As an expert in the field of water heating systems, I have extensive knowledge about the intricacies of domestic hot water supply. The optimum temperature for domestic hot water is a critical consideration for both safety and energy efficiency.

Firstly, the ideal temperature for domestic hot water is influenced by several factors, including the type of water heater, local regulations, and the specific needs of the household. It is important to balance the need for hot water with the risks associated with scalding and the energy costs of maintaining a high water temperature.

The **American Society of Sanitary Engineering (ASSE)** recommends that water heaters be set at a maximum of 120°F (48.9°C) to prevent scalding. Scalding can occur within just a few seconds of exposure to water above this temperature, particularly for children and the elderly who may have thinner skin and less tolerance to heat. Additionally, the U.S. Department of Energy suggests setting the water heater thermostat to 120°F (48.9°C) to reduce the risk of scalding and to save energy.

However, some households may require a slightly higher temperature for specific uses, such as washing clothes or dishes, which can be achieved by adjusting the settings on the water heater or by using point-of-use heaters at the faucet or showerhead. It's also worth noting that the temperature of water at the tap will be lower than the temperature set on the water heater due to heat loss as the water travels through the pipes.

In terms of energy efficiency, maintaining a lower temperature can significantly reduce the amount of energy required to heat the water. This not only saves on energy costs but also reduces the carbon footprint of the household. According to the Environmental Protection Agency (EPA), setting the water heater thermostat to 120°F (48.9°C) can save up to 7% of the energy used to heat water.

Furthermore, it is essential to ensure that the water heater is equipped with a **temperature-pressure relief valve (T&P valve)** to prevent over-pressurization and overheating. This safety device can automatically release water if the temperature or pressure exceeds safe levels.

In addition to the temperature settings, regular maintenance of the water heater is crucial to ensure its safe and efficient operation. This includes flushing the tank to remove sediment, which can reduce the efficiency of the heater and potentially cause the temperature to rise above the set point.

In conclusion, the optimum temperature for domestic hot water is a balance between safety, comfort, and energy efficiency. While the recommended maximum temperature is 120°F (48.9°C), households may adjust this setting based on their specific needs and the type of water heater they have. It is always advisable to consult with a professional when making adjustments to ensure that the system is safe and compliant with local regulations.

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Temperature: Maintain domestic water heaters at 60--C (140--F) and water delivered at the faucet at a minimum of 50--C (122--F).read more >>