Bosch Dishwasher Not Cleaning Properly — Fix

What Does This Error Mean?

Dirty dishes from a Bosch dishwasher are almost always caused by blocked spray arm holes — clear them with a toothpick and rinse the arms under a tap. Also check that tall items or pot handles are not blocking the spray arms from rotating during the cycle. Using the wrong detergent, overloading, or a clogged filter also causes poor cleaning results.

Affected Models

Bosch 300 Series Dishwasher
Bosch 500 Series Dishwasher
Bosch 800 Series Dishwasher
Bosch SHPM88Z Series
Bosch Silence Plus Series

Common Causes

Spray arm holes blocked with limescale, food particles, or label fragments from new dishes
Items loaded too close together — water cannot reach all surfaces
Tall pot handles or baking trays blocking the upper or lower spray arm from rotating freely
Filter at the bottom of the tub clogged — dirty water recirculating over dishes
Water temperature too low — short or eco cycles sometimes underheat the water

How to Fix It

Clean the spray arms

Remove the upper and lower spray arms (twist anti-clockwise or pull off, depending on the model). Use a toothpick to clear each hole. Rinse under running water and check that they spin freely when reinstalled.
Clean the filter

Remove the filter assembly at the bottom of the tub. Rinse the cylindrical filter and the flat mesh filter under running water. A clogged filter circulates dirty water over the dishes — it should be cleaned every 2–4 weeks.
Check your loading

Dishes must face the centre where the water pressure is highest. Do not nest bowls or cups. Pots and pans go in the lower rack facing down. Check that the spray arms spin freely after loading by rotating them by hand.
Use the correct detergent and quantity

Use a dishwasher-specific detergent tablet or powder — not liquid dish soap. Tablets are typically the most effective. Reduce the amount if you see excess foam; increase it for hard water or heavily soiled loads.
Run a hot cycle

Select a heavy or intensive programme at 65°C or higher. Eco cycles at 50°C can leave food residue on heavily soiled dishes. Running a hot empty cycle with dishwasher cleaner also dissolves grease and limescale from inside the machine.

When to Call a Professional

Poor cleaning that persists after all checks is usually a failing wash pump or a faulty heating element. A Bosch technician can test the pump pressure and water temperature during a cycle.

Frequently Asked Questions

Bosch dishwasher leaves food on the top rack only — why?

The upper spray arm is blocked or not spinning. Remove it and clear the spray holes, then confirm it clicks firmly back into place and spins freely.

Glasses come out cloudy after every Bosch dishwasher cycle — why?

Cloudy glasses are usually hard water etching (permanent) or a limescale film (removable). Check the rinse aid is filled and set to the correct level. If cloudiness comes off when you wipe with a damp cloth, it is removable limescale.

Bosch dishwasher leaves gritty residue on dishes — what is it?

Gritty residue is broken-down food that the spray arms are redistributing instead of flushing away. Clean the filter immediately — this is the primary cause. Also scrape plates before loading.