How to Clean a Dishwasher

A dishwasher cleans your dishes, but who cleans the dishwasher? Grease, food bits, and hard water scale build up inside every machine. This guide shows you how to clean a dishwasher from filter to spray arms, step by step.

You need no special tools. White vinegar, baking soda, dish soap, and an old toothbrush handle the whole job. Set aside thirty minutes.

How to Clean a Dishwasher Filter Step by Step

Start with the filter. It catches food so it never reaches the pump. A clogged filter is the top cause of bad smells and dirty dishes.

Pull out the bottom rack. Find the round filter housing under the lower spray arm. Twist the filter counterclockwise and lift it out. Most models have two parts: a coarse screen and a fine mesh cylinder.

Rinse both under hot running water. Scrub with dish soap and an old toothbrush. Work the bristles into the mesh. Rinse until water runs clear through every hole.

Hold the mesh up to the light. If you see tears or holes, replace the filter. A damaged filter lets food into the pump, which causes bigger problems. Our dishwasher not draining guide covers what happens when food reaches the pump.

Drop the filter back in and twist clockwise until it locks. It should sit flat with no wobble. A loose filter is almost as bad as a dirty one.

Clean the Spray Arms

Spray arms spin and shoot water through tiny holes. Mineral scale plugs those holes over time. Weak spray means dirty dishes.

Remove the lower arm first. It usually pulls straight up. The upper arm under the top rack unscrews or unclips. Check your manual if one resists.

Rinse each arm under hot water. Poke every spray hole with a toothpick or thin wire. Push out the white crusty buildup. Shake the arm near your ear. Rattling means trapped debris is still inside.

Keep rinsing until water flows freely from all holes. Snap the arms back into place. Spin each one by hand. It should turn freely without hitting the racks. Clogged arms force the pump to work harder. That extra strain shortens the life of the motor. A two minute arm check during your monthly filter clean prevents this wear.

Wipe the Door Gasket

The rubber gasket around the door keeps water inside. Its folds trap food and grow mildew. This is where most dishwasher odors live.

Pull the gasket gently away from the tub. Wipe every fold with a damp cloth and a drop of dish soap. Work all the way around the door, top to bottom.

Pay extra attention to the bottom edge. Gunk collects there because water pools. Rinse your cloth often. Finish with a dry wipe so no soap film stays behind.

Check the gasket for cracks or flat spots while you wipe. A damaged gasket leaks water onto your floor. Replacement gaskets are cheap and usually press into a channel with no tools.

Run a Vinegar Wash Cycle

Now descale the inside. Vinegar dissolves grease and loosens mineral scale from parts you cannot reach.

Remove all dishes and racks if they lift out easily. Place one cup of plain white vinegar in a dishwasher-safe bowl. Set the bowl on the top rack.

Run the hottest, longest cycle with no detergent. Let the vinegar do the work. When it finishes, open the door and look inside. The walls should look brighter and feel less slimy.

Two rules. Never pour vinegar straight into the bottom of the tub. The pump can suck it up undiluted. And never mix vinegar with bleach. The fumes are dangerous.

Deodorize With Baking Soda

Vinegar cleans. Baking soda freshens. Use it as the second step, never in the same cycle.

Sprinkle one cup of baking soda across the empty dishwasher floor. Run a short hot cycle with no dishes and no detergent. The baking soda neutralizes odors trapped in plastic parts.

When the cycle ends, leave the door open for an hour. Airflow finishes the job. Your dishwasher should smell like nothing at all. That is the goal. A clean dishwasher has no smell. Crack the door after every wash from now on. Trapped steam feeds the mildew that causes odors.

Fight Hard Water Scale

White film on glasses means hard water. Your area has high mineral content. The vinegar wash helps, but hard water homes need extra care.

Use a rinse aid in the dispenser. It helps water sheet off dishes instead of spotting. Refill it when the indicator window looks empty, about once a month.

For heavy scale, run the vinegar wash monthly instead of quarterly. Some homeowners add a water softener for the whole house. That fixes spots on dishes, shower doors, and faucets all at once.

If scale keeps winning, check your water heater temperature. Water below 120 degrees cannot dissolve detergent fully. That leaves film on everything. Very hard water may need a whole house softener. That one fix helps dishes, laundry, and plumbing at once. For deeper dishwasher problems beyond scale, our dishwasher repair hub covers pumps, heaters, and control faults.

How Often to Clean Your Dishwasher

A simple schedule keeps your machine fresh:

• Monthly: Remove and rinse the filter. Takes two minutes.
• Every one to three months: Run the vinegar wash cycle.
• Every few months: Wipe the door gasket folds.
• As needed: Clear spray arm holes when dishes come out dirty.

Hard water shortens every interval. If your glasses cloud up fast, clean monthly across the board.

A clean dishwasher also breaks down less. Clogs and scale strain the pump and heater. Ten minutes of maintenance beats a repair bill. If your machine already has fault codes, our Bosch dishwasher error codes guide explains what they mean.

Still fighting odors or poor cleaning after a full deep clean? Something mechanical may be wrong. Call +1 (888) 206-0056. Our techs service dishwashers across all areas we serve. For repairs beyond cleaning, see our dishwasher repair hub.