The short answer
A AIRMSEN dishwasher that smells is holding food debris somewhere that never dries. On a compact or countertop machine with a small sump, a single pump and a short hose run, which fails differently from a built-in, the filter and sump come first, the drain path second, and the door gasket third — and all three are owner-cleanable.
What you are actually seeing
- A musty smell when the door is opened — Residue inside: filter, sump and the area under the lower spray arm.
- A drain or sewage smell — The waste connection, the trap or the disposer rather than the machine.
- Dishes come out smelling of the machine — The film is being recirculated, which means the filter and sump need attention now.
- Standing water with a smell — A drainage fault: the water should not be sitting there, and that page is where to start.
- The smell is strongest after the machine has been idle — Classic biofilm behaviour in a closed damp box.
- Not this fault: a burning or hot-plastic smell — Stop using the machine. That is electrical and it belongs on the electrical safety page.
Causes, most likely first on this machine
- Food debris in the filter and sump — First and commonest: the filter is doing its job and nobody has emptied it.
- A film in the drain hose or the waste connection — Second: water stands there between cycles, and the smell it produces is sharper and more drain-like.
- Grease and residue under the spray arms and around the door — Third: the places a rinse never reaches properly, including the gasket fold.
- Running only short, cool cycles — Fourth: they do not shift grease, so residue accumulates faster than it is removed.
- A dirty food waste disposer, where one is fitted — Fifth: the machine gets the blame for a smell it merely shares.
- Standing water from a drainage fault — Last in this ranking but first to fix if present: a sump that never empties cannot be kept clean.
Check in this order, and why
- Open the door and identify the smell — Musty means inside the machine; drain-like means the waste path. They lead to different work.
- Check for standing water — If there is any, the drainage fault comes first and the smell follows it.
- Remove and clean the filter and sump — The single most effective action, and the one most machines have never had.
- Clean the spray arms and the door gasket — The places grease survives a normal cycle.
- Then run a hot cleaning cycle — Last, because it works on a machine that has already been cleaned by hand.
What an owner can safely check
- Remove and wash the filter and clear the sump — Breaker off, gloves on, and look for glass. Warm soapy water and a brush, and check under the filter seat.
Tools: brush, glovesAbout 25 min
- Clean the spray arms and their bearings — Take them off, rinse the holes clear, and wipe the spindle they turn on where grease collects.
Tools: pin, clothAbout 25 min
- Wipe the door gasket and the door edge — Right round the fold, including the bottom edge below the door where debris collects out of sight.
Tools: cloth, white vinegarAbout 20 min
- Run the hottest cycle empty with a machine cleaner — No dishes. Repeat after a week if the smell was strong, and clean the filter again afterwards.
About 90 min
- Change what caused it — Run a hot cycle regularly rather than only eco ones, scrape plates before loading, and leave the door ajar between washes.
About 5 min
Before you open anything
Safety
Unplug the appliance or switch off its breaker before reaching into the sump — a capacitor can hold a charge after the power is off, and broken glass is common down there. Never mix cleaning products: bleach and an acidic cleaner together produce a harmful gas. Do not pour drain chemicals into the machine; they damage seals and remain where your hands go next. Keep machine cleaners away from children, and let the tub cool before working in it.
When to call a technician
Call when a thorough clean of the filter, sump, arms and gasket plus a hot cleaning cycle leaves the smell in place, because that points at the drain hose or residue somewhere an owner cannot reach. Call sooner if the smell is sewage rather than mould, which usually means the waste connection or the trap, and if there is standing water in the sump — the drainage fault behind it is what actually needs fixing.
Sources
Documented- 29 CFR 1910.147 — The control of hazardous energy (lockout/tagout) — osha.gov, fetched 2026-09-12
- U.S. Consumer Product Safety Commission — product safety and recall notices — cpsc.gov, fetched 2026-09-12
Nearest pages of this class
What this page does not cover
This page covers the appliance class under this nameplate rather than one family or model. Filter shapes, spray-arm mountings, cleaning-cycle names and part numbers differ by platform and belong on the model-specific page linked below where one exists. Waste plumbing and disposer maintenance are outside its scope.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
