The short answer
Water standing in the BS tub at the end of a cycle is a drain-path problem, and on this family the path is short: filter well, drain pump, then the hose up to the air gap or disposer spigot. The brand-generic page starts at the pump; here the filter well and the check valve above it are what block first.
What you observe
- Standing water covering the filter at cycle end — A shallow film over the sump is normal; water above the filter rim is not.
- The machine hums at the drain step but the level does not fall — The pump is being asked to run and cannot move water, which points at a blockage rather than a dead motor.
- Drain noise that stops early — A pump that changes note and quits part way through usually has debris in the impeller.
- Water backing up from the sink side — A shared waste, a blocked disposer spigot or a sink blockage can push water back into the tub.
- NEAR MISS - the tub is dry but the dishes are dirty — That is a wash-flow fault and belongs on the cleaning page instead.
Causes, most likely first on BS
- Debris in the filter well and check valve — Ranked first on the BS family: a deeper professional sump still funnels everything into one narrow outlet, and that outlet is where a blockage sits. That is a family-level property rather than a model-level one, which is why it leads here and not on a page about one machine. What moves against the brand-generic order is lower down: kinked drain hose or a missing high loop sits above blocked disposer spigot or air gap here, because this family is a single build with fixed access points.
- Blocked or jammed drain pump impeller — Second: the pump is sized for a long cycle rather than a violent one, so it stalls against debris rather than clearing it.
- Kinked drain hose or a missing high loop — Third: a heavy machine pushed back into its recess can crush the hose against the wall without leaving a mark.
- Blocked disposer spigot or air gap — Fourth: these installations frequently share a waste with a second appliance, so the shared branch is the thing to check.
- Drain pump motor or its control failure — Last: last, and the only item here that is not owner work on a built-in machine.
Check in this order, and why
- Bail out the standing water and lift the filter stack — You cannot inspect anything under water, and the filter well is the first place debris lands.
- Check the impeller for debris with the power off — Isolate first. A fragment of glass or a label wrapped on the impeller is the common find.
- Check whether the machine ever drained since the last kitchen change — A machine that has never drained since an install points at the spigot plug, not at wear.
- Check the disposer spigot or air gap — Especially worth it if the machine has never drained since a recent kitchen change.
Before you open anything
Safety
Kill the power at the breaker and the water at the stop tap before anything comes apart, and leave the door interlock alone: it exists so the machine cannot spray with the door open.
When to call a technician
The filter well and the hose run are owner work. Call when the pump itself will not run with a clear path, or when the machine has to come out of the cabinet to reach the hose, because the supply and waste are made up behind it.
Other BS pages
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
