The answer, before the detail
Dirty dishes out of a Black+Decker WQP dishwasher usually mean one of three things — the arms are not reaching, the water is not hot enough, or the detergent is not being released. On this family the arms come first, because the jets are the part that silts up and the part you can inspect in under a minute. Settle the build before the ranking applies: these models divide on an air gap cap on the worktop.
What the owner actually sees
- Gritty deposits left on plates and in cups — It is often worse on the upturned items in the top rack.
- A cloudy film on glassware — A water hardness and detergent reading rather than a mechanical one.
- The cup has opened but the tablet has not dissolved — Either the cup is blocked by a tall item or the water is not warm enough to dissolve it.
- One rack consistently worse than the other — Swap a few items between racks to confirm the pattern.
- An arm that catches or stops against the load — An arm that cannot turn cleans a stripe and misses everything else.
- NEAR MISS — dishes come out clean but wet — That is a drying and rinse-aid question rather than a wash fault, and a different page.
Most likely first on this family
- The water arriving is not hot enough — It climbs to the top where the machine is a long pipe run from the water heater, because the cycle fills with whatever is in the pipe at that moment.
- The filter or the sump is loaded with debris — Second on filter builds and effectively absent on grinder builds, which is why the first thing to establish is which one you have.
- The spray arms are blocked, clogged or held by the load — It is placed here because it costs little to rule out and rules out more than it costs.
- Detergent type, dosing or a blocked dispenser — Mid-list, but it moves to the top when the complaint is film rather than grit, and in hard-water areas generally.
- The wash pump, its impeller or the chopper — Last of the five, because everything above it is cheaper and far likelier, and because this is the only one that needs a technician.
Check in this order, and why
- Spin both spray arms by hand — They should swing freely with the racks in place; hold one up to the light and look for closed jets.
- Check the filter and sump for debris — Rinse under a tap rather than scraping it.
- Check what temperature the fill actually gets — This is the free test for the temperature cause.
- Look at what is left in the dispenser at the end — A tablet still sitting there names either the cup or the water temperature.
- Reload the racks and run the same load again — The cheapest experiment on the list.
Power off first
Safety
Switch the machine off at its breaker before reaching behind the kick plate or the door panel — water and mains wiring share the same small space in a dishwasher, and a capacitor can hold a charge after the power is off. Leave the door latch and its switch exactly as they are: the machine is meant to stop the moment the door opens.
When to call a technician
Call when the arms spin freely with open jets, the filter is clean, the fill is hot and the detergent dissolves — and the dishes still come out dirty. That leaves the wash pump, the impeller or the chopper, and none of those are reachable without taking the machine out. Call sooner if the cycle sounds different from the way it used to, because a pump losing pressure usually changes its note.
Other faults covered for the WQP models
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
