Domestic hot water systems commonly supply which of the following?

Domestic hot water systems primarily serve faucets, which are typically found in kitchens, bathrooms, and other areas where warm or hot water is needed for daily tasks. These systems are designed to provide a reliable supply of heated water for a variety of domestic uses, including handwashing, cooking, cleaning, and bathing.

Faucets are the main point of access for hot water in a domestic setting, making them a crucial component of hot water distribution. In contrast, while hot tubs do use heated water, they usually operate separately from the standard domestic hot water system and often have their own dedicated heating systems. Outside hoses and irrigation systems typically utilize cold water, as they are primarily used for watering plants and cleaning, rather than requiring hot water.

Thus, the focus on faucets highlights the central role they play in the distribution of hot water within typical domestic installations, making this choice the most accurate.