Which of the following best describes the location of the shutoff valve in residential plumbing?

The best description of the location of the shutoff valve in residential plumbing is that it is typically found within 3 feet of the water heater. This positioning is critical because it allows for quick access in case of a leak or emergency situation. Having the shutoff valve nearby the water heater ensures that homeowners can quickly isolate the supply of water to prevent damage and facilitate repairs or maintenance.

While shutoff valves can be found in other locations in the home, such as basements or near fixtures, the standard practice emphasizes proximity to appliances like water heaters. This common arrangement also aids in maintaining the plumbing system, allowing easier interventions when necessary. Thus, being within 3 feet of the water heater strikes a balance between accessibility and functionality, which is essential for residential plumbing systems.