Dishwasher making a noise: causes and safe checks

Usually simple

Quick answer

Humming as it fills, spraying sounds, a pump hum while draining and clicks from the detergent dispenser are normal. Rattling or knocking usually means dishes touching or a spray arm hitting something. Grinding often means glass or debris in the filter or pump area. Check the loading, spray arms, filters and levelling.

Also covers: dishwasher grinding noise · dishwasher knocking · dishwasher loud.

This can be normal

AEG lists humming when filling, spraying sounds, the drain pump humming near the end, and clicks from the detergent dispenser as normal operation.

Likely causes

What you can safely check yourself

Stop and call a qualified engineer if:
  • The code or problem comes back after you’ve done the safe checks on this page.
  • The next step would mean removing a cover or panel, or working on the pump, valves, heater, motor, door lock or wiring. That is a job for a qualified engineer.
  • You smell burning, see smoke or scorch marks, or the appliance trips your electrics. Stop using it, and switch it off at the wall only if it is safe to reach. Otherwise switch off at the consumer unit.

Work through these in order. Stop as soon as one of the signs above applies.

Check the loading

  1. Make sure nothing stops the spray arms turning or blocks the detergent compartment lid.
  2. Leave space between items so water and heat reach every surface.
  3. Put heavily soiled pans in the lower basket, and cups and glasses in the upper basket.
  4. Scrape food off plates before loading.

Check the spray arms turn and aren’t blocked

Before you start
  • Switch off and unplug the appliance at the wall socket before you touch hoses, filters or the back of the machine. Make sure your hands and the plug area are dry.
  1. With the dishwasher switched off, turn each spray arm by hand. It should spin freely without hitting plates, pans or utensils.
  2. Look at the nozzle holes. Clear food or limescale with a cocktail stick or tweezers.
  3. If your manual shows how to remove the spray arms, rinse them through under the tap and refit them firmly.

Clean the dishwasher filters

Before you start
  • Switch off and unplug the appliance at the wall socket before you touch hoses, filters or the back of the machine. Make sure your hands and the plug area are dry.
  • Wear protective gloves. Broken glass and sharp debris can collect in the filter and pump area, and it is hard to see.
Dishwasher filter assembly Twist to unlock, lift out Coarse filter Flat fine filter sits flat in the base Wear gloves: glass collects here. Refit until it locks.
Dishwasher filter assembly. Positions vary by model — check your manual.
  1. Take out the lower basket.
  2. Twist and lift the filter unit out of the base of the tub, then separate the parts as your manual shows.
  3. Rinse every part under running water. Use a soft brush for stubborn debris and nothing abrasive.
  4. Wipe food remains out of the sump area around the filter opening.
  5. Refit the filters so they lie flat and lock in position. On many models arrows line up when they are locked.

Don’t run the dishwasher without the filters fitted.

Check the dishwasher is level

  1. Put a spirit level on the open door and the front edge of the tub. Your manual shows how to adjust the feet.
  2. On integrated dishwashers, check the furniture door panel is fitted securely. AEG says built-in models must not be used without it.

Don’t pull a built-in dishwasher out of its housing to level it. Ask an installer.

Step-by-step guides

Related problems

More dishwasher problems and codes, or use the fault finder.

Sources

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We write every page in our own words from manufacturer guidance and check it against the sources above. If your manual says something different, follow your manual. How we check.