The short answer
A Caf CDD dishwasher that will not empty is either not being told to drain, not able to drain, or pumping into a blocked path. 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. Listening at the end of the cycle settles which: a pump that hums without moving water is a very different fault from silence.
What you can observe on these models
- 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.
- A hum at the drain step with no water movement — The pump is being driven but cannot turn, which is the signature of a jammed impeller or a solid blockage.
- Silence at the drain step — No pump drive at all — a control, a wiring or a pump motor fault rather than an obstruction.
- The sink gurgles while the dishwasher drains — The shared line is restricted, so the machine is pushing against a partly blocked disposer or trap.
- 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 — Ranked first because it is the classic new-installation failure: the drain hose is connected to a disposer whose knockout was never removed, so the machine has never had anywhere to pump.
- Filter and sump blocked with soil, glass or seeds — Second because it is reachable by hand from inside the tub and needs no tools on these models.
- Drain hose kinked or without its high loop — Third: a hose crushed behind the machine, or one that runs straight into the trap without rising, either blocks the flow or siphons water back.
- Drain pump impeller jammed — Fourth because it needs the power off and the sump opened, which is a step beyond the checks above.
- Drain pump motor, check valve or control — Last: silence at the drain step is the only symptom that points here first, and confirming it needs a meter.
Check in this order, and why
- Listen at the drain step — A hum with no water movement means a jam; silence means the pump is not being driven at all. That single sound splits the list.
- Scoop the standing water out — Nothing can be inspected under water, and the filter cannot be removed cleanly with a full tub.
- Clear the filter, then the sump, then the impeller — With the breaker off, each of these is a hand job on these models and they are in order of likelihood.
- Test-run a short cycle with the tub empty — A clean drain on an empty machine points back at soil load and filter maintenance rather than at a part.
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 CDD 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 CDD family
Reference| Model number | Family key |
|---|---|
| CDD220**W*** | caf:dishwasher:cdd |
| CDD42***T*** | caf:dishwasher:cdd |
When to call a technician
On the Caf CDD family everything up to and including the pump inlet is owner-reachable: the disposer, the air gap, the hose, the filter and the sump. Call when the drain step is silent, when the pump hums with a clear inlet, or when the fault returns within days of a full clean — those point at the pump, the check valve or the control. Call a plumber instead if the sink itself drains slowly.
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.
