The short answer
A dishwasher that has stopped cleaning is usually being starved of water, heat or spray rather than failing mechanically. On a professional built-in cabinet the ranking below starts with the filter and the spray arms because they account for most of these complaints and both are free to deal with.
What you observe
- A white film on glassware — A water hardness and detergent question rather than a mechanical fault.
- Baked-on soil that will not shift — Usually cold water rather than weak spray, so the heat side is the place to look.
- NEAR MISS: dishes clean but still wet — That is a drying complaint, which is about rinse aid and the final rinse temperature rather than about cleaning.
Causes, most likely first on this appliance
- Spray arms that are blocked or not turning — Soil and scale plug the jets, and a tall item in the rack stops the arm turning at all. Ranked first on DCS by Fisher & Paykel: 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 the parent-platform controls behave like their own family rather than like the styling on the front.
- Water arriving too cool — A machine fed from a long cold run, or one whose heating element is weak, washes in water that will not shift grease. Ranked second: it is placed here because it is the point where an owner check turns into a service call.
- A clogged filter — The filter at the bottom of the tub catches soil so it is not sprayed back onto the dishes. Ranked third: it ranks here because the causes above it are free to check and this one is not.
- A weak circulation pump — The cause left once the filter, arms, load, detergent and temperature are all clean. 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
- Spin each arm by hand and check the jets — An arm that catches, or holes you can see are blocked, is the cause and it is clearable at the sink.
- Run the kitchen tap hot before starting the machine — A cycle that cleans better after the tap has been run hot tells you the supply temperature was the issue.
- Take the filter out and look at it — A filter with a soil mat across it explains gritty dishes on its own, and no other check is worth doing before this one.
What an owner can safely check
- Remove the spray arms, clear every jet and refit them — Unclip each arm, push a cocktail stick through any blocked jet, rinse them out and refit.
Tools: cocktail stickAbout 20 min
- Run the hot tap at the sink until it is hot, then start the machine — This fills the machine with hot water from the first fill rather than the cold slug sitting in the pipe.
About 10 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 removing anything below the lower rack, and keep it off while your hands are inside. Expect broken glass and sharp soil in the filter and the sump: use a cloth rather than bare fingers.
When to call a technician
Call once the filter, the spray arms, the load, the detergent and the supply temperature have all been addressed and the machine still washes poorly, because what is left is the pump, the heater or the inlet valve. Call sooner if the machine no longer sounds like it is spraying at all, or if the tub is not draining between phases.
Nearest pages of this class
What this page does not cover
This page covers the DCS by Fisher & Paykel dishwasher as a class, not one model or production run. Any family- or model-specific page for your unit takes precedence over it. Not here: the filter assembly and spray arm part numbers, and the cycle temperatures for your specific machine, which vary by model.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
