The short answer
On the SMI dishwashers in the table below, a load that comes out gritty or still wet is almost always the wash water, not the machine: a loaded filter, a spray arm that cannot turn, or an empty rinse-aid cup. The four codes in the table share the family stem and sit close together in build, so the layout described here holds across them.
What you observe on these models
- Grit on the lower rack while the upper rack is clean — The two racks are fed by different spray arms. A clean top and a dirty bottom points at the lower arm — blocked jets, or an arm that a pan handle stopped from turning.
- Everything comes out wet, plastics worst of all — Plastic holds the least heat, so it dries last on any dishwasher that dries by condensation rather than with an exposed element.
- A white chalky film on glassware — Wipe a glass with a little vinegar. If the film lifts, it is mineral deposit — hard water with too little detergent or no rinse aid.
- NEAR MISS — water standing in the bottom at the end of the cycle — That is drainage, not washing, and it belongs to the drainage page for this family.
Causes, most likely first on the SMI family
- The filter assembly and sump screen are loaded with soil — Ranked first because it is both the most common cause and the only one you can settle in a minute: twist the filter out, hold it to a light, and you either see daylight through the mesh or you have found your fault.
- A spray arm is blocked, or the load stopped it turning — Second, and on a family this narrow it is the cause that moves up: a tall item on the lower rack catching the upper arm is the single most common non-part reason for a bad wash, and nothing about the machine is wrong when it happens.
- Rinse aid is empty, or the dispenser setting is too low — Ranked here because it answers the "wet dishes" half of the complaint completely, and because a new installation is the commonest time for the cup to have never been filled at all.
- The load is shadowing itself — It ranks this high on a narrow family because the machine is usually new, the household is still learning the rack layout, and the pattern of what comes out dirty is nearly always the pattern of what was shadowed.
- The heating circuit or its sensor has failed — Last. On a family represented by so few codes the units in service are generally young, which pushes a failed heating circuit further down than the brand-generic article puts it.
Check in this order, and why
- Pull the filter and look through it — It twists out by hand, no tool. Hold it to a light: if the mesh is blind, rinse it under a hot tap with a soft brush and run one short cycle empty before you judge anything else.
- Spin both spray arms by hand, then check their jets — They should turn freely through a full circle with the racks in place.
- Open the rinse-aid cup and the detergent cup — Fill the rinse aid if it is empty; note whether the detergent cup shows residue from the last cycle, which tells you the dispenser did not open or the water was cold.
- Reload the racks and run the same load again — Nothing over the dispenser, nothing lying flat, cutlery alternated. A wash that comes out clean on the second run was never a machine fault.
- Only now judge the heating circuit — If the filter is clear, the arms turn, the rinse aid is full and hot water is arriving, and the load is still wet and dirty, the heating circuit is the remaining candidate and it is a service call.
Models in the SMI family — Each code here is pinned to a single build, so match the tag inside your door frame character for character. The four codes fall into four leading groups, and that spread is the reason this page is written for the family rather than for one machine.
Reference| Model number | Family key |
|---|---|
| SMI4HTS01A | bosch:dishwasher:smi |
| SMI6HCS01A | bosch:dishwasher:smi |
| SMI88TS01A | bosch:dishwasher:smi |
| SMI8ZCS02A | bosch:dishwasher:smi |
Before you open anything
Safety
Switch off the breaker before removing the toe-kick or the access panel; a capacitor can hold a charge after the power is off. Treat the sump as sharp — glass chips collect there and are invisible under water.
When to call a technician
The line on this family is the toe-kick. Everything above it — filter, arms, dispenser, racks, the supply valve under the sink — is an owner job that needs no tool and no part.
Sources — The symptom-report corpus recorded in this snapshot is what put this symptom on the page for this brand and appliance.
Documented- amazon-reviews — amazon-reviews, fetched 2026-09-02
Other symptoms covered for this family
SC
Sarah Chen
Lead Appliance Repair Technician · 12 years experience
EPA 608 UniversalNASTeC Certified
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
