What is the recommended temperature for hot water in residential systems?

The recommended temperature for hot water in residential systems is 120°F (49°C). This temperature is considered ideal for providing a balance between comfort and safety. At 120°F, water is hot enough to effectively meet the needs of most household activities such as bathing, dishwashing, and laundry, while still being low enough to reduce the risk of scalding, especially for children and elderly individuals.

Maintaining water temperature at this level also helps in preventing the growth of harmful bacteria, particularly Legionella, which can thrive in water temperatures below 120°F. This temperature is generally accepted as a standard by various health organizations and plumbing codes to ensure both safety and efficiency in hot water systems.

Higher temperatures, such as 140°F (60°C) or 160°F (71°C), while they can provide a better level of bacteria control, pose a significant risk of scalding if a person accidentally comes into contact with such hot water. Therefore, the selection of 120°F strikes a proper compromise in residential settings.