The short answer
Water left in the tub on the Caf PDT family usually means an obstruction, and the obstruction is usually reachable: the filter and sump first, then the pump impeller, then the hose. The matrix below lists two model tags that differ only in their trailing revision characters, so a part that suits one usually suits its neighbours, and the tag still decides. A small amount of water in the sump well at the end of every cycle is normal and is not a fault.
What you can observe on these models
- Draining works after the filter is cleaned and then stops again — Soil is reaching the pump because the filter is not retaining it, so the blockage rebuilds every few loads.
- A cycle that stops part way with water in the tub — The control aborted rather than finished, so treat it as a cycle fault with a drainage symptom.
- Glass or a fruit stone visible in the sump — The direct cause, and the reason a drain fault can appear overnight on a machine that was fine.
- Dirty water standing in the tub at the end of the cycle — The wash completed and the drain did not. That points at the drain path rather than at the wash system.
- NEAR MISS — water on the floor rather than in the tub — That is a leak, and the leak page covers it. A machine can leak and drain perfectly well at the same time.
Causes, most likely first on this family
- Disposer knockout plug or a blocked disposer — First on any machine that has just been installed or had a disposer fitted — the symptom is total and immediate.
- Filter and sump blocked with soil, glass or seeds — Second: the filter is the intended trap, and when it overflows the debris reaches the pump inlet and stops it.
- Drain hose kinked or without its high loop — Third, and the cause to suspect after any move, floor replacement or cabinet work.
- Drain pump impeller jammed — Fourth: a jam produces the hum-without-flow signature, and the object is usually glass or a fruit stone that passed the filter.
- Drain pump motor, check valve or control — Last on this platform, and the point at which the diagnosis stops being an owner job.
Check in this order, and why
- Confirm the cycle actually reached the drain step — A cycle that aborted early leaves water behind without any drainage fault existing at all.
- Inspect the disposer connection for the knockout plug — On a recent installation this is the first thing to check and the fault is total until it is removed.
- Clear the filter and inspect for glass — Use a gloved hand. Glass in the sump is both the cause and the reason to be careful about how you clear it.
- Straighten and re-loop the drain hose — Give it the rise it needs behind the cabinet so the tub cannot siphon back after a good drain.
Before you open anything
Safety
Switch the dishwasher off at its breaker before reaching into the sump or removing the filter — a capacitor can hold a charge after the power is off. Standing water in the tub hides broken glass on the Caf PDT family, so scoop it out and use a gloved hand rather than bare fingers at the pump inlet. Never run a cycle with the filter or sump cover removed.
Models in the PDT family
Reference| Model number | Family key |
|---|---|
| PDT75***R*** (v7) | caf:dishwasher:pdt |
| PDT755**V*** | caf:dishwasher:pdt |
When to call a technician
Call once the obstruction cannot be found in the filter, the sump or the hose, because what remains is a pump or control diagnosis with a meter. Call sooner if the machine trips its breaker during the drain step or if water is coming up into the sink rather than going out. Both are faults that get worse with repeated cycles.
Other faults covered for this family
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
