Hard Water and Dishwashers: How to Prevent Limescale Buildup

If you live in a hard water area, you're probably familiar with the telltale signs—cloudy glassware, soap scum, and that chalky residue on taps and appliances. Unfortunately, your dishwasher isn’t immune. Over time, hard water can cause limescale buildup inside the machine, clogging essential components, reducing efficiency, and shortening its lifespan. But the good news is, with a few simple strategies, you can keep your dishwasher running smoothly and your dishes sparkling clean.

What is Limescale and Why Does it Matter?

Limescale is a hard, chalky deposit that forms when minerals in hard water—mainly calcium and magnesium—settle on surfaces. In a dishwasher, this buildup can affect internal components like the heating element, spray arms, and filters, making it harder for your machine to clean properly and forcing it to use more energy to heat water. In severe cases, it can even lead to premature appliance failure.

Signs of Limescale in Your Dishwasher

• Cloudy or streaky glasses and dishes

• White residue on cutlery or plastic items

• Film or chalky buildup inside the dishwasher

• Reduced water flow or spray performance

• Longer or less effective wash cycles

Tips to Prevent Limescale Buildup

1. Use Dishwasher Salt Regularly

Many modern dishwashers—especially in hard water areas—have a built-in water softener unit. Using dishwasher salt helps this system work effectively, preventing mineral deposits from forming. Always check your salt level and top it up regularly, especially if you notice a decline in cleaning performance.

2. Add Rinse Aid

Rinse aid helps water slide off dishes and reduces spotting and filming caused by hard water. It also assists with faster drying and keeps your glassware looking crystal-clear. Some dishwashing tablets contain rinse aid, but using a separate dispenser often delivers better results in hard water regions.

3. Run a Monthly Cleaning Cycle

Using a dishwasher cleaner once a month can help remove any limescale that has already formed. These cleaners are specially designed to tackle mineral buildup inside the machine—just pop one in and run an empty hot wash.

4. Choose the Right Detergent

Look for dishwasher detergents that are formulated for hard water. These products contain ingredients that help counteract the effects of mineral buildup. Avoid using regular washing-up liquid, which can create too many suds and worsen the problem.

5. Clean Filters and Spray Arms

Regular maintenance is key. Remove and clean the dishwasher filter every couple of weeks, and check that the spray arms aren’t clogged. Soak them in a vinegar solution if needed to remove mineral buildup.

6. Consider a Water Softener

If you’re constantly battling limescale, installing a whole-house water softener could be worth the investment. It helps not just your dishwasher, but all water-based appliances and fixtures in your home.

Keep Your Dishwasher Performing at Its Best

Whether you’re using one of our Built-In Dishwashers for a sleek, integrated kitchen or a Freestanding Dishwasher for more flexibility, regular care and attention will help prevent the damaging effects of limescale. By taking a proactive approach to maintenance, you’ll extend the life of your machine and keep your dishes looking their best.

Ready to upgrade or protect your current appliance from hard water damage? Browse our collection at Home Appliances Warehouse Ltd for durable, high-performance dishwashers that stand up to even the hardest water.