Swimming pool plumbing inspection is a visual, non-invasive assessment of the suction lines, return lines, valves, fittings, and related equipment that circulate water through the pool’s filtration system.

How Pool Plumbing Works

A pool’s plumbing is divided into two zones: suction-side and return-side. Suction lines pull water from the skimmer and main drain through PVC pipes to the pump and filter. Return lines then push the filtered water back into the pool through wall-mounted return jets distributed around the pool perimeter. Understanding this flow path is essential for identifying where problems may exist.

Key Plumbing Components to Inspect

  • Skimmer and main drain — should be clear of blockage and debris; skimmer weirs, baskets, deck covers, and flow-adjustment devices should be installed.
  • Suction and return lines (PVC pipe) — check for leaks, adequate support, and signs of calcification, corrosion, or deterioration.
  • Valves — all valves should be fully open during operation; the “off” indicator on multi-port or three-way valves shows which line is closed.
  • Pump and strainer pot — the centrifugal pump should be secured to its base and operating quietly; the hair and lint strainer basket should be clean.
  • Filter system — air pressure-relief valves should be installed on all pressure filter tanks; tanks should be accessible and properly sealed with no leaks.
  • Heater — should be installed downstream of the pump and filter, with check valves between the heater and filter.

Water Flow Adequacy Checks

To confirm functional water flow through the plumbing system, verify the following:

  • The water level is sufficient for proper skimmer operation.
  • No water leaks exist at plumbing connections or equipment.
  • No trapped air is in the system (air at the filter tank should be purged routinely).
  • No scale-causing clogging or restriction of water flow from chemistry imbalance.
  • The pump’s total dynamic head (TDH) pressure matches approved designs.

Identifying Plumbing Leaks

Air bubbles rising from returns or the pool floor are a telltale sign of suction-side air leaks. Other indicators include wet spots or algae growth in areas that should be dry, settling or sinking of the deck, and gaps between the skimmer and pool wall. The bucket test is a standard first step: place a 5-gallon bucket on the pool step, fill it to match the pool water level, turn off the pump, and compare levels after 24 hours — if pool water drops more than the bucket water, a leak is likely.

For more precise identification, a dye test can be performed near suspected areas with the pump off and water still; dye drawn into a crack or opening confirms the leak location. Common leak points include around pool lights, return fittings, skimmer boxes, and the main drain.

Reporting Deficiencies

Under InterNACHI’s standards, the inspector should report as in need of correction:

  • Observed indications of active pool or spa shell leaks
  • Damaged or faulty drain covers, pumps, heaters, or filter housings
  • Inadequate drainage
  • Damaged water line tiles

Keep in mind that pool plumbing inspection is limited to visible, accessible components — inspectors are not expected to perform invasive testing, pressure testing of buried lines, or predict future conditions. When plumbing concerns exceed the scope of a visual inspection, recommend evaluation by a qualified pool contractor