How can you determine if the outlet shut-off valve is leaking?

To determine if the outlet shut-off valve is leaking, observing the behavior of the valve during testing is crucial. If the valve does not open while testing, it could be indicative of a leak elsewhere in the system. This is because, typically, when the valve is functioning correctly, it should allow proper water flow and pressure to be exerted in the desired direction. If it fails to open, it suggests that it may not be sealing correctly or could have a defect, resulting in pressure drops or inefficiencies in system operation.

Staying focused on the other options provides context for understanding why they aren't the defining indicators of a leaking valve. For example, if the gauge needle remains steady, it indicates that there might not be significant pressure fluctuations that would point to a leak. Similarly, if water flows constantly from the valve, it could indicate a more immediate failure, but the destination of that water flow can vary, and it might not necessarily relate to how the outlet shut-off valve is functioning. Lastly, a pressure gauge reading below normal could suggest various issues in the system, not limited to the outlet shut-off valve, making it a less specific indicator.