Explain the purpose of a meter shut-off valve and its typical location.

• A. Controls the main incoming water supply; located at the water meter box.
• B. Allows isolation of a single fixture; located behind each fixture.
• C. It is used to regulate hot water; located at the water heater.
• D. Allows isolation of the water meter for maintenance; located adjacent to the meter on the service line.

Answer: (D)

The key idea is that the meter shut-off valve is there to isolate the water meter so maintenance or replacement can be done without dragging the entire household’s water supply to a stop. When you need to service the meter, you close this valve to stop water flow through the meter itself, making the job safer and cleaner. It’s usually found right next to the water meter on the service line—often inside the meter box or immediately beside it on the house side. This is different from the main shut-off that cuts off water to the whole house, fixture shut-off valves that isolate individual fixtures, or the control at the water heater for hot water.