Asko Washer: Odor or Mold
A washer that smells is growing biofilm in the places that stay wet between washes — the door boot, the detergent drawer and the drain hose — and the smell is a maintenance problem rather than a fault. This page takes the same fault from a different starting point: not which subsystem is likeliest on an Asko washer, but when the trouble started. These are heavily built machines, so wear-out ranks low and installation, water-path obstructions and load habits rank high. What ranks first here is something you can correct yourself in under an hour, which is the reason to work down the list in order rather than book a visit straight away.
What you are actually seeing
- Check your symptom against this list first.
- The smell is strongest after the machine has been closed up for a day.
- A slimy film inside the detergent drawer housing.
- Black or grey marks in the fold of the door boot.
- Laundry that smells damp within hours of coming out.
- Not this fault: If the smell is sewage rather than musty, the drain connection or the standpipe trap is the more likely source.
Causes, grouped by when it started
- One entry per onset pattern first — the strongest candidate for each way this fault can begin on an Asko washer — and the remainder after them. Read the label, find the pattern that matches yours, and start there rather than at the top.
- Drain hose without a trap, letting drain odours back in — Why: A drain connection with no air gap or trap lets the household drain smell come back up into the machine, which is a plumbing fault rather than an appliance one. This ranks above component wear on a machine of this build quality: the parts are heavy-duty, the installation is whatever the room allowed. — Onset: Has been like this since the unit was installed or moved
- Biofilm in the door boot and the drum — Why: The fold of the boot holds water, lint and detergent residue after every wash, and that is exactly the environment mould needs. It is the first place to look and the easiest to correct. — Onset: Got worse gradually over weeks or months
- Washing cold, and the door kept closed between loads — Why: Low temperatures do not clear residue, and a sealed drum stays damp for days. Together they are the two habits that produce almost every smelling washer. — Onset: Happens on some cycles or some days and not others
- Detergent drawer and its housing never cleaned — Why: The housing behind the drawer is out of sight and rarely washed, and it develops a thick residue that smells whenever water passes through it. — Onset: Got worse gradually over weeks or months
What to check, and in what order
- This order follows the onset groups above, so it is deliberately different from the companion page. Neither is wrong; they are two routes through one fault.
- Pin down when it started and whether it happens every time. — Why: A fault that appeared between one use and the next has a different cause set from one that crept up over months, and this answer alone removes most of the list.
- Pull the door boot fold open all the way round and look at what is in it. — Why: It is the most common source and it is visible without any tools.
- Remove the detergent drawer and look at the housing behind it. — Why: Second most common, equally visible, and takes two minutes.
Checks you can safely do yourself
- Stop at the first step that would put a meter on live terminals.
- Pull the door boot fold open all the way round, remove debris, and clean it with a mould-safe cleaner and a cloth. — Tools: Cloth, mould-safe cleaner, gloves
About 25 min
- Remove the detergent drawer, wash it and scrub the housing behind it with warm water and a brush. — Tools: Brush, warm water
About 20 min
- Switch the machine off, open the pump filter over a tray, clean it and refit it fully. — Tools: Towels, tray
About 25 min
- Run the drum-clean cycle, or the hottest cycle with an empty drum and a proper machine cleaner. — Tools: Machine cleaner — Time: 1–2 hours
Before you touch anything
Safety
Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off. — Id: unplug-before-service
Unplug the washer before opening the pump filter or any panel; a capacitor in the drive circuit holds a charge after the power is off. Never mix cleaning products, and in particular never mix bleach with any other cleaner — the gas that produces is dangerous in a small laundry room. Wear gloves and ventilate the room while cleaning mould.
Where the owner checks end
Call a technician when one of these is true, and not before.
When the smell persists after the boot, drawer, filter and a hot clean cycle have all been done. When the boot is torn or the mould has penetrated the rubber and cannot be cleaned out. When the smell is of drains rather than mould, which points at the drain connection.
Sources
General guidance- 29 CFR 1910.147 — The Control of Hazardous Energy — US Occupational Safety and Health Administration, fetched 2026-09-06
Nearest pages of the same kind
What this page does not cover
Links down: - [Common Asko Washer Problems](/blog/asko-washer-problems-2)
This page is generalized: it covers the Asko washer line as a whole and does not narrow to a family, a model number or a serial range. The overview at asko-washer-problems-2 routes down to every problem class on this machine, including any family- or model-specific page beneath this one.
Other faults on this machine
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
