The short answer
This page covers the Bosch SMI-series dishwasher on the level below the brand-generic article, so it starts where that one stops: with what the full-width cabinet and a fully integrated door do to a poor wash. The brand answer is the filter, and it is not wrong; what changes here is everything after it, because the softener reservoir and top-edge controls decide which of the remaining causes is worth your next five minutes.
What you observe
- One rack clean and the other not — A spray pattern problem rather than a wash-quality problem, and the two are diagnosed differently.
- Grease rather than grit left behind — That points at wash temperature and detergent rather than at anything blocked.
- A gritty film on everything, worst on the lower rack — The machine washed with water it never cleaned, and the lower rack takes the most of it.
- NEAR MISS - dishes come out clean but wet — Condensation drying working as designed. Rinse aid and a few minutes with the door ajar are the answer, and there is no fault here to chase.
Likeliest causes here
- The detergent dispenser blocked or opening late — A tall item leaning on the flap means the detergent lands at the wrong moment, or never leaves the cup at all. It leads here, and not by default: it is invisible unless you look at the cup at the end of a cycle.
- Scale on the element, in the arms and across the sump — Hard water leaves a deposit that closes jets, insulates the element and roughens every surface soil can cling to. It sits second on this family because this platform carries a water-treatment part that owners forget exists.
- A blocked filter in the tub floor — The filter is meant to be twisted out and rinsed by the owner, and a machine that has not had that done recirculates the same soil for a whole cycle. Third here. Worth ruling out even when something else looks more likely.
- Spray arm jets closed up, or an arm that cannot turn — Scale and debris shut the small holes, and a handle through the rack stops an arm dead where it stands. Last on this family, and deliberately so: usually obvious once the racks come out.
- Where this ranking departs from the brand-generic page — The cause that moves is the detergent dispenser blocked or opening late. It leads on this family because the controls sit on the top edge of the door and vanish the moment it closes. That is a property of the platform rather than of the brand, which is why the page above this one cannot rank it the same way.
Check in this order
- Run a cycle and open the door the moment it ends — Detergent still in the cup is a loading problem far more often than a mechanical one. It leads on these models because the construction puts it within reach before anything else on the list.
- Feel the inside of the door and the element for a gritty film — Scale you can feel with a fingertip is enough to change how this machine washes.
- Twist the filter assembly out and rinse it under a tap — Look at what comes out of it. A filter that has never been cleaned is both the diagnosis and the repair.
- Spin each arm by hand and hold it up to the light — Every jet should pass light, and nothing in the racks should foul the arm through a full turn.
Before you open anything
Safety
Switch the machine off at its breaker before reaching under the tub - unplug the appliance or switch off its breaker before removing any panel, because a capacitor can hold a charge after the power is off. Assume broken glass anywhere near the filter, and let the sump cool before putting a hand in it after a hot cycle.
When to call
On these models the owner's ground is the filter, the arms, the dispenser, the rinse aid well and the rack arrangement, all of it reachable with the machine where it stands. Call once those are clean and the wash is still poor: what is left is wash pressure, the diverter and the heating circuit, and all three are diagnosed with the machine running and panels off.
Nearest pages
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
