The short answer
A new noise from a AIRMSEN dishwasher is most often something in the load rather than something in the machine. On a compact or countertop machine with one spray arm, a small sump and a short hose run, a spray arm striking a tall item, and debris in the sump, explain the majority of these.
What you are actually seeing
- A rhythmic knock or clatter during the wash — A spray arm striking something in the rack. Run it empty to confirm in one cycle.
- A grinding at the start or end of the cycle — The drain pump with something in it, usually glass or a fruit stone.
- A rising whine throughout the wash — The wash motor. Normal at a low level; worth attention when it changes.
- Banging in the pipes when it fills — Water hammer in the plumbing rather than a machine fault.
- A rattle against the cabinet or worktop — Level and contact: free to fix and frequently misread as a bearing.
- Not this fault: normal pump and drain sounds at the usual level — A dishwasher is not silent, and a machine that always sounded like this is not developing a fault.
Causes, most likely first on this machine
- A spray arm striking an item in the rack — First: a tall glass, a pan handle or a board in the wrong slot, and it is confirmed or eliminated by one empty cycle.
- Debris in the sump or the drain pump — Second: glass fragments and fruit stones grind audibly and are usually removable by hand once the filter is out.
- The machine not level, or touching the cabinet — Third, and free: it turns ordinary vibration into a knock.
- A spray arm bearing worn or an arm not clipped home — Fourth: an arm that wobbles rather than spinning cleanly rattles against the rack above it.
- Water hammer in the supply — Fifth: a plumbing characteristic rather than an appliance fault, and it appears at fill and at the moment the valve closes.
- The wash or drain pump bearing — Last: a genuine mechanical failure, and much less common than the five above it.
Check in this order, and why
- Run the machine empty — It separates the load from the machine in a single cycle and usually ends the investigation.
- Check the spray arms spin freely and are clipped home — Spin each one by hand; it should turn without wobble or contact.
- Clean the filter and look in the sump — Glass and stones are visible, and removing them removes the grinding.
- Check level and clearance against the cabinet — Free, and it explains a knock that no part replacement would fix.
- Only then treat it as a pump fault — Which means the machine out and a technician, so it belongs last.
What an owner can safely check
- Run an empty cycle and listen — No dishes, no racks loaded. Note whether the noise survives and at which stage it occurs.
About 60 min
- Remove the spray arms and check them — Spin each by hand, clear the holes, and clip them back firmly. An arm not fully home rattles against the rack.
Tools: pinAbout 20 min
- Clean the filter and search the sump — Breaker off, gloves on, torch in hand. Glass fragments are the usual find and they are what grinds.
Tools: gloves, torchAbout 25 min
- Level the machine and check it does not touch the cabinet — Adjust the feet a quarter turn at a time until it is steady and nothing contacts the sides.
Tools: spirit level, adjustable spannerAbout 25 min
- Stop here if the pump must come out — That means the machine withdrawn with plumbing and power connected, which is where owner work ends.
Before you open anything
Safety
Unplug the appliance or switch off its breaker before reaching into the sump or removing any panel — a capacitor can hold a charge after the power is off, and broken glass is the usual find in a sump. Wear gloves and look before reaching. Do not open the door mid-cycle to locate a noise: the steam can scald. Do not run the machine with the kickboard removed to listen. Withdrawing a built-in machine with its plumbing connected is how floors and hoses get damaged.
When to call a technician
Call when the empty-cycle test leaves the noise unchanged and the filter, sump, arms and level are all clear, because what remains is a pump or a motor bearing inside the machine. Call sooner if the grinding is accompanied by poor drainage, which points at the drain pump specifically, and if the machine trips a protective device when the noise occurs — that combination is electrical and it should stop being used until it is checked.
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. Pump types, spray-arm mountings, rack layouts and part numbers differ by platform and belong on the model-specific page linked below where one exists. Kitchen plumbing noise and cabinetry acoustics are outside it.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
