Why Is My Dishwasher So Loud? Noises and What They Mean

What your dishwasher's noise is telling you

A dishwasher cycles through filling, washing, draining, and drying. Each stage has a different sound profile. When a new sound appears, it is usually a sign that something changed inside the machine: a part has worn, a component has worked loose, or an object has found its way into the pump. The table below compares the common noises and the components most often involved.

Before you start inspecting, note when the noise happens. A noise at the start of the cycle points to the water inlet. A noise during spray points to the recirculation pump or spray arms. A noise at the end points to the drain pump. Timing narrows down the likely cause.

Grinding noise during the wash cycle

A grinding noise is usually mechanical. It often comes from a spray arm rubbing against something or a pump impeller grinding debris. Start with the simplest check: open the dishwasher and spin each spray arm by hand. If the arm catches or rubs on a dish, the noise may be a dish that extends too far, especially in the best 24 inch built in dishwashers or best 18 inch built in dishwashers format. Reposition the dish so the arm can rotate freely.

If the spray arm spins freely by hand, the grinding may come from the circulation pump. Food debris or a small object like a toothpick or glass shard can get pulled into the pump housing and grind against the impeller. Many dishwashers have a fine mesh filter (see self cleaning filter vs manual filter). If the filter is torn or missing, debris can reach the pump. Check the filter, remove any foreign objects.

A worn pump bearing can also produce a grinding sound that worsens over time. If you cannot isolate the noise after cleaning, the pump may need service, and in many cases a new dishwasher is better value than a repair.

Rattling noise: dishes, silverware, or debris

A rattling noise is the most common and the easiest to fix. The usual culprit is dishes knocking together. If cups or bowls are nested, they can rattle against each other when water pressure shifts. The dishwasher third rack explained article shows how a third rack keeps utensils separated and prevents rattling.

Silverware is another common source. If forks and spoons are stacked in the basket, they will clatter. The dishwasher silverware basket page explains how to load silverware so pieces do not nest.

A small object like a bottle cap or a broken piece of glass can rattle in the sump at the bottom. This often produces a noise that comes and goes with the spray. If you hear a rattling that is not related to dishes, check the sump area for loose objects.

Humming or buzzing noise: pump or valve

A low hum during the drain cycle is normal, but a loud hum, a buzz, or a grind when draining is not. The drain pump moves water out through the dishwasher drain options. If something blocks the pump, it will struggle, and you will hear a pronounced hum. You may need to clear the blockage following troubleshooting steps.

A buzzing noise at the very start of the cycle, before water enters, often comes from the water inlet valve. The valve opens to let water in, and debris or hard water scale can make it stick, producing a buzz. The dishwasher inlet valve explained page describes how the valve works and how to check it.

A deep hum that changes pitch during the wash can come from a circulation pump that is wearing out. This is more likely in older machines. If the dishwasher is more than eight years old, a persistent hum may signal that the motor is near the end of its life.

Why some dishwashers are louder than others

If you are buying a new dishwasher because the noise is too much, look for the decibel rating. The dishwasher db rating explained article explains how the rating works and what it means in practice. Most modern dishwashers run between 38 and 50 dB, and some models are quieter than others.

Quieter models typically use an inverter motor, which is often quieter. They also add insulation around the tub. Look for models with more insulation for quiet operation.

A model that is quiet at purchase can become noisy later if the door gasket wears out. Gaskets seal the tub, and a worn gasket lets sound escape. If the noise seems to come from the door, check the gasket for cracks.

What to pick for your use

Questions

Why does my dishwasher make a grinding noise when washing?

A grinding noise during the wash usually means the spray arm is hitting something or the circulation pump has debris in it. Spin the spray arm by hand to see if it moves freely. If it does, check the filter for cracks and remove any debris that may have reached the pump.

Why is my dishwasher rattling?

Rattling is often caused by dishes or silverware clashing during the wash. Reposition items so they do not touch. If the rattling continues, check the sump and filter for small objects like bottle caps or broken glass.

Is a humming noise coming from my dishwasher normal?

A low hum from the pump is normal, but a loud or persistent hum can indicate a blocked drain pump or a worn circulation motor. If the hum happens when draining, check the drain pump for blockages. If it happens during the wash, the motor may be failing.

Can a noisy dishwasher be fixed, or should I replace it?

It depends on the cause. Loose debris, a blocked filter, or a foreign object in the pump are easy to fix. A worn pump bearing or failing motor is more expensive to repair. For an older dishwasher, replacement may offer a quieter operation with better efficiency.

What is the quietest dB rating for a dishwasher?

The quietest current dishwashers are rated around 38 dB. A rating of 44 dB or lower is considered very quiet. The decibel rating article gives more detail on what the numbers mean.

Does the type of dishwasher tub affect noise?

Yes. A stainless steel tub absorbs sound better than plastic, so it helps reduce overall noise. The article comparing interior materials gives more details.