Inside the house
I can hear running water with everything turned off. What is it?
Hearing water run with every tap and appliance off usually means water is still moving somewhere in the system, which in a Valley home most often means a leak under the slab, a leak in a wall, or a fixture passing water silently. The useful thing about this symptom is that it can be confirmed or dismissed in about ten minutes at the meter.
What it usually is
If water is moving, something is letting it
The sound of running water with all fixtures closed usually means water is still flowing somewhere in the plumbing, either into a leak or through a fixture.
A closed plumbing system is silent. Pressurised water escaping through a small opening is not: it makes a hiss or a rush, and pipe and concrete carry that sound a long way, which is why the noise so often seems to come from a wall with no plumbing in it.
In a slab home the sound frequently comes up through the floor rather than out of a wall. Concrete transmits it well, and people describe it as a stream under the room or a shower running upstairs in a single-storey house.
Be honest about it
What it could be instead
Plenty of household noises impersonate this one:
- A toilet refilling intermittently. The most common single answer, and the cheapest to fix.
- Irrigation on a timer. A drip zone running at night sounds exactly like water moving in the house.
- A water softener or filter regenerating, which happens on a schedule and takes a while.
- Air conditioning condensate, or a pool auto-fill. Both trickle steadily, and both are outside.
Narrowing it down
Working out where the sound is coming from
| What you are hearing | What it suggests | What to check first |
|---|---|---|
| Continuous hiss that never pauses | A leak under pressure | Read the meter with everything off |
| Runs for a while, stops, starts again | A toilet refilling, or a timed appliance | Dye in the toilet cistern, and the irrigation schedule |
| Loudest at the floor, not the wall | A line under the slab | Feel the floor for a warm patch |
Ten minutes, on your own
The ten-minute version
Do these in order and you will usually know which family of causes you are in.
Turn off every fixture, the irrigation and the pool equipment
Everything, so the only thing that can be moving water is a fault.
Put a few drops of food colouring in each toilet cistern
Wait twenty minutes without flushing. Colour arriving in the bowl means that toilet is passing water, and that may be your whole answer.
Read the meter and watch the low-flow indicator
Movement with everything off means water is leaving on your side of the meter.
Listen at the floor and at the walls with the house quiet
An ear to the tile, or a glass against the wall. Note where it is loudest - it is the first thing we will ask.
How urgent is it
Depends entirely on what else is true
Sound alone is not an emergency. Sound plus a warm floor, damp carpet, a stain or a bill that has jumped is a different matter, and that combination is worth shutting the water off for.
If you decide to shut off, the two places are the angle valve in the meter box by the footpath and the house shut-off, usually on the street-facing wall near a hose bib. Worth finding on a calm day rather than in the dark.
If you call us
What we do with a sound
The meter gets read first, because it turns a subjective sound into a measured fact. Then the system is isolated in sections, so the running water can be attributed to the supply into the house, the irrigation, or the pool rather than to all three at once.
Acoustic leak detection is the tool built for exactly this symptom: ground microphones and correlation equipment hear what an ear on the floor can only guess at, and they can compare the same noise at two points to place it along the run.
Straight answers
Running water questions
Can I hear a slab leak?
Often, yes. Concrete carries the sound of pressurised water escaping, which is why people describe a stream under the floor or a shower running in a single-storey house. It is one of the reasons slab leaks are found by ear as often as by eye.
How do I know it is not just a toilet?
Put food colouring in the cistern and wait twenty minutes without flushing. If colour appears in the bowl, that toilet is passing water. It is worth doing on every toilet before anything else is suspected.
The sound moves around the house. Why?
Because pipe and concrete transmit it. The place it sounds loudest is often not the place it is coming from, which is exactly why acoustic equipment and correlation exist.
Should I shut the water off overnight?
If you can hear it clearly and something else is wrong as well - a warm floor, damp flooring, a stain - then yes. If the sound is the only symptom, it can wait for daylight and a proper look.
Homes we listen in
Tell us what the water is doing
Whether the toilets held dye, whether the meter moved, and where the sound is loudest.
Tell us where it is loudest
Which room, floor or wall, and whether the meter moved with everything off.
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What customers in the Phoenix valley have written. The words are theirs, on listings we cannot edit.
“Humberto has been amazing! Prompt, professional, and patient. He has gone above and beyond, taking the time to show me how to operate the water valves and educating me so I can continue to monitor for future leaks. He identified multiple leaks and made thoughtful recommendations.”
“Beto was very professional, thorough and patient in explaining everything he was doing and why. It was an excellent and well worth it experience, and this is saying something for an architect who had a hundred questions!”
“The owner and operator of this company is everything a contractor should be. On time, honest, competent, reachable, comprehensive. Hope to work with him again in the future.”