The short answer
When the Caf CDT family stops draining, work from the sink back to the machine rather than the other way round. With eight model tags in the matrix below, this family covers several passes of the same platform, and a cause that is a running change on one group can be absent on another. The disposer, the air gap and the hose loop are all outside the cabinet, and checking them first avoids pulling out a machine that was never at fault.
What you can observe on these models
- Water backs up out of the air gap on the sink deck — The line between the air gap and the disposer is blocked, which is a plumbing fix rather than an appliance one.
- Clean water rather than dirty water left behind — That is a fill-after-drain pattern: the machine drained and then took water on, which points at the inlet valve, not the pump.
- 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.
- NEAR MISS — a little water in the sump well every time — A small residual in the well is by design; it keeps the seals wet. Only a covered tub floor counts as a drainage failure.
Causes, most likely first on this family
- Drain hose loop lost or crushed behind the cabinet — First on a machine that was recently moved or refitted: the hose is the part most often damaged by pushing the appliance back into its housing.
- Sink-side blockage — disposer, trap or air gap — Second, and the check that stops a plumbing problem from being treated as an appliance one.
- Filter and sump soil load — Third: still the commonest cause overall, and it takes minutes, so do it even when another cause looks likely.
- Impeller jam at the drain pump — Fourth, and the last of the owner-reachable causes on these models.
- Pump motor or check valve failure — Last: a genuine failure of the pump is real but uncommon, and the causes above imitate it well enough to waste a part.
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
Power down at the breaker before the sump cover comes off; a capacitor can hold a charge after the power is off. Dirty standing water is a hygiene hazard as much as an electrical one — scoop it into a bucket rather than bailing it onto the floor, and wash hands and tools afterwards. The heating element in the tub floor may still be hot.
Models in the CDT family
Reference| Model number | Family key |
|---|---|
| CDT800**N*** | caf:dishwasher:cdt |
| CDT805**N*** | caf:dishwasher:cdt |
| CDT828**V*** | caf:dishwasher:cdt |
| CDT84***N*** | caf:dishwasher:cdt |
| CDT858**V*** | caf:dishwasher:cdt |
| CDT858**Z*** | caf:dishwasher:cdt |
| CDT87***N*** | caf:dishwasher:cdt |
| CDT888**V*** | caf:dishwasher:cdt |
When to call a technician
Scooping, filtering and hose routing are yours. Call for anything that needs the pump removed, the check valve replaced or the control condemned on these models. Call the same day if dirty water has reached the floor and run under the cabinet — the drainage repair is small and the cabinet damage is not.
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.
