The answer to 'how does water heater work' is that a water heater uses a heating element or gas burner to heat water stored in a tank. The water is heated to a set temperature, usually between 120-150°F, and is then available for use in sinks, showers, appliances, and other plumbing fixtures. The water heater also has a thermostat to control the temperature and a pressure relief valve to prevent dangerous pressure buildup.
Water heaters come in different sizes, fuel types (electric, gas, tankless), and energy efficiency levels. Proper maintenance, like flushing the tank and checking the anode rod, is important to extend the life of the water heater and ensure safe, reliable hot water for the home.