The short answer
On an AEG Electrolux dishwasher, a smell or mould in the machine most often comes back to a drain hose whose inner wall has roughened with age, with biofilm on the filter and in the sump close behind. Age, not electronics, sets the ranking here: hardened door seals, worn pump impellers, scaled heating elements and a chafed door harness fail long before the board does, and they fail in the order wear predicts. That puts the first move in your hands rather than a technician’s: work the checks below in order and stop at the first one that explains what you are seeing.
What you are seeing
- What this fault looks like, and which observations point somewhere else.
- slime in the corners of the door seal
- a stale or drain-like smell when the door is opened
- a dark film on the filter, the sump edge or the underside of the door lip
- the smell strongest after the machine has stood unused for a day
- Not this fault: if the smell is of hot plastic rather than stale water, read the electrical-safety page
Ranked causes on this platform
- Ranked for an AEG Electrolux dishwasher, which runs an earlier-generation controller whose indicator sequence, not a numeric display, reports the fault on many models. No measured frequency exists for this address, so the order is platform judgement rather than a share.
- A drain hose whose inner wall has roughened with age — Why: On a machine of this age the hose itself holds the smell, and cleaning the tub above it changes nothing.
- Biofilm on the filter and in the sump — Why: This is where the smell lives on almost every machine, and it is owner maintenance rather than a repair.
- Standing water in the drain hose — Why: Without a high loop the hose holds dirty water permanently, and the smell returns however well the tub is cleaned.
- The door seal and the lip beneath the door — Why: The lip below the door line never gets washed by the machine, so it holds soil that nothing in a normal cycle reaches.
- Soil trapped in the spray arms — Why: Arms that are never removed collect debris inside, and it decays where no cycle washes it.
What to check, in order
- The order follows the ranking above: most likely and cheapest first, nothing needing a meter until everything else is eliminated.
- A drain hose whose inner wall has roughened with age — Because: on a machine of this age the hose itself holds the smell, and cleaning the tub above it changes nothing.
- Biofilm on the filter and in the sump — Because: this is where the smell lives on almost every machine, and it is owner maintenance rather than a repair.
- Standing water in the drain hose — Because: without a high loop the hose holds dirty water permanently, and the smell returns however well the tub is cleaned.
Checks you can safely do yourself
- Isolate the appliance before any panel comes off, and stop at the first step that explains the fault.
- Smell the hose at the connection with the machine isolated, and compare it with the tub. — Tools: a torch — Time estimate: a quarter of an hour
- Remove and scrub the filter stack, then wipe the sump and the impeller cover. — Tools: a brush and warm soapy water — Time estimate: a quarter of an hour
- Check the hose rises to a high point before falling to the waste connection. — Tools: a torch — Time estimate: a quarter of an hour
- Wipe under the door lip and into the seal corners with a cloth and see what comes off. — Tools: a cloth — Time estimate: a quarter of an hour
- Stop condition: Stop there: the next step means metering live terminals or opening a sealed system.
Safety first
Safety
Unplug the appliance or switch off its breaker before removing any panel, because a capacitor can hold a charge after the power is off. Isolate the circuit before reaching into the sump, and treat the water in a machine that has just run as hot enough to scald. Never defeat the door latch to run the machine open; the latch switch exists to stop the wash the moment the door moves.
When to call a technician
Call a technician when the smell survives a full clean of the filter, the seal and the arms, when dirty water returns to the tub between cycles, or when the drain hose has to be replaced behind the machine. A persistent drain smell with back-flow is a plumbing job rather than a cleaning one.
The fact bundle for this address was empty, so no warehouse figure appears. Every number on the page is a program safety constant, cited to its publisher. — Sources
General guidance- 1910.147 — The control of hazardous energy (lockout/tagout) — Occupational Safety and Health Administration, fetched 2026-09-06
Other faults documented for this brand and appliance. — Nearest pages of the same kind
What this page does not cover
This page is generalized across every AEG Electrolux dishwasher family and model number: no family fault list, no model parts list, and no measured figure from the program warehouse. Where a family- or model-specific page exists it goes deeper, and it should be preferred over this one.
Links: - [Common AEG Electrolux Dishwasher Problems](/blog/aeg-electrolux-dishwasher-problems) - [AEG Electrolux Dishwasher: Abnormal Noise or Vibration](/blog/aeg-electrolux-dishwasher-abnormal-noise) - [AEG Electrolux Dishwasher: Does Not Clean or Dry](/blog/aeg-electrolux-dishwasher-cleaning-performance)
Adjacent pages for what this one rules out. — Where to go next
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
