Heater makes loud popping or crackling noises during heating.

Safety: Turn off power and allow the heater to cool. Close the water inlet before draining.

Steps:

• Drain the tank: Connect a hose to the drain (if present) or remove the cold inlet pipe and drain through a low tap.
• Remove element: Take off the heating element flange and inspect the element for thick, hard scale.
• Descale or replace: Carefully remove scale with a plastic scraper or soak the element in descaling solution. If the element is heavily corroded or deformed, replace it.
• Check magnesium anode: Inspect the magnesium anode rod. If it is heavily consumed, replace it to protect the tank.
• Reassemble and refill: Install new gaskets as needed, refill the tank, bleed air, and restore power.