The short answer
The usual answer on this unit is detergent type, dose or age, and no rinse aid, with a filter and sump full of debris next. Both are about water not reaching the soil, and neither needs a part. Everything above the last cause is owner work with no tools and no panel off.
What you actually observe
- The top rack cleans and the bottom does not, or the reverse — One spray arm is not getting its share of the water.
- The cycle sounds quieter than it used to — A spray arm that is not turning makes less noise, and that is a real clue.
- NEAR MISS: there is standing water in the bottom at the end — That is a drainage fault and belongs on the drainage page for this unit.
Causes, most likely first on this unit
- Detergent type, dose or age, and no rinse aid — Tablets that have absorbed damp, a dispenser loaded for a short cycle, or a machine run without rinse aid in hard water all give exactly this result with nothing broken. Ranked first on this unit: it is the variable that changes weekly without anyone thinking of it as a change, which counts for more here because this is a nameplate you will not find a service bulletin for, so the ranking below is built from the failure modes of the class rather than from a model-specific note.
- A filter and sump full of debris — The filter under the lower arm catches food soil so it is not sprayed back. Second: it is a consumable maintenance job that is not mentioned at the point of sale, so most machines have never had it done.
- Spray arm holes blocked with scale or debris — The jets are small and they block from the inside with grit and from the outside with scale. Third: in a hard-water area it happens to every machine eventually, and it produces exactly this slow decline rather than a sudden failure.
- A weak wash pump or a stuck diverter valve — The pump makes the pressure and the diverter shares it between the arms. Last on purpose: everything above it produces the same dirty dishes for nothing, and this one is the only parts job on the list.
Check in this order, and why
- Check the detergent is fresh, correctly dosed, and that rinse aid is topped up — Cheapest test on the page: one load with fresh detergent answers it.
- Twist out the filter under the lower spray arm and look at it — If it is packed, you have found both the grit and the poor cleaning.
- Take the arms off and hold them up to the light — Blocked jets are obvious once the arm is off the machine.
What an owner can safely check
- Fit a fresh tablet from a sealed pack, fill the rinse aid, and run a normal load — Damp tablets are a genuine and very common cause.
About 10 min
- Twist out the filter assembly, wash it under a hot tap with a brush, and clear the sump beneath it — Refit it and check it locks: a filter left loose lets debris straight into the pump.
Tools: a washing-up brushAbout 20 min
- STOP HERE if the next step needs a meter on live terminals — That is where an owner check ends and a service call begins.
Safety first, and it is not boilerplate
Safety
Kill the power at the breaker, or unplug the machine, before a panel comes off, and close the supply valve under the sink before you touch a hose. The element in the sump holds heat long after a cycle ends, so give it time before you reach in. Never run the machine with its kick plate off, and never wedge a door latch to make a cycle start.
Where an owner check ends
Call once the filter is clean, the arms turn freely and spray properly, the detergent is fresh and the water is arriving hot, because at that point the machine is not making pressure. Call sooner if you see water outside the machine or it trips a breaker.
Related pages for this unit
What this page does not cover
This page covers the Walsh dishwasher as a class, not one family or model line. Where a family- or model-specific page exists it is linked here. Deliberately not here: pump part numbers, diverter test procedures and any wiring detail, all of which differ by family and belong on the page for that family.
Links: - [Water under a Walsh refrigerator, and where it comes from](/blog/walsh-refrigerator-water-leak) - [Why a Walsh refrigerator has stopped making ice](/blog/walsh-refrigerator-ice-production) - [Why a Whynter dishwasher is leaving dishes dirty](/blog/whynter-dishwasher-cleaning-performance)
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
