Pool leak detection: what to know

What the job involves, what changes the price, and what to ask a pro.

What pool leak detection is

Pool leak detection finds where water is escaping from a pool, whether it is the shell, a fitting, a buried line or the equipment. Owners call when the water level keeps dropping faster than evaporation explains, so the leak is found before it does more damage.

Signs you need it

  • The water level keeps dropping faster than evaporation explains, even after a rain or with the cover on
  • Wet spots or soggy ground appear near the pool, the equipment pad or the buried lines
  • The filter pressure or the flow at the returns changes without a clear reason
  • Air bubbles or cloudy water appear around a return, a skimmer or a light fixture
  • The chemistry needs constant adjustment with no clear cause
  • The coping has shifted or new gaps have opened around the pool edge

What the pro does

  • Run a bucket test to separate evaporation from leakage, and log the water level over a set period
  • Check the equipment, valves and unions for drips with the pump running and with it off
  • Run a dye test around the skimmer, returns, light niches and the shell to find the leak point
  • Pressure test the lines with the pump off, sealing the ends and watching the gauge for drops
  • Use listening devices on the lines and the shell to pinpoint a leak in buried plumbing
  • Report the location, the test results and the repair options in writing

What changes the price

Every job is different, so we do not publish prices. These are the things that move the quote up or down.

  • Whether the leak is in the shell, a fitting, a buried line or the equipment, since each needs different tests
  • How long the detection takes, which depends on how many lines and fittings must be tested
  • Whether the pool must be drained or partly drained for the test to be accurate
  • Access to buried plumbing, the equipment pad and fittings behind walls
  • Whether the pro must cut or dig to find the leak, and how much restoration that needs
  • Pool age, surface type, and the number of returns, skimmers and light niches to check

What a written quote should spell out

  • The tests the pro will run, such as bucket, dye, pressure and listening tests
  • What the pro will check at the shell, the fittings, the equipment and the buried lines
  • Whether a repair is included, or the detection stands as a separate job
  • What happens if the leak is in a buried line that needs digging
  • The written report, with photos and the test results
  • Whether a follow-up test after the repair is included

Questions to ask before you hire

  • Which test will you run first, and why?
  • Will the pool need to be drained for the test to work?
  • How do you find a leak in a buried line without digging up the yard?
  • What will you show me at the end, and do I get a written report?
  • How long will the test take, and when can you start?
  • If you find the leak, is the repair something you do, or do you refer it out?
  • Do you test the equipment and fittings as well as the shell?

Red flags

  • They say the pool leaks without running any test
  • They sell a dig or a drain before they have located the leak
  • They do not show the test results or mark the locations on a report
  • They name one location with no proof behind it
  • They will not explain the test method they use

What you can do yourself

A homeowner can run a simple bucket test by filling a bucket with pool water, setting it on the top step, and marking the pool and bucket water levels over a few days. Do not dig, pressure test lines, or open the equipment or buried plumbing yourself, and do not work near any electrical connection. Call a pro to locate and confirm the leak, and to repair it.

Licenses and permits

Leak detection often involves testing plumbing and equipment, and any repair that touches buried lines, excavation or electrical work may need a licensed trade or a permit. Check with your state or local licensing agency to see which licenses and permits apply to the pro you hire.

Pool leak detection questions

Is a leak detection test accurate?

The tests can be reliable when they are run in the right order and the pool is at a steady level. Ask the pro to show the test results and explain how the leak was confirmed, not just where it is.

Can a pool leak be fixed without digging?

Some leaks in the shell, the skimmer or a fitting can be fixed from inside the pool or from the equipment side. Buried lines often need digging, so ask the pro which route the leak needs.

How do I tell whether the leak is in the pool or in the equipment?

A pro can test the equipment and the lines separately with the pump on and off, which narrows down where the water is going.

About this guide

This national guide is written and checked by infinibell. Rules and conditions differ by place, so local pros are credited on guides for the cities they serve, not on national ones.

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