How to Clean a Dishwasher (and Keep It Fresh)

What you need to get started

Knowing how to clean a dishwasher starts with gathering the right supplies. The process takes about 15 minutes of active work plus one empty cycle.

• White vinegar (2 cups)
• Baking soda
• An old toothbrush or small scrub brush
• A microfibre cloth
• Dish soap

Step 1: Remove and clean the filter

The filter is the single biggest source of dishwasher odour. It traps food particles that decompose if left too long. Cleaning it monthly at minimum keeps odours at bay.

1. Pull out the bottom rack.
2. Locate the filter at the bottom of the tub (usually a cylindrical piece that twists counterclockwise to unlock).
3. Remove it and rinse under hot running water.
4. Scrub with a toothbrush and dish soap to remove any stuck-on residue.
5. Check the filter housing (the hole it sits in) for trapped food or debris.
6. Replace the filter and twist clockwise to lock.

How often: Check weekly if you run the dishwasher daily. Deep-scrub monthly at minimum.

Step 2: Clean the door seal and edges

The rubber gasket around the door and the edges of the door itself collect grime, mildew, and food splatter that never gets rinsed during a cycle.

1. Open the door and inspect the rubber seal around the entire perimeter.
2. Wipe the seal with a damp cloth and a drop of dish soap.
3. Use a toothbrush to get into the folds where mildew hides.
4. Wipe the top edge of the door and the area where the door meets the tub (this zone never gets sprayed during a wash cycle).

Step 3: Clean the spray arms

Mineral deposits and food particles can clog the small holes in the spray arms, reducing water pressure and cleaning performance.

1. Remove the spray arms if your model allows it (most twist or clip off).
2. Hold them under running water and use a toothpick to clear any clogged holes.
3. Rinse thoroughly and reattach.

How often: Every two to three months, or whenever you notice dishes are not getting clean.

Step 4: Run a vinegar cycle

White vinegar dissolves mineral deposits, cuts grease, and neutralizes odour throughout the entire interior.

1. Place two cups of white vinegar in a dishwasher-safe bowl on the top rack.
2. Run a full cycle on the hottest water setting with the dishwasher otherwise empty.
3. When the cycle finishes, open the door and let it air dry.

Optional follow-up: Sprinkle a cup of baking soda across the bottom of the tub and run a short hot cycle. This brightens the interior and removes any remaining odour.

Step 5: Wipe the exterior

While you are at it, wipe down the exterior door, handle, and control panel with a damp microfibre cloth. For stainless steel exteriors, wipe in the direction of the grain to avoid streaks.

Monthly maintenance schedule

How to keep your dishwasher fresh between deep cleans

Daily habits that prevent buildup:

• Scrape plates before loading. You do not need to pre-rinse, but large food pieces should go in the garbage, not the filter.
• Run the dishwasher regularly. Letting dirty dishes sit for days creates odour. Run it at least every other day.
• Leave the door slightly open after a cycle. This lets moisture escape and prevents mildew in the seal.
• Use the right amount of detergent. Too much creates residue buildup inside the tub.

When a dishwasher needs more than cleaning

If your dishwasher still smells or performs poorly after a thorough cleaning, the issue may be:

• A kinked or clogged drain hose (requires pulling the machine out)
• A failing pump or motor
• Hard water deposits that need a commercial descaler

These are repair issues, not cleaning issues. A monthly cleaning routine prevents most performance problems, but it cannot fix mechanical failures.

How hard water affects your dishwasher

If you live in an area with hard water (common across Durham Region and much of Ontario), mineral deposits build up faster inside your dishwasher. Signs of hard water buildup include:

• White film or spots on glasses and dishes after a cycle
• Chalky residue on the interior walls and door
• Reduced spray arm performance (clogged holes)
• A musty smell that returns quickly after cleaning

For hard water areas, run the vinegar cycle every two to three weeks instead of monthly. You can also add a rinse aid to every load, which helps prevent mineral deposits from forming on dishes and interior surfaces.

If buildup is severe, a commercial dishwasher descaler (CLR or Finish Dishwasher Cleaner) works faster than vinegar for heavy mineral deposits. Run it through an empty hot cycle according to the product directions.

Part of a bigger kitchen routine

A clean dishwasher is one piece of a well-maintained kitchen. If you are tackling appliances, you might also want to clean your oven racks or glass stovetop.

For a full kitchen reset that covers all appliances and surfaces, a professional deep clean handles everything in one visit without you spending your weekend elbow-deep in a filter housing.