How to Clean a Dishwasher: Filter, Spray Arms & Deep Clean Guide

Your dishwasher works hard. Probably harder than most appliances in your house. But here in Kansas City, we see folks ignore it until there is a problem. They wait until the glasses come out cloudy or the kitchen starts smelling like wet dog.

If you think your dishwasher cleans itself when you run a load, you’re wrong. Over time, grease and food particles build up in the nooks and crannies of the machine. This can turn what is supposed to be your cleaning helper into a breeding ground for bacteria and mold.

We get calls all the time asking why a machine isn’t draining or why the dishes feel gritty. Nine times out of ten, it just needs a deep clean. You don’t need a repairman for this. You just need some white vinegar, baking soda, and about thirty minutes of work.

Here is exactly how we tell our customers to clean their dishwashers.

Why You Need to Clean It

Think about what goes in there. Sauce, grease, little bits of noodles, cheese. Most of that goes down the drain, but not all of it. The sticky stuff stays behind.

If you have hard water, it’s even worse. Mineral deposits build up on the spray arms and the heating element. This stops the water from spraying hard enough to knock the dirt off your plates. If the water can’t spray, the soap can’t work. It’s a bad cycle.

A dirty dishwasher means:

• Your dishes aren’t actually clean
• The motor has to work harder
• You’re wasting energy and water running loads twice

Step 1: Clean the Dishwasher Filter

This is the most important part. If you do nothing else today, clean the filter. Most modern dishwashers have a manual filter.

Here’s how to remove it:

• Pull out the bottom rack and place it aside on the floor.
• Look at the bottom of the tub. You will see a round plastic cap or cylinder.
• Twist it to unlock it. Usually, there are arrows showing which way to turn.
• Pull it up and out. There might be a flat mesh screen under it too. Take that out.

How to wash it:

Take the filter to the kitchen sink. Run it under hot water. If it is covered in slime or grease, use a little dish soap.

Get a soft toothbrush. You need to scrub the mesh screen gently. Don’t use a wire brush or anything hard, or you will tear the screen. If you tear it, big chunks of food can get into the pump and break the whole machine.

Look for calcified bits in the mesh. Scrub them out. If the gunk is really stuck, soak the filter in a bowl of hot, soapy water for 15 minutes.

Once it is clean, put it back. Make sure you lock it in place. If it isn’t locked, it will float away during the wash and hit the spray arms.

Step 2: Check the Spray Arms

Spray arms are usually found one under the bottom rack and one under the top rack.

These arms have little holes in them. That is where the water shoots out. If those holes get clogged with lemon seeds, glass shards, or mineral deposits, the arm won’t spin. If it doesn’t spin, your dishes stay dirty.

Inspect the arms:

Spin them with your hand. They should spin fast and free. If they hit a plate or wobble, fix the loading or check the mount.

Look closely at the holes. Do you see white crust or little bits of food stuck in there?

Clean the clogs:

Use a toothpick or a sewing needle. Poke the gunk back into the arm or pick it out. You can also remove the arms on most models. Usually, there is a plastic nut you unscrew by hand. Take them to the sink and run water through them to flush out the debris.

Don’t use a drill or a metal screw to open the holes. You will change the spray pattern and ruin the pressure.

Step 3: The Deep Clean Cycle

Now let’s remove the grease and odors from the tub. We use simple ingredients for this. Do not go buy those expensive blue tablets at the store. You don’t need them.

Vinegar Wash

Vinegar cuts right through grease and all that hard water buildup.

• Empty the dishwasher, grab a bowl that is dishwasher safe and pour about a cup (8 oz) of vinegar in it.
• Put the bowl on the top rack of the dishwasher and leave it open. Don’t put a lid on it.
• Make sure you don’t add any soap or detergent to the cycle.
• Run the hottest water cycle (typically “Heavy” or “Pots and Pans” setting).

The hot water is going to help spread the vinegar through the entire system.

The Baking Soda Rinse

After the vinegar cycle is done, you might notice a vinegar smell. That’s fine. Now we use baking soda to brighten the interior and scrub away stains.

• Open the door. The tub should look cleaner already.
• Sprinkle one cup of baking soda all over the bottom of the tub. Just dump it right on the stainless steel or plastic.
• Run a short hot water cycle.

The baking soda acts as a mild abrasive. It polishes the surface and neutralizes any leftover acid. When this cycle is finished, the inside of your dishwasher should look brand new.

Step 4: The Seals and Edges

This is the part everyone forgets. The dishwasher door has a rubber seal (gasket) that keeps the water inside. The water from the spray arms doesn’t really hit this area, especially the sides and the bottom lip of the door.

Food splashes here and just sits. It turns into black mold.

Open the door all the way. Look at the rubber seal. Look at the gap between the bottom of the door and the tub.

Clean it:

Mix a little vinegar and warm water. Dip a damp rag or cloth into it. Wipe the rubber seals. You will see black gunk come off. Get your soft toothbrush again. Scrub the crevices around the soap dispenser and the hinges. Wipe everything dry with a paper towel.

If the seal is cracked, replace it. A bad seal can lead to leaks, and water damage on your kitchen floor (and nobody wants that).

Step 5: The Drain Hose and Air Gap

If you have a sink with an air gap (that little silver cylinder next to the faucet), check it. The dishwasher pumps water up to that air gap before it goes down the drain.

If water shoots out of the air gap when the dishwasher drains, you have a clog. Pull the silver cap off. There is a plastic cap under it. Unscrew that. Look inside for food or grease. Clear it out with a paper towel.

If your dishwasher drains directly into the garbage disposal, make sure the knockout plug was removed when it was installed. We see this a lot in new homes. If the sink isn’t draining fast, the dishwasher can’t drain either.

How to Prevent Clogs

You don’t want to do a deep clean every week. To keep the machine running right, you need to change a few habits.

• Scrape, don’t rinse. Modern enzymes in detergent need a little bit of food to work, but you shouldn’t leave big chunks. Scrape the bones and half-eaten sandwiches into the trash.
• Run the hot water. Before you start the dishwasher, run the kitchen faucet until the water is hot. This means the first fill of the dishwasher is hot, not cold. Cold water doesn’t dissolve powder detergent well.
• Use the right detergent. Don’t use cheap gel. It leaves a film. We prefer powder or high-quality pods.
• Load it right. Don’t block the spray arms with a big cutting board. Face the dirty side of the dishes toward the center.

A Schedule That Works

Nobody remembers this stuff. Life gets busy. We built Homevisory for exactly this. We recommend a simple schedule so you don’t forget.

• Weekly: Wipe down the door edges
• Every couple weeks: Clean the filter
• Twice a year: Do the vinegar and baking soda flush

It sounds like a lot, but it takes ten minutes once you get used to it.

Taking care of your appliances is something you need to do on a regular schedule. When you ignore the maintenance, the machine fails. I’ve seen it a hundred times. Use our free Homevisory home task manager to easily stay on top of things like this.

Don’t wait for the pump to burn out. Go check your filter right now. I bet it’s dirty. I follow this exact guide in my own kitchen for my family, and my dishwasher is ten years old and runs like a top.

Clean it today. Your dishes will thank you.