Clean Inside a Dishwasher: Tub, Gasket, and Interior Surfaces

Why cleaning the interior matters

Over time, every dishwasher accumulates food particles, grease, soap scum, and minerals from hard water. These residues cling to the tub, the rubber gasket around the door, and the spray arms. If left unattended, they can cause musty odors, visible film on dishes, and even slow down the machine's ability to clean effectively. A neglected interior can also become a breeding ground for mold and bacteria, which is especially concerning for households with children or allergy sufferers.

Regular cleaning of the tub, gasket, and other interior surfaces is a simple way to keep the dishwasher operating at its best. It also helps you catch small problems early, such as a cracked gasket or a clogged spray arm, before they turn into expensive repairs. If you already notice a musty smell or white residue on your dishes, it is a clear signal that the interior needs a thorough wipe-down. For more on dealing with persistent smells, see dishwasher odors.

What you'll need

Gather a few basic supplies before you start. A soft sponge or microfiber cloth works well for wiping surfaces without scratching them. A mild liquid dish soap or a cleaner specifically formulated for dishwashers is safe on the interior finishes. For descaling, you will need either a commercial dishwasher descaler or citric acid powder, both of which are available at most grocery stores or online. An old toothbrush or a small nylon brush helps dislodge food debris from tight spaces like the spray arm nozzles and the gasket folds.

You may also want a pair of rubber gloves to protect your hands from hot water and any cleaning agents. Finally, keep a dry cloth nearby to wipe down surfaces after cleaning. Avoid abrasive pads, steel wool, or harsh chemicals like bleach, as these can damage the tub, gasket, and spray arm coatings. If you have a stainless steel interior, the same caution applies; check the stainless steel interior vs plastic guide for specific care advice.

Prepare the dishwasher for cleaning

Start by unloading all dishes, cutlery, and any removable accessories. Slide out the bottom rack and set it aside. Next, locate the filter assembly, usually at the bottom of the tub. Remove it according to the instructions in your owner's manual. Place the filter in a bowl of warm, soapy water to soak while you work on the rest of the interior. This makes it easier to scrub away trapped food and grease later.

Inspect the spray arms for any debris or mineral deposits that might block the jets. Check the door gasket for cracks, mold, or food particles. Also examine the door edges and the area around the detergent dispenser for residue. If your dishwasher is hardwired, turn off the circuit breaker to ensure safety while you are reaching inside. For a portable model, unplug it or disconnect it from the faucet. Taking these preparations seriously makes the actual cleaning quicker and more effective. For a deeper look at the filter, see dishwasher filter cleaning guide.

• Unload all dishes and remove the racks.
• Take out the filter and soak it in warm soapy water.
• Inspect spray arms and gasket for residue or damage.
• Turn off power if hardwired; unplug portable units.
• Lay out your cleaning supplies within easy reach.

Wipe the door gasket and edges

The rubber gasket that lines the door is a high-traffic area for moisture and food debris. Mold and mildew often develop in the folds, especially if the dishwasher door is left closed for long periods. Dampen a soft cloth with warm water and a drop of mild detergent, then gently wipe the entire gasket, paying attention to the inner lip and all creases. Use a toothbrush to work into tight corners and remove any dark buildup.

After wiping, go over the gasket again with a clean, damp cloth to remove any soap residue. Do the same for the door edges, including the top edge and the area near the hinges. Inspect the gasket for cracks, tears, or warping that could lead to leaks. If you find damage, it is best to replace it promptly. Our door gasket replacement guide covers the steps. Keeping the gasket clean not only prevents odors but also helps maintain a proper seal, which is essential for efficient operation.

Clean the tub and interior surfaces

With the racks and filter removed, you have clear access to the interior walls and the bottom of the tub. Mix a small amount of mild dish soap with warm water. Dip your sponge or microfiber cloth into the solution and wring it out well. Wipe down the side walls, the bottom, and the back of the tub in a circular motion. Focus on areas where you see visible food crust or greasy film. The heating element, if exposed, should be wiped gently and allowed to dry completely before the next use.

Do not forget the detergent dispenser and the area around it. Food and detergent residues can accumulate there and cause the door to stick or the dispenser to clog. Clean the spray arms next. If they are removable, take them off and rinse them under running water. Use a toothpick or a fine wire to dislodge any mineral deposits blocking the nozzles. For a more thorough cleaning, soak the arms in a vinegar solution for a few minutes. Our spray arm cleaning guide provides additional tips. Once you have finished, wipe down the interior door panel as well, as it often collects splashes.

Descale to remove mineral deposits

Hard water contains calcium and magnesium that can form scale on the tub, spray arms, and heating element. This scale appears as a white, chalky or yellowish crust. It can reduce water flow and heating efficiency, leading to longer cycle times and less effective cleaning. Descaling removes these mineral layers and is an important step in maintaining your dishwasher, especially if you live in a region with hard water.

You can use a commercial dishwasher descaler or a solution made with citric acid. Always follow the product instructions and run an empty hot-water cycle to flush the system thoroughly. Some people prefer to use baking soda as a gentle abrasive for surface stains, but for scale, an acid-based descaler is more effective. For a detailed guide, see descaling with citric acid. If you find yourself descaling frequently, consider investing in a water softener. Built-in softeners are available on some premium models, which you can compare in our best built-in dishwashers guide.

Run a cleaning cycle

After you have manually cleaned the interior, running a dedicated cleaning cycle helps eliminate any remaining residues and sanitizes the internal plumbing. Many dishwasher manufacturers recommend using a commercial dishwasher cleaner tablet or pod, which you place in the main compartment and run on a heavy or normal cycle. These products are designed to break down grease and scale and are safe for the machine's components.

If you prefer a more natural approach, you can place a cup of white vinegar in the top rack and run a normal cycle. However, always check your owner's manual, because some manufacturers do not recommend vinegar due to potential damage to rubber parts. The cleaning cycle should be run with the dishwasher empty. After the cycle finishes, remove any remaining debris from the filter and give the interior a quick wipe-down. Leave the door slightly ajar to allow the interior to air out and dry completely. For more on the pros and cons of different cleaners, see dishwasher cleaner tablets vs vinegar.

Maintenance tips to keep it clean

Preventing buildup is easier than scrubbing it away. ENERGY STAR recommends scraping food off dishes rather than rinsing them before loading. Rinsing wastes water and sends more food residue into the machine, which can accumulate in the filter and on the tub walls. Running full loads is also more efficient, as the dishwasher uses roughly the same amount of water and energy regardless of load size.

Between deep cleanings, wipe the gasket and the filter area every couple of weeks. Remove any large food scraps from the filter after each heavy load. Check the spray arms for debris and clear the nozzles with a toothpick if needed. If you notice recurring odors, address them early. Our mold prevention tips can help you avoid common issues. Finally, inspect the door gasket regularly for wear, and replace it if you see cracks or leaks. For the best loading practices, review our how to load dishwasher for best cleaning article.

What to pick for your use

Questions

How often should I clean the inside of my dishwasher?

It depends on usage and water hardness. A general rule is to wipe the gasket and filter every few weeks and do a deep clean every month or two. If you notice odors or residue, clean it sooner.

Can I use bleach to clean the dishwasher?

Bleach can damage rubber gaskets and metal parts. Use a mild detergent or a dishwasher-specific cleaner instead.

How do I clean the spray arms?

Remove the spray arms if possible and rinse them under running water. Use a toothpick to dislodge debris from the nozzles. Soak in vinegar if they are clogged with mineral scale.

What is the best way to descale a dishwasher?

Use a commercial dishwasher descaler or a citric acid solution. Follow the product instructions. Run an empty hot-water cycle to flush out the solution.

Why does my dishwasher smell even after cleaning?

Check the filter and drain hose for trapped food. The gasket and door edges can hold bacteria. Clean them thoroughly. If the smell persists, run a cleaning cycle with a commercial cleaner. Also ensure the drain hose has a proper high loop to prevent backflow. Our dishwasher drain hose high loop guide explains the correct setup.