Water Heater Temperature and Sediment

• The U.S. Department of Energy suggests a setting of 120°F (about 49°C), considered safe for most households and lower in scald risk.
• DOE's Energy Saver guide suggests draining a quart of water from the tank every three months to remove sediment, following the manufacturer's directions.
• Sediment is worse in hard-water areas; University of Maryland Extension notes periodic flushing helps remove mineral deposits.
• Check the dishwasher manual first: models without an internal booster heater may need hotter water.

Popping or rumbling usually comes from water trapped under a sediment layer boiling as the burner or element heats it. Rotten-egg smelling hot water can come from a reaction involving the tank's anode rod. Water pooling around the base, rust-colored hot water or a leaking temperature and pressure relief valve need prompt attention from a plumber.