The short answer
On the Black Decker BDW dishwasher a load that comes out dirty is usually water that cannot clean rather than water that is not arriving. The BDW list is a ladder of sizes on one mechanism, so the sequence below applies across the model list in the table.
What you observe
- A gritty film on everything, top rack and bottom alike — Uniform across the load.
- Clean at the front, dirty at the back — or the reverse — A pattern is the most useful thing a bad wash can give you: it maps directly onto where the spray is not reaching.
- Food debris redeposited on the upturned faces of bowls — The filter is passing what it caught back into the wash, which is a filter and sump problem before it is anything else.
- NEAR MISS — dishes are wet as well as dirty — A load that does not dry either points at the heat and the cycle itself, and the heating page will take you further than this one.
Causes, most likely first on the BDW family
- Water temperature at the point of fill — First on this family — the BDW list is a ladder of sizes on one mechanism — and a small chamber holds very little water, so it depends heavily on what arrives already hot. A long cold run of pipe between the heater and the machine is the most common invisible cause of a whole-load film.
- Detergent type, dose and where it is placed — Second: a tablet dropped loose into the base dissolves in the pre-wash and is gone before the main one, and an old or damp box loses its enzymes entirely. Both produce a uniformly poor load with no pattern at all.
- Hard water, rinse aid and any salt the build takes — Third, and the cause behind most cloudy glassware. It does not vary from load to load, which is how you separate it from the mechanical causes.
- Spray arms, filter and loading — Last on this ranking. These leave a pattern in the load rather than an even film, so when the whole rack is equally bad they are rarely the answer — but they are always worth clearing before spending on chemistry.
Check in this order, and why
- Judge the load: even film or a pattern? — First, because this one observation sorts the entire list.
- Run the sink tap hot, then start the machine — Second: if one load improves dramatically, the supply run was the fault and no part needed buying.
- Change detergent and place it in the dispenser only — Third — cheap, fast, and it settles a large share of these complaints on its own.
- Now clean the filter and spin the arms — Last on this ranking, though it remains worth doing on every machine: with chemistry ruled out, a blocked arm means what it says.
Before you open anything
Safety
Unplug the appliance or switch off its breaker before removing any panel — a capacitor can hold a charge after the power is off. Shut the water supply before disturbing a hose or a coupler. Wash water is hot enough to scald, so let a cycle finish before opening a door fully, and never reach into a sump without power off: broken glass is the usual find there.
Models in the BDW family
Reference| Model number | Family key |
|---|---|
| BDW100M* | black-decker:dishwasher:bdw |
| BDW200M* | black-decker:dishwasher:bdw |
| BDW300MHS | black-decker:dishwasher:bdw |
| BDW400MS | black-decker:dishwasher:bdw |
| BDW500MHS | black-decker:dishwasher:bdw |
When to call a technician
Call when the arms spin freely, the filter is clean, the supply is hot and the load still comes out under-washed — at that point the wash pump or its seal is the remaining suspect and it needs the machine out and on its back. Call sooner if you find water under the unit while investigating, or if the sump is full of broken glass.
Other faults covered for the BDW family
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
