The short answer
On the Black Decker WQP dishwasher water left standing at the end of a cycle is usually debris in the filter and sump rather than a failed pump. The WQP stems step through sizes on a common mechanism, so the sequence below holds across the whole model list.
What you observe
- Standing water in the base at the end of every cycle — A small film in the sump is normal on most builds; water above the filter after the cycle ends is not, and the amount left tells you whether it is a restriction or a stop.
- The pump runs and the water does not go — You can hear the drain pump working.
- No drain sound at all at the end of the cycle — Either the pump is jammed, or the cycle never reached the drain step.
- NEAR MISS — water on the floor rather than in the tub — That is a leak, not a drainage fault, and the leak page will get you there faster.
Causes, most likely first on the WQP family
- Filter and sump blockage — First on this family — the WQP stems step through sizes on a common mechanism — and a compact sump fills quickly: labels, seeds, glass and paper collect exactly where the drain path narrows. The pump then runs against a restriction and moves almost nothing.
- The drain pump impeller jammed by hard debris — Second and usually found in the same operation: a fragment of glass or a fruit stone stops the impeller, and the pump hums without moving water. Clearing it by hand often restores it completely.
- Drain hose kinked, trapped or without a high loop — Third. A hose crushed behind the machine or lying flat lets the waste run back in between cycles, which reads exactly like a machine that is not draining.
- The waste connection at the sink — Last, and the one that surprises people: a blocked sink trap, a shared waste under pressure or a new disposer with its blanking plug still fitted all stop a healthy machine dead.
Check in this order, and why
- Bail the tub and pull the filter — First and non-negotiable: you cannot judge anything downstream with the sump full, and the filter is the top cause.
- Inspect the pump inlet for hard debris — Second, with power off.
- Straighten the hose and confirm it rises before it falls — Third: a missing high loop produces the intermittent version of this fault, which is the one that gets misdiagnosed for months.
- Test the sink waste by filling and draining the sink — Last of the free checks: a slow sink is the appliance's problem too, and no part will fix it.
Before you open anything
Safety
Unplug the appliance or switch off its breaker before removing any panel or reaching into the sump — a capacitor can hold a charge after the power is off, and broken glass is the usual find down there. Wear a glove and use a torch rather than feeling blindly. Shut the water supply before disturbing a hose.
Models in the WQP family
Reference| Model number | Family key |
|---|---|
| WQP12-5901K-US | black-decker:dishwasher:wqp |
| WQP12-6502A | black-decker:dishwasher:wqp |
| WQP12-6503 | black-decker:dishwasher:wqp |
| WQP6-3603-US | black-decker:dishwasher:wqp |
| WQP8-P7606F-US | black-decker:dishwasher:wqp |
When to call a technician
Call when the filter, sump and hose are clear, the sink drains freely, and the pump still will not move water — that is a pump replacement and it needs the machine out. Call sooner if the waste connection itself is blocked behind the cabinet or shared with plumbing you cannot isolate.
Other faults covered for the WQP family
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
