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

The Massachusetts Plumbing Code stipulates that the maximum permissible water temperature for a residential hot water system is 140 degrees Fahrenheit. This temperature is recognized as safe for domestic use while also preventing the risk of scalding, which can occur at higher temperatures.

At 140 degrees Fahrenheit, water can cause burns, but the risk is significantly reduced compared to temperatures above this threshold. This is particularly important for households with young children or elderly individuals, who are more susceptible to burns. Setting the standard at this temperature helps balance the need for hot water (for sanitation and comfort) with safety considerations.

Higher temperatures, such as those offered in the other choices, pose increased risks for accidental burns and scalding injuries. Hence, maintaining the maximum temperature at 140 degrees serves to protect residents while still allowing for effective water heating in homes.