Ariston storage water heater makes rumbling or popping noises when heating.

Safety first: Turn off power and allow water to cool before draining.

• Drain and flush tank: Connect a hose to the drain valve, open a hot tap, and drain the tank. Then briefly open the cold supply to stir up sediment and flush until water runs clear.
• Inspect element: Remove the heating element and check for heavy scale. Clean or replace as needed.
• Install softening or anti-scale device: Consider a water softener or anti-scale system if your water is very hard.