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ErrBase

Bosch Dishwasher Making Noise: Pump, Spray Arm, and Motor Diagnosis

Quick Answer

Bosch dishwashers are engineered to run at 44 dB - whisper-quiet. Any new noise has a specific source. Grinding during wash = food debris in the wash pump impeller. Knocking = spray arm hitting a protruding dish. Humming during drain = normal drain pump. Buzzing = water inlet valve activating. Sudden loudness after years of quiet = wash motor bearings starting to wear.

Bosch dishwashers are engineered for quietness (44 dB on 800 Series is whisper-quiet). Any noise stands out. Grinding during wash = food debris in the wash pump. The fine mesh filter on Bosch models catches smaller particles than many brands but lets some through to the pump. Humming during drain = normal drain pump. Buzzing = water inlet valve. Knocking = spray arm hitting a protruding dish or utensil. A rattling noise from underneath = the drain pump check valve flapping (normal on some models). If the Bosch is suddenly louder than when new, the wash motor bearings may be wearing - this is rare before 10 years on Bosch but does happen. Bosch motors use ceramic bearings on premium models that last longer than steel bearings.

BoschDishwasherSeverity: mediumDifficulty: intermediate75% DIY Success
Time to Fix
15–90 min
Difficulty
intermediate
Parts Cost
—
Tools Needed
Multimeter, Screwdriver

What Does the NOISE Code Mean?

Bosch dishwasher noise: designed for 44 dB (800 Series).

Most Likely Causes

Based on aggregated repair data, here is the probability breakdown for this error code:

Food debris in wash pump impeller (grinding)35%
Spray arm hitting a dish or utensil (knocking)30%
Inlet valve buzzing (buzzing on fill)15%
Drain pump check valve (normal rattling)12%
Worn motor bearings (low rumble)8%

Symptoms You May Notice

  • Bosch dishwasher noise

Can you reset a Bosch dishwasher to clear the NOISE code?

Unplug 60 seconds.

Tools Required for Diagnosis

MultimeterScrewdriverFlashlight

Diagnostic Checklist

Follow these steps in order. We start with the easiest external fixes before opening up the machine.

1

Follow brand-specific diagnosis in guide above.

Follow brand-specific diagnosis in guide above.

2

Check error codes.

3

Professional if needed.

Frequently Asked Questions

Repair cost?
$100-400 typical.
DIY?
Many fixes DIY. Gas/sealed need pros.
Worth it?
Under 10 years = usually yes.

Same Fix Works on These Brands

Bosch shares the same hardware platform with these brands. The diagnosis and repair steps are identical.

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Last verified for technical accuracy on March 15, 2026