Bosch Dishwasher: intermittent loud noise

Professional Repair Guide

What is this symptom?

Is your Bosch dishwasher producing intermittent loud noises during operation? These sounds, which can include grinding, buzzing, or rattling, often occur during wash or drain cycles. This issue may be caused by foreign objects, improper loading, or worn parts. Understanding these causes can help you address the problem effectively.

Urgency: Medium

Important Tips for Bosch Models

  • Bosch manuals note that loud grinding or buzzing noise is often due to pump impeller blockage and instruct to check the pump area.

Possible Causes

Foreign objects or debris in pump/impeller area

How to Identify: Loud grinding or buzzing during drain or wash cycle; debris visible when filter and pump cover removed

Part: Drain pump impeller / circulation pump impeller

Improper loading causing spray arm obstruction

How to Identify: Rattling or knocking noise coincides with spray arm rotation; noise stops when load rearranged

Part: Spray arms and utensils

Worn pump motor bearings or worn impeller blades

How to Identify: Persistent grinding or humming noise even without debris; noise loud and mechanical in character

Part: Circulation pump motor bearings; wash impeller

Loose internal parts or screws causing vibration

How to Identify: Rattling sound not tied to specific cycle; noise decreases after tightening components

Part: Internal fasteners, panels

Drain hose or drainage path obstruction

How to Identify: Gurgling or humming during drain leads into louder noise; potential water not draining fully

Part: Drain hose and filter area

DIY Solutions

Clean pump area and remove debris

Moderate 15-30 minutes
Tools Needed: screwdriver (if needed), gloves, towels/sponge
  1. Turn off power and open dishwasher
  2. Remove lower rack and filter unit
  3. Remove pump cover and inspect impeller area for debris
  4. Remove any visible foreign objects
  5. Re-install pump cover, filter, and rack; test run
⚠️ Safety First: Disconnect power before reaching into pump area

Rearrange and load dishes properly

Easy 5-10 minutes
  1. Open dishwasher mid-cycle if safe
  2. Rearrange dishes ensuring spray arms have clearance
  3. Avoid nesting utensils and secure lightweight items
  4. Run cycle to check if noise persists
⚠️ Safety First: Ensure cycle is paused and water jets are off before reloading

Tighten loose screws and panels

Easy 10 minutes
Tools Needed: screwdriver
  1. Ensure dishwasher is off
  2. Check underside panel, interior screws for looseness
  3. Tighten any loose fasteners
  4. Run a test cycle to check noise reduction
⚠️ Safety First: Avoid overtightening which might strip screws

Professional Repairs

Replace drain or circulation pump impeller or assembly

Estimated Cost: $80 - $300

Replace worn motor bearings or wash impeller

Estimated Cost: $150 - $400

Inspect and service drain hose/valve if clogged or damaged

Estimated Cost: $100 - $250

When to Call a Professional

Loud grinding persists after debris removal
Noise comes from pump motor bearings (mechanical hum/grind)
Drain noise with poor draining or error codes

Preventive Maintenance

  • Clean filter and pump area: Debris buildup causing noise and clogging
    Frequency: monthly
  • Check and clean spray arms: Spray arm obstruction and noise
    Frequency: monthly
  • Ensure proper loading: Spray arm collision and related noise
    Frequency: Every use

Frequently Asked Questions

Why is my Bosch Dishwasher intermittent loud noise?
Common causes include foreign objects in the pump, improper dish loading, worn motor bearings, or loose internal parts.
How do I fix Bosch Dishwasher intermittent loud noise myself?
You can clean the pump area, rearrange dishes for proper loading, or tighten any loose screws or panels.
How much does it cost to fix intermittent loud noise?
Professional repairs can range from $80 to $400 depending on the specific issue, such as replacing the pump or motor.
When should I call a technician for intermittent loud noise?
If DIY solutions don't resolve the issue or if the noise persists, it's advisable to consult a professional for a thorough inspection.

References & Sources

Community Analytical Insights

Analysis based on real user discussions from appliance repair communities

Can I Fix This Myself?

75%
DIY Success Rate Difficulty: Either

Common Issues Reported by Users

  • Worn or damaged wash impeller
  • Debris or foreign objects in the spray arm
  • Faulty drain pump

User Suggested Solutions

  1. Inspect and clean the spray arm. Remove any debris or foreign objects that may be obstructing the spray arm's movement. Ensure it spins freely.

  2. Check the wash impeller for wear or damage. If it's worn out, replace it. Ensure all components are securely attached.

  3. Test the drain pump for proper operation. If it's making unusual noises or not functioning correctly, replace it.

Analysis based on 1 community discussions
View Sources

Data compiled from real discussions on r/appliancerepair and r/Appliances:

  1. Help needed with noise reduction on Bosch dishwasher

Community Discussions

loud noise during wash cycle

Replace the drain pump and clean out other parts in the system.

DIY View on Reddit →

Source: Reddit r/appliancerepair

User Comments (0)

Share your experience or solution below.

Be the first to comment!