Pressure and leak testing

Before water

Inspect support, fitting insertion, crimp gauges, clamp position, thread engagement, valve direction and component ratings. Air tests can be hazardous and are not permitted for every plastic system; use only a manufacturer-approved method and pressure.

Water test

Fill partially, confirm vent/overflow, prime pump, open one fixture at a time, purge air and close all outlets. Observe shutoff and whether the pump restarts with no demand.

Hot and drains

Heat water under supervision, check relief/mixing behavior and every hot joint. Fill sinks/pan then release quickly to challenge drains, traps, vents and grey inlet.

Road retest

Inspect after the first fill, full hot cycle, overnight pressure hold, first drive and first rough-road trip. Mark baseline pump cycle and tank-level behavior.

Build rule

If you cannot reach it, isolate it, drain it and explain its pressure/temperature or water-quality job, it is not ready to hide behind a wall.

CHAPTER CHECK

• I can explain the purpose and failure mode of each item in this chapter. • I know which manufacturer limit or water-quality claim controls my choice. • I added the valve, access, drain, measurement or maintenance task to my drawing/checklist.