What is the maximum temperature for a residential hot water system?

For a residential hot water system, the maximum temperature typically recommended is 120 degrees Fahrenheit. This temperature is considered safe for most household uses, including bathing and cooking. Keeping the temperature at or below this level helps to prevent scalding injuries, especially for vulnerable populations such as children and the elderly.

Additionally, maintaining water temperature around 120 degrees Fahrenheit can enhance energy efficiency and reduce the risk of bacterial growth in the water heater, particularly the growth of Legionella bacteria, which can thrive in warmer water temperatures.

Tempering the hot water to this level strikes a balance between providing adequate hot water for household needs while prioritizing safety and energy conservation. Higher temperatures, such as 150 degrees or 180 degrees Fahrenheit, can pose significant safety risks due to the potential for severe burns and are generally not recommended for residential settings.