The short answer
This page covers the Bosch SMS-series dishwasher on the level below the brand-generic article, so it starts where that one stops: with what the full-width cabinet and its own worktop 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 front-face controls decide which of the remaining causes is worth your next five minutes.
What you observe
- A chalky white haze on glassware — Minerals rather than soil, and on these models the water treatment is the thing to look at before the wash mechanics.
- Detergent still sitting in the dispenser at the end — The door never opened, or opened against something leaning on it.
- One rack clean and the other not — A spray pattern problem rather than a wash-quality problem, and the two are diagnosed differently.
- 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
- 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. First, because on these models it is the one cause that gets worse every cycle it is ignored.
- 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. Second on these models: it is invisible unless you look at the cup at the end of a cycle.
- 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. Third on this family - usually obvious once the racks come out.
- 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 comes last here - a slow cause, and it shows as haze long before it shows as grit.
- Where this ranking departs from the brand-generic page — The cause that moves is a blocked filter in the tub floor. It leads on this family because the machine has its own worktop and is usually plumbed into a run that was already there. 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
- 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.
- 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.
- 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
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Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
