and a heavy professional cabinet installed to tight tolerances has less room for error than its build quality suggests.
- A kinked or blocked drain hose — The hose behind or under the machine gets crushed when the machine is pushed back, and it collects grease over time. Ranked second: it ranks here because the causes above it are free to check and this one is not.
- No high loop or air gap in the drain hose — Without a high loop the waste drains back into the machine, so the tub is never actually empty. Ranked third: it sits here because on a built-in unit it is a real cause, but reaching it means disturbing the installation.
- The drain pump itself — An impeller jammed by glass or a label, or a pump that has failed. Ranked last: it is last because these components are built to a long service life, and because confirming one needs instruments and a service manual that are not owner tools.
Check in this order, and why
- Take the filter out and look into the sump — A soil mat on the filter, or debris sitting in the sump well, explains a slow or failed drain immediately.
- Look at the hose run from the machine to the waste connection — A visible kink where the machine was pushed back is a free fix, and a hose that is soft and heavy with grease is a clean-out.
- Look at whether the hose rises before it falls to the waste — A hose that runs flat or downhill the whole way is an installation fault and it will keep producing this symptom.
What an owner can safely check
- Remove the filter, clear the sump by hand and rinse both — Bail the standing water out first, then lift the filter, clear the sump with a cloth, rinse the filter under a tap and refit it until it locks.
Tools: cloth, cup or jug, soft brushAbout 30 min
- Pull the machine forward carefully and straighten the drain hose — Look for crush points, take the kink out and leave the hose room so it is not pinched when the machine goes back.
Tools: torchAbout 25 min
- STOP HERE if the next step needs a meter on live terminals or a panel off — That is where an owner check ends and a service call begins.
Before you open anything
Safety
Switch the machine off at its breaker before reaching into the sump or moving the machine, and switch a waste disposer off at the wall before putting a hand anywhere near it. Expect broken glass in the sump and use a cloth rather than bare fingers.
When to call a technician
Call once the filter, the sump, the hose, the air gap and the waste connection are all proven clear and water still stands in the tub, because what is left is the pump or the control. Call a plumber rather than an appliance technician if the sink waste itself is slow, because the machine cannot drain into a blocked waste.
Nearest pages of this class
What this page does not cover
This page covers DCS as a family, not one model line. Where a page exists for the line named on your plate it is linked below and it is the more precise answer. Not here: the pump and filter part numbers, and the drain routing specified for your specific installation.
Links: - [DCS by Fisher & Paykel dishwasher not draining: causes ranked and what to clear first (the later DCS by Fisher & Paykel platform)](/blog/dcs-by-fisher-paykel-dishwasher-drainage-failure-2)
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
