Why Dishwashers Need Cleaning

Dishwashers clean dishes but accumulate grease, food debris, hard water mineral deposits and soap scum over time. A dirty dishwasher cleans less effectively, leaves white residue on dishes and develops odours. Monthly basic maintenance and a quarterly deep clean keeps it working at its best.

Step 1: Clean the Filter (Most Important)

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    Remove and rinse the filter

    The filter is at the bottom of the dishwasher interior. Most modern dishwashers have a twist-and-lift filter — turn it anticlockwise and lift out. There is usually a flat mesh filter underneath as well — lift that out too. Rinse both under hot running water. Scrub with an old toothbrush and dish soap to remove trapped food particles. Rinse thoroughly and reinsert. Do this monthly — a clogged filter is the most common cause of poor washing results and bad odours.

Step 2: White Vinegar Cycle

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    Place a cup of white vinegar on the top rack and run a hot cycle

    Place a dishwasher-safe bowl or cup containing 250ml of white vinegar upright on the top rack. Run the dishwasher on the hottest, longest cycle with no dishes and no detergent. The vinegar dissolves mineral deposits, grease and soap scum from the interior walls, spray arms and components. The hot water disperses the vinegar throughout the machine.

Step 3: Baking Soda Cycle

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    Sprinkle baking soda on the floor and run a short hot cycle

    After the vinegar cycle, sprinkle 2–3 tablespoons of baking soda directly on the bottom of the dishwasher. Run a short hot cycle. Baking soda deodorises and removes staining, leaving the interior looking brighter. Do not combine vinegar and baking soda in the same cycle — they neutralise each other when mixed.

Step 4: Wipe the Door Seal and Exterior

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    Clean the door seal and spray arms

    The rubber door gasket harbours mould and food debris. Wipe it thoroughly with a damp cloth and a little baking soda or kitchen cleaner. Check the spray arm holes — if any are blocked with mineral deposits, poke them clear with a toothpick. Wipe the exterior door with an appropriate cleaner for the material (stainless steel cleaner for stainless, damp cloth for plastic).

Dishwasher tablets vs powder vs gelTablets or pods generally outperform powder and gel for cleaning performance and leave less residue. Use rinse aid (fill the rinse aid dispenser monthly) — it prevents water spots and streaking on glassware and dramatically improves drying. Hard water areas benefit most from rinse aid.

Frequently Asked Questions

Persistent smell after cleaning the filter and running cleaning cycles suggests: mould on the door seal (scrub the inside fold of the rubber gasket), blocked spray arm holes (food debris in the nozzles that recirculates during washing), a drainage issue (old food in the drain hose or pump area), or the drain air gap (on benchtop models) needs cleaning. If the smell is a burning or electrical odour rather than food-related, have the appliance inspected.
Clean the filter monthly. Run a vinegar and baking soda cleaning cycle every 1–3 months depending on usage and your water hardness. Hard water areas need more frequent cleaning as mineral deposits build up faster. Signs you need to clean sooner: white residue on dishes, dishes not fully clean, odour, or water pooling on the floor of the dishwasher.