How to Clean Dishwasher Spray Arms

To clean dishwasher spray arms, unscrew or unclip each arm from the dishwasher, use a toothpick or thin wire to poke mineral deposits out of each spray nozzle, soak the arms in a 50/50 mix of warm water and white vinegar for 20 minutes, rinse thoroughly, and reattach. Do this every 3 to 6 months.

The steps

Empty the dishwasher and pull out the racks

Remove the bottom rack and the top rack to expose both spray arms. The lower spray arm sits on the tub floor. The upper spray arm attaches to the bottom of the top rack or to the ceiling of the dishwasher.

Remove the spray arms

Most spray arms unscrew by hand. Turn the center hub counter-clockwise to release the lower arm. The upper arm usually unclips with a quick twist or pulls off a clip. Check your manual if you are not sure which attachment method your model uses.

Poke debris out of each nozzle

Hold the arm up to a light and inspect every spray nozzle. Use a toothpick or a straightened paperclip to push mineral deposits and food bits out of each hole. Work from both sides of the arm so you push the debris all the way through.

Soak in warm water and vinegar

Fill a sink or large bowl with 50/50 warm water and white vinegar. Submerge both arms for 20 minutes. The vinegar dissolves the hard water minerals that a toothpick cannot reach.

Rinse thoroughly under running water

Hold each arm under running water and rotate it so water flows through every nozzle. You should see strong, even spray from each hole. If any nozzle still trickles, poke through it again before reinstalling.

Reattach the spray arms

Thread the lower arm back onto its hub and turn clockwise until snug. Hand-tight is enough, do not force it. Click or clip the upper arm back into place. Spin each arm by hand to confirm it rotates freely without binding.

Why clogged spray arms cause spotty dishes

Dishwashers work by blasting water from the spray arms onto your dishes. Each spray arm has a series of small nozzle holes, and water pumped from the bottom of the tub gets forced through those holes at high pressure. The pressure and the angle of the nozzles are what actually clean the dishes.

When mineral deposits or food particles clog the nozzles, two things go wrong:

Water pressure drops at the affected nozzles, so dishes directly in that spray path do not get cleaned properly.
The spray arm's rotation can slow or stop entirely if enough nozzles clog on one side, because the arms spin from the thrust of water jetting out through the nozzles.

You might clean the filter, use the right detergent, and still have spotty dishes if the spray arms are clogged. This is the next thing to check after the filter.

How often to clean the spray arms

Every 3 to 6 months for most homes. Homes with hard water (above 7 grains per gallon) should aim for every 2 to 3 months. You can also clean them any time dishes come out spotty after you have already ruled out the filter, detergent, and rinse aid.

A quick monthly check is worth 30 seconds. Pull the bottom rack and spin the lower spray arm by hand. It should spin freely. If it feels stiff or you hear rubbing, clean it sooner.

The vinegar soak does most of the work

Poking individual nozzles with a toothpick handles visible food debris, but mineral buildup coats the inside of the nozzles in a way that mechanical poking does not fully remove. White vinegar dissolves calcium and lime deposits on contact.

A 20 minute soak in 50/50 warm water and white vinegar is long enough to break down most buildup. For heavily coated arms, extend the soak to an hour or overnight. The vinegar will not damage plastic or rubber components.

Skip the vinegar only if your dishwasher's manual specifically warns against it. Some commercial models use aluminum parts that vinegar can discolor, but home dishwashers almost always tolerate it fine.

When the spray arms are clean but dishes are still dirty

If you cleaned the filter and the spray arms and dishes still come out spotty, check these in order:

Detergent age. Dishwasher detergent loses effectiveness after about 6 months once opened. Buy smaller quantities you will use up quickly.
Rinse aid. The rinse aid dispenser needs to be full. Rinse aid prevents water from beading on dishes as they dry, which is what causes most spots.
Water temperature. Dishwashers work best with incoming water at 120 degrees. Run the hot tap at the sink for 30 seconds before starting a cycle so the dishwasher fills with hot water from the start.
Loading pattern. Tall items in the front of the bottom rack block spray to the top rack. Plates leaning against each other prevent water from reaching the surfaces. Leave space between items.

How this fits into a maintenance routine

Spray arm cleaning pairs naturally with filter cleaning. When you pull the filter for its 1-2 month cleaning, spin the spray arms and check for clogged nozzles. If anything looks off, do the full spray arm cleaning at the same time. Combining the two tasks adds maybe 10 minutes to the filter job and keeps both components working at peak efficiency.

Frequently asked questions

How do I know if my spray arms are clogged?

The clearest sign is dishes coming out spotty or with food still on them despite the filter being clean. Another sign is uneven cleaning, where dishes on one side of the rack come out fine but dishes on the other side do not. Pull the spray arm out and hold it up to a light. If you cannot see light through some of the nozzles, they are clogged.

Why do dishwasher spray arms clog?

Two reasons. First, hard water leaves mineral deposits inside the nozzle holes over time, narrowing or blocking them. Second, small food particles escape the filter and lodge in the nozzles. Homes with very hard water may see clogging every 2 to 3 months.

Can I put spray arms in the dishwasher?

Yes, but only after you have already poked the nozzles clear and soaked the arms in vinegar. Running them through a normal cycle will not unclog the holes. The vinegar soak is the cleaning step. The dishwasher cycle is optional.

What if a spray arm is cracked?

Replace it. Cracks cause uneven water pressure, which means the opposite end of the arm gets no water and dishes there do not get clean. Replacement spray arms run $20 to $60 depending on the model. Search your dishwasher's model number plus 'spray arm' to find the right part.