During a drain test on a wet-pipe system, which outcome would indicate an issue requiring corrective action?

• A. Water drains completely with no residual water
• B. Water drains with minor leaks
• C. Water remains in piping after discharge
• D. Discharge outlets are obstructed

Answer: (C)

The main idea is that a drain test should leave the piping completely empty after discharge. If water stays in the piping, it shows the system cannot drain fully, signaling a problem that needs fixing. This usually means something is blocking or restricting the drain path, a valve may be closed or not functioning, or venting isn’t allowing air to escape. Any of these issues prevents complete drainage and warrants corrective action, such as clearing the drain, repairing or reopening the valve, or correcting venting. In contrast, full drainage with no water left is the desired result, and only minor, non-fluid-impairing leaks or an unobstructed discharge would not indicate a failure of the drain to drain.