Pipe testing of pool plumbing lines confirms which buried pipe is leaking -- using air pressure to isolate each line individually before any digging begins.
When a homeowner's pool is losing water but no structural leak is found at the fittings inside the pool, the next step is checking the plumbing. Pool plumbing runs underground -- beneath the deck, the landscaping, and sometimes under the house -- and a break anywhere along those buried lines can drain significant water without any visible sign at the surface. Pipe testing of the plumbing lines is how that's confirmed.
Pipe testing answers one specific question per line: does this pipe hold air pressure, or does it leak?
A line that holds pressure is intact. A line that loses pressure has a break somewhere in it. The test doesn't locate the break -- it confirms the break exists and identifies which line is broken. That's the critical piece of information needed before any locating work or excavation begins.
The line is intact. No break in this pipe. The leak is elsewhere.
The line has a break. This pipe is leaking somewhere underground.
Step 1 -- Plug the lines at the pool. Rubber test plugs are inserted into each pool fitting -- return jets, skimmer inlets, main drain, and cleaner port -- sealing the line at the pool end. This isolates the underground section of pipe between the pool and the equipment pad.
Step 2 -- Connect the manifold at the equipment pad. A pressure manifold connects to the plumbing at the pump and filter pad. This allows the technician to pressurize each line individually through the manifold while watching a pressure gauge.
Step 3 -- Pressurize each line and watch the gauge. Air is introduced into one line at a time at low to moderate pressure. The technician then monitors the gauge over a set period. If pressure holds, the line is good. If pressure drops, the line is leaking.
Step 4 -- Document which lines fail. Each line is tested individually and recorded. It's possible for more than one line to fail -- pools sometimes have multiple broken pipes. All failing lines are documented before any locating work begins.
A failed pressure test confirms a pipe break -- but it doesn't tell you where along the pipe the break is. That's the job of trace gas equipment. Once pipe testing identifies the leaking line, trace gas (5% hydrogen / 95% nitrogen blend) is introduced into that pressurized line. The gas escapes at the point of the break underground. Small holes are drilled at strategic surface locations to allow the gas to reach the surface, and the technician scans for the strongest signal to identify the general zone of the break.
Understand your pool's water loss pattern -- and whether underground pipe leaks fit the picture.
Leak and Subsurface Locators tests every pool plumbing line individually -- so you know exactly what's broken before any concrete is cut. Call Sandra to schedule.
No, when performed correctly. Testing uses air at pressures within the safe operating range for pool PVC plumbing. A trained technician does not over-pressurize lines. The procedure is non-destructive -- no cutting, no digging, no damage to the pool or deck during the test itself.
If all pool plumbing lines hold pressure, the leak is structural -- in the pool shell itself rather than the underground plumbing. The diagnosis then focuses on the findings from the underwater inspection: skimmer, light niche, return fittings, cracks in the plaster or gunite. No plumbing lines need to be excavated.
Yes, and it's not uncommon. Ground movement, root intrusion, age-related joint failure, and poor original installation can affect multiple lines. Testing each line individually ensures that all failing pipes are identified -- not just the most obvious one. Finding and fixing only one broken pipe when two are leaking leads to a callback and continued water loss.
Yes, when the design allows it. LSL tests pool plumbing lines and water features where test plugs can be installed. Some water feature designs -- such as sheer descent features -- do not allow for plug installation and cannot be isolated for pressure testing. When a water feature is suspected as a source of water loss, the technician evaluates whether testing is physically possible before proceeding.