The short answer
A Cove dishwasher is quiet by design, so any noise you can hear is information rather than background. On this machine the first suspects are the installation and the load: a hose or a bracket touching cabinetry, or an item fouling a spray arm. A worn pump is far down the list on a machine this quiet.
What you are actually seeing
- A rhythmic knocking that matches a spray arm turning — Means: on-page
- A hum or buzz that seems to come from the cabinetry rather than the machine — Means: on-page
- A rattle that changes when the racks are reloaded — Means: on-page
- A grinding from the base of the machine — Means: on-page
- A noise that only appears at one point in the cycle — Means: on-page
- A bang in the pipes when the machine fills — Means: different-fault — Go to: cove-dishwasher-water-leak
- A buzzing with no cycle running — Means: different-fault — Go to: cove-dishwasher-electrical-safety
- Body: Match what you see before you take anything apart. A rhythmic knocking that matches a spray arm turning. A hum or buzz that seems to come from the cabinetry rather than the machine. A rattle that changes when the racks are reloaded. A grinding from the base of the machine. A noise that only appears at one point in the cycle. Some near-miss symptoms belong on a different page: A bang in the pipes when the machine fills points at water hammer in the house plumbing rather than the appliance, covered on cove-dishwasher-water-leak; A buzzing with no cycle running points at an electrical fault, covered on cove-dishwasher-electrical-safety.
Causes, ranked for this machine
- An item in the rack fouling a spray arm as it turns — Why this rank: First because it produces the most obvious noise from the most trivial cause, and on a quiet machine it stands out immediately
- A hose, a bracket or a cable touching the cabinetry and transmitting vibration — Why this rank: On an integrated machine the cabinetry is a sounding board, and a hose resting against a cabinet wall makes a quiet machine audible
- Light items or cutlery moving under the spray — Why this rank: Free to fix by reloading, and it explains a rattle that changes from load to load
- A hard object that has reached the sump, such as a stone or a piece of glass — Why this rank: A grinding from the base is this until proven otherwise, and leaving it there damages the pump
- A worn wash pump or spray arm bearing — Why this rank: Last because it needs a part and because on a machine this quiet the four causes above account for most reports
- Body: Ranked for a premium built-in dishwasher: hard-plumbed, on a dedicated supply, installed under a worktop by a fitter, quiet by design, with hand-cleaned filtration and a condensation dry that depends on rinse aid. Most likely: An item in the rack fouling a spray arm as it turns. First because it produces the most obvious noise from the most trivial cause, and on a quiet machine it stands out immediately. Next most likely: A hose, a bracket or a cable touching the cabinetry and transmitting vibration. On an integrated machine the cabinetry is a sounding board, and a hose resting against a cabinet wall makes a quiet machine audible. Third: Light items or cutlery moving under the spray. Free to fix by reloading, and it explains a rattle that changes from load to load. Fourth: A hard object that has reached the sump, such as a stone or a piece of glass. A grinding from the base is this until proven otherwise, and leaving it there damages the pump. Fifth: A worn wash pump or spray arm bearing. Last because it needs a part and because on a machine this quiet the four causes above account for most reports.
What to check, in order
- Run a cycle with the machine empty to separate the load from the machine
- Spin both arms by hand with the racks loaded and check for contact
- Open the adjacent cabinet and check whether a hose or a cable is touching a cabinet wall
- Switch off at the breaker and check the sump for a hard object
- Body: Each check rules out the causes above it. First, run a cycle with the machine empty to separate the load from the machine. Second, spin both arms by hand with the racks loaded and check for contact. Third, open the adjacent cabinet and check whether a hose or a cable is touching a cabinet wall. Fourth, switch off at the breaker and check the sump for a hard object.
Checks you can safely make yourself
- Run a short cycle with the machine completely empty and note whether the noise persists — Tools: none — Time estimate: one short cycle
- Spin the upper and lower spray arms by hand with the racks loaded, checking neither touches an item as it turns — Tools: none — Time estimate: a few minutes
- Open the adjacent cabinet and gently move any hose or cable away from contact with the cabinet wall — Tools: torch — Time estimate: a quarter of an hour
- Switch off at the breaker, remove the filtration and look into the sump with a torch for glass, stones or bone — Tools: torch, gloves — Time estimate: a quarter of an hour
- Note the exact point in the cycle at which the noise occurs, since a quiet machine makes that easy to identify — Tools: notepad — Time estimate: one cycle
- Body: Checks an owner can make with the machine switched off at the breaker, or by watching a cycle. Step one: Run a short cycle with the machine completely empty and note whether the noise persists. Tools: none. Time: one short cycle. Step two: Spin the upper and lower spray arms by hand with the racks loaded, checking neither touches an item as it turns. Tools: none. Time: a few minutes. Step three: Open the adjacent cabinet and gently move any hose or cable away from contact with the cabinet wall. Tools: torch. Time: a quarter of an hour. Step four: Switch off at the breaker, remove the filtration and look into the sump with a torch for glass, stones or bone. Tools: torch, gloves. Time: a quarter of an hour. Step five: Note the exact point in the cycle at which the noise occurs, since a quiet machine makes that easy to identify. Tools: notepad. Time: one cycle.
Safety first
Safety
Switch off at the breaker and at the isolating switch before reaching into the sump, and wear gloves: a hard object under fine filtration is usually broken glass. Do not run the machine with a known object in the sump, and do not pull an integrated machine out of its opening to chase a noise: the custom panel and the worktop make that a service job. 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 a technician when an empty cycle produces the same noise, the sump is clear, the arms turn freely and nothing is touching the cabinetry. On a machine designed to be quiet, a persistent mechanical noise is a genuine signal and worth investigating properly rather than living with.
Nearest pages of the same kind
Generalized information
This page is generalized across the Cove dishwasher line. Fully integrated machines carrying a custom cabinet panel and machines with a finished front share the ranking above but not every part, and this page does not cover a specific model, control revision or installation. Family- and model-specific pages, where they exist, are linked below.
Links: - [Common COVE Dishwasher Problems](/blog/cove-dishwasher-problems) - [COVE Dishwasher: Does Not Clean or Dry](/blog/cove-dishwasher-cleaning-performance) - [COVE Dishwasher: Controls, Display or Error Code](/blog/cove-dishwasher-control-fault) - [COVE Dishwasher: Cycle Will Not Run or Complete](/blog/cove-dishwasher-cycle-fault)
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
