What is the recommended practice for verifying system pressure before a plumbing inspection?

Using a pressure gauge on the main supply is considered the recommended practice for verifying system pressure before a plumbing inspection because it provides an accurate and direct measurement of the water pressure in the system. This method allows the plumber to identify any potential issues that may affect the performance of the plumbing system, such as excessive pressure that could lead to leaks and fixture damage, or inadequate pressure that could cause poor water flow.

A pressure gauge placed on the main supply line provides a clear numerical reading, which is essential for understanding the system's current state. This measurement can guide necessary adjustments or repairs before the inspection takes place. Such a practice ensures that the plumbing system operates effectively and within code requirements, ultimately leading to a successful inspection outcome.

Visual inspection of the meter may not provide a definitive understanding of the system pressure, as it might not reflect transient changes or specific issues affecting individual fixtures. Testing at each fixture is more tedious and may not offer a comprehensive view of the entire system's pressure. Similarly, removing and testing the aerator focuses on a specific component rather than assessing the overall system pressure. Therefore, using a pressure gauge on the main supply is the most effective and reliable method.