Frigidaire Dishwasher Grinding, Humming, or Rattling

Dishwashers are meant to be quiet, and a sudden grind, a drone or a clatter at night in a small flat is hard to ignore. The good news is that the sound is a clue. A noise during the fill is a different problem from a noise during the drain, and a noise that comes only on the wash phase usually involves the circulation pump or the spray arms.

Grinding that rises and falls

Grinding in the wash phase is often something hard in the pump area. A broken glass chip, a fruit pit, a small bone or a piece of a plastic lid can reach the sump and be chewed by the pump impeller. The chopper section of the filter assembly exists to deal with soft food, not with hard pieces. If you hear a harsh crack-and-scrape, stop the cycle and check the filter basket. Rinsing out what you find is safe.

A grinding that continues even with a clear sump can mean worn pump bearings. This tends to get louder over weeks, and the pump may eventually seize. That is a repair for a technician, since the pump sits beneath the tub.

Humming with no spray

A steady hum while no water moves is the signature of a motor that is energized but cannot turn. It may be a pump impeller jammed by debris or a motor that has lost its bearings. The drain pump produces the same sound if it is blocked. Turn the dishwasher off if it hums for more than a short moment, because an energized stuck motor heats up. Related drain behavior includes the meaning of Frigidaire dishwasher i20, where the tub did not drain completely.

Rattling and clattering

Rattles often come from loading rather than parts. A small cup that tips onto a spray arm, a utensil basket not seated on its rail, or a rack wheel that has come off its track will all clatter. Look at how the arms move; if an arm clips a tall item, you will hear a rhythmic tick. Loose rack stops and a cracked wheel produce a thud when the rack rolls.

If the rattle is in the cabinet instead of the tub, check whether the dishwasher is secured to the counter, whether the supply line or drain hose touches the wall, and whether the toe-kick panel is buzzing.

Buzz and whine during fill or drain

A buzz or whistle during the fill points to the inlet valve, usually when water pressure is high or the valve screen is partly blocked. A burble followed by a gurgle at the end of the cycle is the drain line, sometimes involving the disposal connection. Many apartment buildings in the Bay Area share a drain stack, and a gurgle from the dishwasher can come from air moving through that shared line.

A fan or vent sound

Some Frigidaire models use a fan and a vent to dry dishes. A fan that is struggling or a vent flap that will not close can make a whir or a click, and the controls may show a matching code. The code Frigidaire dishwasher UF refers to a fan that is not running, and Frigidaire dishwasher UO to a vent that will not close.

Owner checks in a sensible order

1. Pause the cycle and listen to where the sound comes from: front, rear or underneath.
2. Open the door and spin both spray arms by hand to see whether they catch.
3. Remove the lower rack and lift out the filter. Take out anything hard or sharp, using care with broken glass.
4. Seat the utensil basket and check each rack wheel.
5. Run a short cycle with the racks empty. If the noise remains, it is not the loading.
6. Note whether the sound happens at filling, washing, draining or drying.

Why the sound often gets worse before the dishwasher fails

Most noisy dishwashers do not fail overnight. A pump that scrapes today usually scrapes louder next month, because debris scores the housing and the bearings loosen with each cycle. A rattle that you ignore can wear the hub of a spray arm or crack a rack wheel. Catching the noise early often means a smaller job, and it spares you a mid-cycle shutdown with a full load of dirty dishes. If you can record a short clip of the sound on your phone, it helps a great deal, since noises are hard to describe in words.

Hard water, scale and quieter operation

Where the water is hard, scale on the pump and arms adds friction and noise. Running a cleaner made for dishwashers every so often keeps the spray holes open, and a light rinse of plates means less food reaches the sump. None of this replaces repair when a part is worn, but it removes avoidable causes of noise before you call, and it makes a real fault easier to hear.

What not to do

Do not reach into the sump by hand if you suspect broken glass. Do not disassemble the pump or lower panel, and do not add a disposal-cleaning product to the tub hoping to loosen debris. If you see smoke, smell burning or notice water on the floor, switch the dishwasher off at the breaker.

When to book

Book when a grind persists with a clear sump, when a hum repeats with no water movement, when the sound grows louder over a few cycles, or when a code appears with the noise. We find the cause first, quote you in writing, and repair nothing without your approval. Your model number is usually on the door edge or tub frame. See Frigidaire dishwasher repair and the Frigidaire dishwashers guide for more detail. The Frigidaire FFBD2420UB is one of the models covered.

Frequently asked questions