Running water noise in the house: leak detection services in Nevada

What a slab leak sounds like

A pressurised line with a hole in it makes a steady sound. It is usually a hiss, a faint rushing or a trickle that does not change. It is often clearest at night when the house is quiet and the dishwasher and air conditioner are off.

Under a slab, the sound is muffled by concrete, so it may be heard best at a particular spot on the floor, at a wall where lines rise from the slab, or at the water heater where pipes meet.

Sound travels along pipes, so the loudest place is often not the leak. A sound that seems to come from the garage or a bathroom may start somewhere else.

Sounds that are not a slab leak

Water makes plenty of noise in a house for ordinary reasons. Several of them look a lot like a leak to the ear.

• A toilet with a worn flapper that refills every few minutes.
• A water softener or filter in a regeneration cycle.
• An ice maker or a refrigerator water line filling.
• Expansion and contraction of hot pipes after use, which causes ticking and creaking, not hissing.
• A pressure regulator or valve that hums at certain flow rates.
• Irrigation timers opening valves.

Go through each before assuming the worst. A clear meter result tells you more than the sound.

Listening properly

Choose a quiet time, switch off the air conditioner and appliances, and close the windows. Stand near the water heater and the main shutoff and listen for a minute. Move through the house slowly.

A cardboard tube or a glass held to a wall can help you pinpoint a wall sound, but under-slab sound is harder. If you can hear it only by kneeling and putting an ear to the floor, note the spot and leave it there.

Do not strike pipes or open walls. Mark the location with painter’s tape and tell the technician.

Confirm with the meter

Sound alone is not proof. Turn off all fixtures, check that the meter is still, and watch it for two minutes. If it is moving while you hear the sound, water is escaping. Close the main and check whether the sound stops. If it does, the leak is on the house side.

If the sound continues with the main closed, the cause is not the water line, or the leak is between the meter and the shutoff. Mention it when you call.

The water meter check has the whole routine, including irrigation and pool checks.

Nevada homes and noisy pipes

Many Las Vegas Valley homes have plumbing laid out in a loop under the slab, with lines rising through the floor into walls. Pressure in some neighborhoods can be high enough to make regulators and valves audible. A noisy house is not a leaking one by itself.

In older homes with copper lines, a pinhole under the slab often sounds like a faint, steady hiss that is clearest near the bathrooms or kitchen where lines rise. In newer homes with PEX, water hammer and expansion noises are more common than hissing.

If you are in an HOA community or a townhome, check whether a neighbor’s water is the source. Shared walls carry sound. HOA and townhome slab leaks covers that case.

How a technician places the sound

An acoustic locator is a microphone that picks up leak noise through the floor. The technician moves it along the suspect line and watches for the spot where the signal peaks. The device filters out a lot of background sound, which is why it works where an ear does not.

Before any listening, the hot and cold lines are isolated. If the sound disappears when one line is closed, the technician knows which line to chase. How slab leaks are found describes the combination of tools.

A good locating result does not rely on sound alone. It is confirmed with pressure testing and, where useful, thermal readings.

When to call

A faint sound with a still meter is worth monitoring and re-checking. A sound with a moving meter deserves a call within a day or two. A loud sound with water at the surface should be treated as an emergency. See emergency slab leak service.

If you have a warm spot as well, mention it. The combination of warmth and sound points to a hot-side leak. See warm spot on the floor.

Where you hear it and what that suggests

The location of the sound narrows the possibilities. It will not name the leak, but it does tell you where to start.

At the water heater, a hiss or trickle usually relates to the heater itself or the lines connecting to it. A sound that is loudest near the heater with a warm patch nearby points to a hot-side line.

In a bathroom, the sound often comes from a fill valve, a flapper or a supply line. If the toilet is quiet and the sound persists, the supply lines in the wall or under the floor are next on the list.

In the kitchen, a dishwasher inlet, an ice maker line or a sink supply can sound like running water. Turn off the shutoffs under the sink and see whether it changes.

In a hallway, where no fixtures are close, the sound may be water in a line running under the floor. Hallways often have lines that pass on the way to bedrooms and bathrooms.

Near an exterior wall, the sound may relate to hose bibs and irrigation. Check the outside tap and the irrigation valves.

If the sound seems to come from everywhere, it is likely a pressure effect. High pressure can make an otherwise normal system sound busy, and a technician can check it with a gauge on a hose bib.

A five-minute quiet-house test

Pick a calm moment. Switch off the air conditioner and the fans, close the windows, and ask everyone to stay still. Turn off all taps, the dishwasher, the washing machine and the ice maker.

Walk to the water heater first and listen. Then go to the main shutoff and listen. If you hear nothing at either, move through the house, pausing for ten seconds at each bathroom, the kitchen and the hallway.

Now close the main shutoff. Wait thirty seconds and listen again. If the sound has gone, it was coming from water under pressure in the house-side line. If it has not gone, it was probably something else, such as a neighbor, a fan or a refrigerator.

Open the main again slowly and listen as the pressure returns. A hiss that returns as soon as the main opens is a leak sound. A hiss that appears only after a few seconds may be air in the lines as they refill.

Write down what you heard, where and when. This is useful information. It is also a good test to repeat the next night, in case the first result was affected by something running that you missed.

Recording the sound

A short phone recording can help. Place the phone on the floor or against the wall where you hear it, record a minute of quiet, and note the room and time. The technician can listen to it and may be able to judge whether it is a hiss, a trickle or a mechanical hum.

Record the meter at the same time, and take a picture of the meter face. Together, the sound and the dial are a good first report.

Do not post or share recordings beyond the crew. They are for your record and the technician’s use.

Where this comes up in Nevada

Hearing water with every tap shut is a sign that people report in every region. Local pages that cover the homes and conditions around this topic include Paradise, Sparks, Spring Creek and Dayton.

Local pages say how to rule out other sources of noise. See the areas page for more towns.

Common questions

Related reading: slab leak repair and slab leak detection.