Look at the pattern
If one area of the rack is consistently dirty, check for an obstructed spray arm or an item shielding that area. If a pack remains in the dispenser, look for a blocked dispenser door and follow the manual’s detergent instructions. White film is a different symptom from stuck food.
Record whether the problem began suddenly, followed a new detergent or occurs only with a particular load. A short note and photograph are useful if you later need service.
Check what you can safely maintain
Bosch’s troubleshooting guidance highlights filter cleanliness, spray-arm openings and adequate space between dishes. Apply your own model’s removal and cleaning instructions; not every filter assembly is designed to come apart in the same way.
Make sure the chosen program suits the load. A quick cycle intended for lighter soil may not be appropriate for dried cookware. Verify any supply-temperature requirement in the manual rather than changing the household water heater based on generic advice.
Know when to call
If the machine does not fill, reports a recurring fault, leaks or makes a new abnormal noise, use the manufacturer’s service route. Do not remove electrical panels or bypass a door switch to investigate a wash problem.
After a safe maintenance check, run a representative load with ordinary spacing and the correct detergent dose. Change one variable at a time. If results remain poor, provide the technician with the exact model, error code and steps already taken.