Quick answer
Turn off the dishwasher and unplug it. Check for trapped items in the drain pump or filter. If the buzzing continues, the motor or control board may need replacement.
Confirm the symptom
- Buzzing noise during or after the cycle
- Noise originates from the bottom of the unit
- Noise persists even when dishwasher is empty
Tools and prep
- Screwdriver set
- Flashlight
- Rubber gloves
- Plastic putty knife
- LG dishwasher manual
- Turn off power at circuit breaker
- Turn off water supply
Step-by-step troubleshooting
- Unplug and InspectDo: Unplug the dishwasher and remove the lower rack. Use a flashlight to check for trapped objects in the filter area.Observe: Look for foreign objects or debris blocking the drain pump.Means: Trapped items can cause buzzing by interfering with the pump.Next: If found, remove the object and proceed to Test Operation.
- Test OperationDo: Plug in the dishwasher and run a short cycle to see if the buzzing returns.Observe: Listen for the buzzing noise during the cycle.Means: If the noise stops, the issue was likely a temporary blockage.Next: If buzzing continues, proceed to Check Drain Pump.
- Check Drain PumpDo: Locate the drain pump (usually at the bottom rear of the dishwasher). Use a screwdriver to access and inspect for damage or blockage.Observe: Look for cracks, debris, or worn components in the pump.Means: A faulty or clogged drain pump often causes buzzing noises.Next: If damaged, proceed to Replace Drain Pump.
- Replace Drain PumpDo: Purchase a compatible drain pump and follow the manual’s instructions to install it.Observe: The buzzing should stop after replacement.Means: A damaged drain pump is a common cause of buzzing.Next: If buzzing continues, proceed to Check Motor.
- Check MotorDo: Inspect the motor for signs of wear or damage. Use a multimeter to test for continuity.Observe: If the motor is faulty, it will show no continuity or irregular readings.Means: A failing motor can produce buzzing sounds during operation.Next: If faulty, proceed to Replace Motor.
- Replace MotorDo: Purchase a replacement motor and follow the manual’s instructions for installation.Observe: The buzzing should cease after replacing the motor.Means: A defective motor is a common source of buzzing in dishwashers.Next: If buzzing persists, contact a professional technician.
Common causes
| Cause | Likelihood | Difficulty | Part often needed |
|---|---|---|---|
| Trapped Objects in Drain Pump Foreign objects can block the pump, causing it to buzz. | Common | Easy | Drain Pump |
| Clogged Filter A dirty filter restricts water flow and may cause buzzing. | Common | Easy | Filter |
| Faulty Drain Pump A damaged or worn pump can vibrate and create buzzing sounds. | Sometimes | Medium | Drain Pump |
| Failing Motor A motor with worn components can produce buzzing noises. | Sometimes | Hard | Motor |
| Loose Components Loose parts can vibrate and create buzzing during operation. | Rare | Easy | Screws/Washers |
| Faulty Control Board A malfunctioning control board may send irregular signals to components, causing buzzing. | Rare | Hard | Control Board |
Parts matching
Common parts needed for an LG dishwasher buzzing issue:
- Drain Pump
- Filter Assembly
- Motor
- Control Board
- Screws and Washers
Always refer to your LG dishwasher model number when purchasing replacement parts to ensure compatibility.
When to call a professional
- Buzzing persists after replacing the drain pump and filter
- You detect unusual smells or water leaks
- You're unsure about electrical components like the motor or control board
- The dishwasher doesn't start or fill with water after repairs
- You hear loud grinding or knocking noises in addition to buzzing
FAQ
Can I clean the drain pump myself?
Yes, you can clean the drain pump by unplugging the dishwasher, removing the lower rack, and using a flashlight to check for debris. Clear any blockages with a plastic putty knife.
How do I know if the motor is faulty?
If the dishwasher doesn’t spin or you hear a buzzing noise without the pump/motor turning, the motor may be faulty. Use a multimeter to test for continuity.
Is a buzzing noise always a serious problem?
Not always. A buzzing noise can be caused by a simple blockage or loose part. However, if it persists after cleaning and inspection, it may indicate a more serious issue like a faulty motor or control board.
Can a clogged filter cause buzzing?
Yes, a clogged filter can restrict water flow and cause the pump to work harder, resulting in a buzzing noise. Regularly cleaning the filter can prevent this issue.