How to Descale a Dishwasher: Step-by-Step Guide

How to Descale a Dishwasher

Limescale — the white, chalky mineral deposit left by hard water — builds up inside dishwashers over time, reducing their efficiency and potentially shortening their lifespan. Regular descaling keeps your dishwasher running at its best. This step-by-step guide explains how to descale your dishwasher safely.

Why Descaling Matters

Sydney's water is classified as soft to moderately hard, but regular use still leads to calcium and magnesium deposits building up on:

• Spray arms (blocking jets and reducing cleaning performance)
• Heating elements (reducing efficiency and increasing running costs)
• Door seals and tub interior
• Filters and drain area

Signs your dishwasher needs descaling include white film on glassware (glass etching), white deposits visible on internal components, reduced cleaning performance, and a musty or stale smell after cycles.

How Often Should You Descale?

For most Australian households: once every 1–3 months, depending on how often the dishwasher is used and your local water hardness. If you use rinse aid and dishwasher salt in the dispenser (available on most European dishwashers), you need to descale less frequently.

What You'll Need

• Dishwasher descaler (commercial product) OR white vinegar
• Bicarbonate of soda (optional)
• Soft cloth or sponge
• Old toothbrush or small brush

Method 1: Descaling with a Commercial Dishwasher Descaler

1. Remove all dishes and utensils from the dishwasher.
2. Remove and rinse the filter under running water. Use a soft brush to clean any food debris from the mesh.
3. Place the descaler product in the dishwasher according to its instructions (usually in the cutlery basket or on the bottom of the tub, not the detergent dispenser).
4. Run a hot cycle (60°C or above) with no dishes inside.
5. When the cycle finishes, wipe down the door seal and edges with a damp cloth.

Method 2: Descaling with White Vinegar (DIY Method)

1. Remove all dishes and clean the filter.
2. Place a dishwasher-safe bowl or cup filled with 2 cups (500ml) of plain white vinegar on the bottom rack.
3. Run a hot cycle (60°C) with no dishes. The vinegar will distribute through the cycle, dissolving limescale deposits.
4. After the cycle, sprinkle 1 cup of bicarbonate of soda on the bottom of the tub and run a short hot cycle. This deodorises and brightens the interior.
5. Wipe down the door seal with a damp cloth.

Note: Do not mix vinegar and bicarbonate of soda in the same cycle. Run them in separate cycles.

Tips for Keeping Your Dishwasher Scale-Free

• Use rinse aid in every cycle. Rinse aid prevents water droplets drying on surfaces and reduces scale formation on glassware.
• Use dishwasher salt if your machine has a water softener dispenser. This is the most effective long-term protection against scale in hard water areas.
• Clean the filter every 2–4 weeks.
• Wipe the door seal monthly with a damp cloth.
• Run a hot 70°C or intensive cycle once a week to prevent buildup.

Service and Appliance Advice

If descaling does not resolve cleaning performance issues, it may be time for a professional service or a new dishwasher. Contact Oceania Appliances for advice on dishwasher care or to browse our current range.

• Phone / WhatsApp: 0422 489 492
• Email: support@oceaniaappliances.com.au