A skimmer line is a suction line -- and skimmers can have multiple ports. Missing an equalizer port or a secondary connection will fail a good pipe every time.
Learn the H.U.N.T.E.R. Method →A skimmer line is pressure tested by cleaning the skimmer well, plugging the suction port, isolating and plugging any equalizer or secondary port, isolating the skimmer line at the equipment pad, applying controlled pressure, and monitoring the gauge. A pressure drop may point to a suction line leak -- but the technician must first rule out a leaking plug, cracked skimmer body, equalizer port bleed, bottom-port leak, or pad valve not fully closed. Dye testing handles the skimmer body; pressure testing handles the buried pipe.
Skimmer body leaks -- throat separation, skimmer-to-shell seam, faceplate, gasket, screw holes, bottom port socket, equalizer port -- are confirmed by dye testing in still water with the pump off.
Skimmer line leaks -- the buried suction pipe between the skimmer and the pump -- are confirmed by pressure testing the isolated pipe after plugging the skimmer ports.
A positive dye test at the throat does not clear the suction line. A passing pressure test does not clear the skimmer body. When both issues may be present, both tests are needed.
Not all skimmers are the same. Before testing, the technician must identify every port in the skimmer well and account for each one. A missed port will fail the pressure test regardless of pipe condition.
The most common setup. One suction port connects to the underground pipe. Plug it, isolate at the pad, test.
A second port on older skimmers connects to the pool at a lower level to equalize suction if water drops. Must be plugged or capped before testing.
Some skimmer systems connect to the main drain through the skimmer. This must be identified and isolated -- or the test will lose pressure through the drain line.
Some skimmers have secondary ports that were capped, abandoned, or repurposed. Identify their current condition before testing.
Before plugging anything, look inside the skimmer well. Count the ports. Identify each one: suction port, equalizer port, main drain connection, or capped secondary. Know what you're sealing before applying pressure.
If water level is stopping near the skimmer or the customer reports pump air, dye test the throat, seam, faceplate, and bottom port area with the pump off before moving to pressure testing. This separates body leaks from pipe leaks.
Turn off the pump. Remove the skimmer basket. Clean the bottom of the skimmer well enough to access and inspect the suction port and any secondary ports. Inspect the skimmer body interior for cracks before plugging.
Plug the suction port with the correct size plug, fully seated. Plug or otherwise isolate the equalizer port if present. Account for any main drain connection or secondary port. Confirm every plug is secure before applying pressure.
Close the skimmer valve at the pad. Verify it is fully closed -- a valve that is partially open will bleed pressure silently. Connect the test rig to the skimmer line at the pad side.
Bring the line to controlled test pressure. Skimmer lines are suction-side plumbing and often connect to plastic skimmer bodies -- use conservative pressure. Note the starting pressure. Monitor the gauge.
A cracked skimmer body can bleed a pressure test silently, making it look like the underground pipe is broken.
Use acoustic listening, trace gas, or pipe camera to locate the underground break before recommending excavation. Repair the confirmed source. Pressure test again. Document all results.
Ask about pump air, prime loss, water level near the skimmer, and whether the skimmer was patched before. Post-patch air problems suggest the pipe, not the throat.
Identify skimmer type, all ports (suction, equalizer, main drain connection), valve layout, and any prior skimmer repairs before testing.
Dye test the throat and body first. If negative, move to pressure testing the isolated suction pipe. Separate body leaks from pipe leaks before testing.
Plug every skimmer port, isolate at the pad, apply conservative pressure, and check plugs, equalizer port, pad valve, and skimmer body if the gauge drops.
Confirm line failure after setup verification. Use a locating tool to find the break underground before recommending any demolition.
Repair the confirmed source. Retest. Document plug locations, start PSI, end PSI, and test duration for both the failing and passing tests.
Plugs the main suction port, misses the equalizer port, gauge drops, calls the underground skimmer line broken. Or patches the throat, doesn't test the pipe, and wonders why the pump still pulls air.
Identifies every skimmer port before plugging. Tests the body with dye first, then the pipe with pressure. Understands that a cracked skimmer body can fail a pressure test without the underground pipe being involved at all.
Jeff David is the founder of Leak Business Academy, LLC and Leak and Subsurface Locators, LLC. He is a licensed pool contractor in Florida and an FSPA Palm Beach board member. Jeff teaches the H.U.N.T.E.R. Method -- including the critical difference between skimmer body leaks and skimmer suction line leaks, and why identifying every port before pressure testing is essential to a valid test result.
LBA training covers the complete skimmer inspection workflow -- body dye testing, port identification, pressure testing the suction line, and the locating tools used when a line fails.
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