The short answer
On a Bosch dishwasher, a full cycle that leaves the load dirty or wet most often traces back to water that is not hot enough arriving rather than to hard water film and scale. A machine this common has usually been worked on before, and that matters more than the badge: if a part has been changed or a hose re-fitted at some point, the previous repair belongs near the top of the list. Work down the order rather than across the list — the ranking is the page, and the cheapest answer arrives first.
What you are seeing
- The same area of the rack is dirty every time — A zone failing repeatedly is geometry: an arm or a blockage.
- Grit on everything after a full cycle — Washing in its own filtered water means the filter is the first suspect.
- Cloudy glassware with no food on it — White film rather than residue points at water hardness.
- NEAR MISS — the cycle never finishes — A machine that stalls is a different fault and a different page.
Why this happens, in order of likelihood on Bosch
- Water that is not hot enough arriving — Greasy film on everything, rather than patches of dirt, is the signature. It is a plumbing condition rather than an appliance fault and it responds to a simple habit. First here because it costs nothing to rule out, and every check below it is unreliable while it is open.
- Spray arms that cannot turn or cannot spray — The pattern names it: the same area comes out dirty every time, while the rest is fine. That is geometry, not chemistry, and it is the first thing to check. Second here, close enough behind the first that both are usually checked in the same minute.
- A previous repair on a much-serviced platform — A machine this widely sold has a parts supply behind it, which is a good thing and also means it gets fixed by many different hands. Placed here for what kind of machine this is rather than for a part: a previous repair is not the first candidate on this symptom, but it is the one that explains the cases that fit nothing else.
- A filter that is not being cleaned — Grit on the dishes after a full cycle, and a smell from the machine, are the two symptoms that arrive together here. Fourth on this brand, and mostly here because it is so often misdiagnosed as the cause above it.
- Hard water film and scale — In a hard-water area, scale builds on the heater, the arms and the jets, and leaves a cloudy film on glass that looks like poor washing. Last, deliberately: the least likely cause here and the one that is not owner work.
The order to work in
- First: Run the kitchen tap hot before starting the machine — It leads the order because the test is free and it explains the whole-load cases that the arms do not.
- Second: Spin each arm by hand and look through the jets — Second because a whole zone failing is the most common complaint and the check is free.
- Third: Ask what was last done to this machine — It comes last because the answer is free and because a repair carried out recently is the strongest single predictor of where to look.
Owner-side checks, step by step
- Run the hot tap at the sink until it is hot, then start the cycle — Let the tap run until the water is properly hot so the machine draws hot water on its first fill.
About 10 min
- Spin each spray arm by hand and clear the jets — Turn each arm through a full circle to check nothing blocks it, then clear the holes with a cocktail stick and rinse.
Tools: cocktail stickAbout 20 min
- STOP HERE if the next step needs a meter on live terminals — That is the line between an owner check and a service call, and it is not worth crossing.
Safety first
Safety
Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off. A built-in dishwasher usually has no reachable plug, so isolate it at the breaker and at any switch under the sink. Close the supply valve before undoing a fitting, and treat the water inside as hot.
Where owner work ends
The owner side ends at the checks above: no tools, no panel off, no meter. Anything that needs the machine pulled out of its housing, or a meter on live terminals, is where owner work ends. Call sooner if the fault is getting worse rather than staying the same, because a cheap cause left alone is how an expensive one arrives.
Nearest pages of this class
What is deliberately not on this page
What this page does not do is speak for one family or one model. It covers Bosch dishwashers generally, and no family-specific page exists for it yet to send you to — when one is published, this page will link down to it and defer to it. Also absent by choice: part numbers, wiring detail and dismantling order.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
