Plumbing
The Plumbing domain tests supply, drain, waste, vent, fixture, and water-heating components. The exam emphasizes observed performance and safety devices, and the limits of a non-invasive inspection.
What to inspect
Operate fixtures with normal controls and observe flow, drainage, leaks, and obvious cross-connections. Inspect visible supply and drain lines, traps, venting, shutoff valves, sump pumps, and the water heater. For water heaters, check the TPR valve, discharge pipe, fuel shutoff, venting, and drip pan. The TPR discharge should terminate within 6 inches of the floor or exterior, should not be threaded, and should not be trapped.
Limitations
Inspectors are not required to determine water quality, inspect wells or septic systems, test pressure with a gauge, operate shutoff valves, or predict remaining life. Reporting a stain as “active” requires evidence; a moisture meter or further evaluation may be needed.
Worked example
A TPR discharge pipe terminates in the crawlspace and has a threaded end. The inspector reports a safety hazard and recommends correction. Reasoning: a blocked, capped, or improperly terminated TPR discharge can prevent pressure relief and cause tank rupture.
Traps
Opening the TPR valve during inspection, which can cause a leak; calling a water stain active without evidence; missing an S-trap or improper venting; failing to report a missing discharge pipe.