Leak Detection in Austin & San Antonio

We Find the Leak Before It Finds Your Floor

Slab leaks, leaks inside walls and leaks under the yard, pinpointed with listening equipment, thermal imaging and pressure testing across Austin, San Antonio and Central Texas. You see the evidence and approve the repair before anything gets opened up.

Leak Detection

The Bill Went Up, the Floor Is Warm and Nothing Is Dripping

Most Central Texas homes sit on a concrete slab, and the water lines run underneath it. The clay soil under that slab swells when it rains and shrinks through a dry August, and every cycle flexes the pipe a little. Eventually a copper line rubs through or a joint gives, and the leak runs into the ground where you cannot see it. The first sign is usually a water bill that makes no sense, a warm patch on the tile or the sound of water running when every tap in the house is off.

Radiant locates leaks instead of guessing at them. We isolate the hot and cold sides, pressure-test each, listen for the leak with acoustic equipment and confirm the spot with thermal imaging, then mark it on the floor. From there you get repair options in writing: a direct repair at that spot, a reroute overhead that leaves the slab alone, or, on an older system with a history of leaks, a whole-home repipe. Leaks under the yard are handled the same careful way on our water line repair page, and drain leaks get a camera inspection rather than a shovel. Every option is priced before we start and covered by the Home Comfort Guarantee.

  • Pinpointed, not guessed Acoustic listening, thermal imaging and pressure isolation narrow a leak to a spot, not a room.
  • Every repair option, in writing Spot repair, reroute or repipe, each priced so you can weigh them side by side.
  • Licensed in both cities Master Plumber M-42438 in Austin and M-45619 in San Antonio. Trained, bonded and background-checked.
Radiant plumber carrying leak detection equipment from a Radiant truck

What to Watch For

Signs of a Leak You Cannot See

Hidden leaks rarely announce themselves with a puddle. They show up on the bill and in the floor first.

  • A water bill that jumped for no reason

    Same household, same habits, a bill that climbed. A pressurized leak runs 24 hours a day, and the utility meter counts every gallon.

  • A warm spot on the floor

    Hot-side slab leaks heat the concrete above them. Bare feet on tile find them before anyone else does.

  • The meter turns with everything off

    Shut off every fixture and watch the small dial on the meter. If it moves, water is leaving the system somewhere.

  • Running water you cannot find

    A hiss or rush behind a wall or under the floor when no tap is open. Loudest at night when the house is quiet.

  • Damp baseboards, buckled flooring or mildew

    Water wicks up drywall and lifts laminate long before it pools. A musty smell in one room is a clue worth taking seriously.

  • The water heater never shuts off

    A hot-side leak keeps pulling cold water into the tank, so the burner or elements run constantly and hot water still runs short.

What We Find and Fix

Leaks Under, Inside and Around the House

One licensed plumber locates the leak and repairs it. You do not pay two companies to hand the problem back and forth.

Radiant plumber arriving at a Central Texas home to locate a hidden leak
Leak detection for slab, wall, ceiling and yard leaks before any concrete or drywall is opened.
  • Slab leaks Located from above with acoustic and thermal equipment, then repaired directly or rerouted through the attic and walls so the slab stays intact.
  • Leaks inside walls and ceilings Pinhole copper leaks, failed fittings and sweating lines found with moisture meters and thermal imaging, opened at the leak and nowhere else.
  • Yard and service line leaks The line between the meter and the house, traced and repaired without digging up the whole lawn.
  • Water heater and appliance connections Supply lines, valves and drain pans behind washers, fridges and water heaters, the leaks that quietly ruin a floor.
  • Pressure testing and isolation Hot and cold sides tested separately so we know which system is leaking before we listen for where.
  • The repair itself Spot repairs, reroutes and section replacements, with the new line pressure-tested before we close anything back up.

How It Works

How We Track a Leak Down

Narrow it down first, then listen. Nobody opens a floor on a hunch.

  1. Confirm it at the meter

    We shut the house down, watch the meter and check the water heater. That tells us there is a leak and roughly how big it is.

  2. Isolate hot from cold

    Each side is pressure-tested on its own. Losing pressure on the hot side alone cuts the search area in half before we listen.

  3. Listen and image

    Acoustic equipment follows the sound of escaping water through the slab or wall, and thermal imaging confirms the spot. We mark it.

  4. Price the options

    Direct repair, reroute or repipe, each explained and priced in writing. You choose, then we fix it and pressure-test the result.

Meter Spinning With Everything Off?

That water is going somewhere. Let us find where before it finds your foundation.

What Our Customers Say

Don't just take our word for it — hear from our satisfied customers

J Jeff Fazio
Jeff Fazio 3 years ago
★★★★★
I had Radiant Plumbing replace my tankless water heater, damaged in the Feb. 2021 snowmageddon storm with a new unit. The process was smooth and professional from start to finish. The plumber, James, was extremely knowledgeable and thoroughly explained my options to me. The cost and time to perform the installation were just as estimated. When he was done, James explained how to maintain the system, what service would be needed and how to perform it, and answered all of my engineering geek questions. It was a thoroughly positive experience. I have used several different plumbers in Austin over the past 15 yrs, but my search is over - I will not hesitate to call Radiant next time and would recommend them unreservedly.

8/9/23 Update: I have subsequently used Radiant for a toilet repair, faucet installation (Danny), and drain work (Ezekiel) and they have continued to impress with knowledgeable, friendly plumbers and quality work.
C Cathy McClaugherty
Cathy McClaugherty 5 years ago
★★★★★
We called Radiant Plumbing after we noticed a water leak in our kitchen. We were in a time crunch and they were able to schedule us quickly, before we left for vacation. They sent their representative, Preston Nichols, and he was excellent to deal with! He was on time, skillful, friendly, and very professional. It turned out to be a problem with our dishwasher but Preston was quick to diagnose it and set our minds at ease. While he was here, we mentioned that our one year-old water heater needed to be flushed. Preston was quick to take care of that, as well, saving us time and money in the process. Radiant charged us almost half the price another plumber quoted us for that service! While Radiant Plumbing isn’t our usual plumber, they gained a new customer. We won’t hesitate to call Radiant again in the future based on our VERY positive experience with them.
S Stefano Rosellini
Stefano Rosellini 6 years ago
★★★★★
Had 3 different systems installed by them approx. 3 years ago for a total of approx $20k. I was quite happy with the install until the year later when they came for a maintenance call and started finding deficiencies in their own install. they wanted extra money to address those deficiencies. Now I am in the process of selling my home and an inspector has found a few items that need to be addressed and they will not even look at the report unless I schedule a $139.00 service call. Very poor customer service.. This company does not stand by their work and would not recommend.

I am revising my review of this business from 1 to 5 stars. After my original review I was contacted by the company's service manager and he made sure that I was taken care off. I had a team of 3 technicians coming to my house to double check the system and make the necessary adjustments. I was very satisfied by their attention to details and professionalism.

Maintenance Membership

Join the Care Club

Home maintenance for $9.99 a month.

Care Club members get two HVAC tune-ups and a plumbing safety inspection every year, priority scheduling, no dispatch fees — ever — and 5% off every repair.

  • Priority scheduling
  • Seasonal HVAC tune-ups
  • Annual safety inspection
  • Exclusive member discounts
  • Free dispatch on repairs
  • No long-term contracts

Leak Detection Questions

How can I check for a hidden leak myself before calling?

Do the meter test. Make sure nothing in the house is using water: no running toilets, no ice maker cycling, no irrigation. Find your water meter, usually in a box near the street, and note the reading or watch the small leak indicator dial. Wait 20 to 30 minutes without using any water, then look again. If the reading changed or the dial moved, water is leaving the system somewhere between the meter and your fixtures. Next, walk the house barefoot and feel for warm tile, listen at quiet hours for running water, and check under sinks and around the water heater. If the meter moves and you cannot find the source, that is when leak detection earns its keep.

Why are slab leaks so common in Austin and San Antonio?

Two reasons: how our homes are built and what they sit on. Most houses here are slab-on-grade, with copper or older galvanized water lines run in or under the concrete. Much of Central Texas sits on expansive clay that swells after rain and shrinks hard in a dry summer, so the slab and the soil beneath it move a little every season. That movement works on the pipe year after year until a joint fails or a line wears through against the concrete. Very hard water adds to it, especially on the San Antonio side, where mineral-laden water is tough on copper over decades. None of this means your slab is failing. It means a pipe under it is, and that is repairable.

Do you have to break up my floor to fix a slab leak?

Not always, and often we would rather not. Once the leak is located, there are usually two ways to fix it. A direct repair opens the slab at that one spot, replaces the failed section and patches the concrete. A reroute abandons the leaking run under the slab and replaces it with new line through the attic or walls, which avoids the floor entirely and is often the better choice when the flooring is expensive or the line has leaked before. On an older home with a pattern of leaks, we will also give you a price for a full repipe, because fixing the same system one leak at a time gets expensive. You see all the numbers and pick.

How precisely can you locate a leak?

Close enough to mark the floor or wall and open only that spot. Acoustic leak detection listens for the specific sound of pressurized water escaping a pipe, and the signal is loudest directly over the leak. Thermal imaging then shows the heat or moisture pattern to confirm it. Pressure isolation tells us in advance whether it is the hot or cold system, which keeps us from chasing the wrong line. Depth, slab thickness and background noise all affect the work, which is why we take the time to test rather than rush to a guess. The goal is one small opening, not an exploratory trench through your living room.

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