The short answer
A smell from a Costway portable washer is almost always water left standing in the tub, the filter or the hoses between uses. These machines are used, drained by hand and then stored, which leaves them wet and closed for days. Emptying and drying them properly is the whole fix.
What you are actually seeing
- A sour or musty smell from the tub — Means: on-page
- A smell that is worst after the machine has been stored — Means: on-page
- Visible film in the tub or around the lint filter — Means: on-page
- Laundry that comes out smelling worse than it went in — Means: on-page
- A drain smell from the hose rather than the tub — Means: on-page
- A burning or hot plastic smell — Means: different-fault — Go to: costway-washer-electrical-safety
- A smell with water still standing in the tub — Means: different-fault — Go to: costway-washer-drainage-failure
- Body: Match what you see before you take anything apart. A sour or musty smell from the tub. A smell that is worst after the machine has been stored. Visible film in the tub or around the lint filter. Laundry that comes out smelling worse than it went in. A drain smell from the hose rather than the tub. Some near-miss symptoms belong on a different page: A burning or hot plastic smell points at an electrical fault to stop using the machine over, covered on costway-washer-electrical-safety; A smell with water still standing in the tub points at a drain fault feeding the smell, covered on costway-washer-drainage-failure.
Causes, ranked for this machine
- Water left standing in the tub or the base after use — Why this rank: First because these machines are drained by hand and stored closed, so a residue is normal unless the owner clears it
- A lint or pump filter holding stale water and debris — Why this rank: Small filters fill quickly and are rarely opened
- A drain hose coiled and stored with water inside it — Why this rank: The hose is stored rather than plumbed, so it keeps its own puddle
- Detergent residue and over-dosing feeding biofilm — Why this rank: Over-dosing is common on a small tub because the tub looks small but the water is smaller still
- A lid kept closed on a wet tub in a warm room — Why this rank: Last, but it is the habit that makes every cause above worse
- Body: Ranked for a portable washer: either a twin-tub with a separate wash tub and spin basket that drains by gravity, or a compact single-tub machine that fills from a tap adapter and drains with a pump. Most likely: Water left standing in the tub or the base after use. First because these machines are drained by hand and stored closed, so a residue is normal unless the owner clears it. Next most likely: A lint or pump filter holding stale water and debris. Small filters fill quickly and are rarely opened. Third: A drain hose coiled and stored with water inside it. The hose is stored rather than plumbed, so it keeps its own puddle. Fourth: Detergent residue and over-dosing feeding biofilm. Over-dosing is common on a small tub because the tub looks small but the water is smaller still. Fifth: A lid kept closed on a wet tub in a warm room. Last, but it is the habit that makes every cause above worse.
What to check, in order
- Drain the tub completely and tip out any residue
- Empty and rinse the lint or pump filter
- Empty the drain hose and store it hanging rather than coiled
- Leave the lid open between uses and dry the tub
- Body: Each check rules out the causes above it. First, drain the tub completely and tip out any residue. Second, empty and rinse the lint or pump filter. Third, empty the drain hose and store it hanging rather than coiled. Fourth, leave the lid open between uses and dry the tub.
Checks you can safely make yourself
- Drain the tub fully, then tip or sponge out the last of the water and wipe the tub dry — Tools: sponge, cloth — Time estimate: a quarter of an hour
- Unplug the machine, open the lint or pump filter over a tray, empty it, rinse it and refit it — Tools: tray, towel — Time estimate: a quarter of an hour
- Hold the drain hose low so it empties completely, then store it hanging rather than coiled — Tools: none — Time estimate: a few minutes
- Run a hot empty cycle with a small dose of washing machine cleaner and then drain and dry the tub — Tools: washer cleaner — Time estimate: one cycle
- Leave the lid open between uses for a fortnight and judge whether the smell returns — Tools: none — Time estimate: a fortnight of habit
- Body: Checks an owner can make with the machine unplugged or by watching a short cycle. Step one: Drain the tub fully, then tip or sponge out the last of the water and wipe the tub dry. Tools: sponge, cloth. Time: a quarter of an hour. Step two: Unplug the machine, open the lint or pump filter over a tray, empty it, rinse it and refit it. Tools: tray, towel. Time: a quarter of an hour. Step three: Hold the drain hose low so it empties completely, then store it hanging rather than coiled. Tools: none. Time: a few minutes. Step four: Run a hot empty cycle with a small dose of washing machine cleaner and then drain and dry the tub. Tools: washer cleaner. Time: one cycle. Step five: Leave the lid open between uses for a fortnight and judge whether the smell returns. Tools: none. Time: a fortnight of habit.
Safety first
Safety
Unplug the machine before opening a filter housing or reaching into the tub, and keep the room ventilated while using a cleaner. Never mix a chlorine product with another cleaning product in the tub. Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off. unplug-before-service
Where the owner fix ends
Call for a warranty claim or a technician when the tub is drained and dried, the filter is clean, the hose is emptied, a cleaner cycle has run and the lid is left open, and the smell still returns within days. That points at a hose interior or a sump beyond an owner clean.
Nearest pages of the same kind
Generalized information
This page is generalized across the Costway portable washer line. Twin-tub machines and compact single-tub machines share the ranking above but almost none of their parts, and this page does not cover a specific model or control revision. Family- and model-specific pages, where they exist, are linked below.
Links: - [Common COSTWAY Washer Problems](/blog/costway-washer-problems) - [COSTWAY Washer: Abnormal Noise or Vibration](/blog/costway-washer-abnormal-noise) - [COSTWAY Washer: Does Not Clean or Dry](/blog/costway-washer-cleaning-performance) - [COSTWAY Washer: Controls, Display or Error Code](/blog/costway-washer-control-fault)
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
