Second Opinion Leak Detection: Finding the Leak Others Missed

By Roger Wakefield, Licensed Master Plumber · Published November 11, 2026

Quick answer: What is second opinion leak detection? Second opinion leak detection is a fresh, documented test by a trained leak detection plumber after someone else has already looked for a leak, or already told you that you have one. A good second opinion starts over at the meter, confirms with a pressure gauge whether there is a leak at all, then isolates and listens to find the exact spot before anyone cuts a floor, a wall or a yard.

When should you get a second opinion on a leak?

Get one when the first answer does not add up. That can mean a plumber says you have a leak but cannot show you a test, the water bill is still high after a repair, or you were told to replace the piping under the house without seeing proof.

Roger Wakefield tells a story in his video on what every plumber needs to know about slab leak detection. A plumber told a family they had a leak and started cutting holes at every manifold. The family sent him away. The next day another plumber checked the meter, put a gauge on, shut the meter, turned it back on and told them they did not have a leak. The first plumber had told them they needed to replace all the piping under the house.

Why do leaks get missed or misdiagnosed?

Usually because a step was skipped. Roger says a plumber should not just walk in, look at a water puddle on the floor and decide there is a leak. He has seen a job where rain saturated the ground, water came up through a crack in the floor, and a plumber made a hole in the floor before testing showed there was no leak at all.

Is a meter that is not turning proof of no leak?

No. Roger says that just because a meter is not turning does not mean there is not a leak in the house. It means the leak is not being detected. That is why he always follows up with a gauge, even on newer digital meters.

What does a good second opinion include?

The same steps, in the same order, every time. A careful second opinion usually covers these:

1. Check the meter: see whether it is turning.
2. Put a gauge on: at the house, the valve box, or a hose bib if the vacuum breaker allows it.
3. Shut the meter and wait: if the pressure drops, there is a leak. See water line pressure test.
4. Isolate the system: separate the yard or irrigation from the house, then the hot side from the cold side.
5. Locate and listen: trace the line, then listen along it to pinpoint the leak.
6. Document it: write down what was tested, how much it dropped and when.

How does isolation narrow down a hidden leak?

It shrinks the search. Roger compares leak detection to looking for a needle in a haystack: if you can take out part of the haystack, you know where to look. Closing the valve box tells you whether the leak is in the yard or the house, and shutting the valve at the water heater tells you whether it is on the hot side or the cold side.

What equipment helps find the leak others missed?

Listening equipment and a way to trace the pipe. Roger explains that once you know which system is leaking, you locate the line, then listen along it on the floor, and he says he adds air into the system to listen for a bubbling noise. Read more in acoustic leak detection, line locating for plumbers and how to use air to find a quiet water line leak.

Why does proof matter so much on a second opinion?

Because the homeowner is already unsure who to trust. Roger says a plumber should have a form showing the test on the water, how much it dropped and when, so another plumber can do the same test and see the same result. He also records what he hears through his listening equipment so he can play it for customers. See how to document every leak job.

How much water can a missed leak waste?

A lot. The U.S. Environmental Protection Agency (EPA) says on its WaterSense Fix a Leak Week page that an average household’s leaks can account for more than 9,300 gallons of water wasted every year, and that nine percent of homes have leaks that waste 50 gallons or more per day.

The EPA also says a leak in an irrigation system 1/32nd of an inch in diameter can waste about 6,300 gallons of water per month. If the leak may be outside, see sprinkler and irrigation line leaks and underground water line leaks.

What should homeowners ask a leak detection company?

Ask how they were trained. Roger says homeowners should make sure whoever does their leak detection has been trained the right way. Good questions include:

• Did you go to a leak detection training, and are you certified?
• Will you test with a pressure gauge before you cut anything?
• How will you isolate the yard, the house and the hot and cold sides?
• Will I get a written record of the tests and readings?

Frequently asked questions about second opinion leak detection

These are the questions homeowners and plumbers ask most when a first leak call did not settle things.

Can a second opinion find that there is no leak?

Yes. In the story Roger tells, the second plumber tested the system with a gauge and found there was no leak, after the first plumber had already started cutting holes.

Do plumbers test pressure as part of their job?

Yes. The U.S. Bureau of Labor Statistics plumbers, pipefitters and steamfitters page says they test pressure to ensure that a pipe system is airtight and watertight, and lists troubleshooting skills among their important qualities.

Can fixing a leak lower my water bill?

Often. The EPA says fixing easily corrected household water leaks can save homeowners about 10 percent on their water bills. Read is your winter water bill telling you about a leak.

How do plumbers learn to find leaks others miss?

Hands-on practice. LeakPro leak detection training runs 2 days, typically 6 to 8 hours per day, on a slab with 12 real, live leaks, with a maximum of 3 people per class.

Who is Roger Wakefield?

Roger Wakefield is a licensed Master Plumber with 45 years of experience and a co-founder of LeakPro.

Need a leak found the right way?

Learn the full process in LeakPro leak detection training, start with the signs of a hidden water leak, or contact LeakPro at 1-888-853-2577 to talk it through.