The short answer
On the GDBE line, the most common reason a dishwasher is not draining is drain pump impeller jammed. On this page that cause is ranked ahead of filter and sump blocked, which is where the order departs from the brand-generic article above; the ranking below says what about this platform moved it. Four of the five causes below are owner-checkable with no tools worth naming, and the last of them is a service call.
What you see on the GDBE line
- A humming from the pump with no water leaving — The pump is driven and the impeller is stopped.
- Dirty water rather than clean — Food soil left in the base means the filter is not doing its job either.
- Water appearing in the base between cycles — That is the sink draining back into the machine, which is a plumbing fault.
- A gurgle at the sink when the machine drains — The two share a drain, and a restriction there shows up at both.
- NEAR MISS — water on the floor — A leak is a different page.
Causes, most likely first on the GDBE line
- Drain pump impeller jammed — Glass fragments, olive stones and labels get past the filter and stop the impeller. The pump hums and moves nothing, which is the same signature as on a washer. It ranks at this level because the hum-without-flow pattern identifies it and because it is sometimes clearable from the sump. The GDBE key covers a single model, so nothing on this page has to be qualified across capacities or configurations.
- Filter and sump blocked — The filter assembly catches what comes off the plates, and once it packs the water cannot reach the pump at all. It lifts out by hand and it is meant to. It is the only part of the drain path meant to be cleaned by the owner.
- Air gap blocked — Where an air gap is fitted at the sink, it collects the same soil the filter does, and a blocked one stops the drain while looking entirely innocent on the counter. It belongs on the list because it is outside the machine and is therefore the last place anybody looks.
- Disposer knockout plug still fitted — When a dishwasher is plumbed into a new disposer, a plug inside the disposer inlet has to be knocked out first. Left in place, the machine cannot drain at all from its very first cycle. It ranks here because it is the whole answer on a recently installed machine and is invisible from outside.
- Drain pump failed electrically — A pump that is completely silent during the drain step has either lost its supply or failed. Separating those needs a meter. It stays last because it is the conclusion once every mechanical cause is clear.
Check in this order, and why
- First: With the power off, look into the sump outlet — Remove anything visible and check the impeller turns freely. It comes first because it is the cheapest of the five to exclude and because everything below it is harder to read while it is unresolved.
- Second: Lift out the filter and rinse it — Clear the sump underneath with a sponge and check nothing is caught in the outlet.
- Third: Lift the air gap cover at the sink and clear it — Soil packed inside is common and easy to remove.
- Last: Was the disposer or the machine recently installed? — A machine that has never drained since installation points straight at the plug.
- Then: Is there any pump noise at the drain step? — Silence with a clear filter and hose points at the pump circuit.
Before you open anything
Safety
Switch off at the breaker before the toe panel comes off, and treat the capacitor as charged. Bail the standing water out before working in the base, because mains connections sit behind the panel a short distance from it. Keep hands clear of the impeller until the power is proven off.
Models in the GDBE family
Reference| Model number | Family key |
|---|---|
| GDBE250**** | conservator:dishwasher:gdbe |
When to call a technician
Call once the filter, the hose, the air gap and the impeller are all clear and water still stands, because what remains is the pump circuit and it needs a meter. Call a plumber instead if the sink backs up at the same time, because then the shared waste is the problem.
