How to Descale a Dishwasher and Remove Limescale
Sydney's tap water is moderately hard, and over time, mineral deposits (limescale) build up inside your dishwasher's spray arms, heating element, and interior walls. This reduces cleaning performance and can shorten the machine's life. Here's how to fix it.
Signs Your Dishwasher Has Limescale Buildup
- White chalky residue on glasses and dishes
- Cloudy film on stainless steel cutlery
- Streaks or spots on glassware even after washing
- Reduced water pressure from spray arms
- Longer wash cycles or reduced cleaning results
How to Descale Your Dishwasher
Method 1: White Vinegar (Free & Easy)
- Remove all dishes from the dishwasher
- Place a dishwasher-safe bowl filled with 2 cups of white vinegar on the bottom rack
- Run the hottest cycle available (usually 70°C or Sanitise)
- Do NOT add dishwasher detergent — vinegar is the cleaning agent
- Wipe down the interior with a damp cloth when done
Method 2: Citric Acid (More Effective)
- Add 100g of food-grade citric acid to the bottom of the empty dishwasher
- Run a full hot cycle
- Rinse by running a quick cycle without any cleaning agent
Method 3: Commercial Descaler
Products like Finish Dishwasher Cleaner or Citrus Degrease are designed specifically for dishwashers. Follow the product instructions. Use monthly if you have hard water.
Preventing Limescale Buildup
- Always use rinse aid — it prevents water spots and mineral deposits
- Keep your salt dispenser topped up (if your dishwasher has one)
- Run a hot cycle weekly rather than always on eco
- Use quality dishwasher tablets with built-in scale protection
When to Seek Help
If descaling doesn't improve results, the spray arms may be blocked. Oceania Appliances can help you assess whether a repair or replacement is the better option. Call (02) 9757 4888.