Dishwashers are designed to run smoothly and quietly in the background, taking care of one of the most time-consuming chores in any home. So, when your dishwasher suddenly starts making loud, unusual noises during operation, it can be alarming—and disruptive. While some occasional sounds might be harmless, persistent or new noises could be signs of deeper mechanical issues. The two most common causes? A worn-out pump or a foreign object stuck inside.
Let’s break down how to recognize the problem, what might be causing it, and why prompt attention is important.
Common Dishwasher Noises and What They Mean
Before jumping to conclusions, it helps to understand what type of noise your dishwasher is making. Each sound can indicate a different kind of malfunction:- Grinding – Often caused by something hard, like a piece of broken glass or a seed, caught in the chopper blade or circulation pump.
- Buzzing or Humming – A light humming is normal, but if it’s unusually loud, it could be the motor straining due to a blockage or a worn-out bearing.
- Squealing or High-Pitched Whining – This may indicate that the pump motor is wearing down or that the internal seals are failing.
- Banging or Thudding – This is usually caused by items inside the dishwasher moving or hitting each other. However, it can also result from a loose spray arm or hose.
Worn-Out Pump: What to Look For
The pump is responsible for circulating and draining water during the wash cycle. It has moving parts, including impellers and seals, which can degrade over time. Signs your pump may be failing:- Loud grinding or whining noise coming from the bottom of the machine
- Dishes not being cleaned properly
- Water remaining at the bottom after the cycle
- Burning smell or overheating
Foreign Object Inside: A Common and Avoidable Issue
It’s easy to miss small objects when loading the dishwasher—think popcorn kernels, bones, broken glass, or even labels from jars. These can get lodged in various parts of the system and create abnormal noises during operation. Possible trouble spots:- Filter: Small debris often gets trapped here, especially if the filter hasn’t been cleaned in a while.
- Spray Arms: Items can block or damage the spray arms, making them hit dishes or rotate improperly.
- Drain Pump: Foreign materials can damage or clog the drain pump, leading to strain and noise.
- Chopper Blade: This part grinds up food particles. If something hard enters it, the blade can get damaged or make a rattling sound.
When Should You Call a Technician?
Some minor issues, like a utensil out of place or a clogged filter, can be fixed at home. However, ongoing loud noises, especially grinding, whining, or humming, point to something more serious. Call a repair service if you notice:- Persistent loud noises with every cycle
- Unusual smells or water leaks
- Poor cleaning performance
- Standing water inside after completion