If you can hear water running with no taps on, check for an obvious cause first: a toilet cistern, a header tank refilling, or a dripping overflow. If none explain it, check your water meter with everything off. Movement points to a pressurised leak in the supply pipework, best confirmed with acoustic listening equipment rather than guesswork.
A sound of running water when every tap is off and no appliance is running is unsettling, mostly because water only moves under pressure or gravity, and if it’s not going where you expect, it’s going somewhere it shouldn’t. This guide covers the harmless explanations, the checks worth running yourself, and how professional acoustic detection narrows a genuine leak down to a specific spot.
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The harmless explanations to rule out first
Not every sound of running water means a leak. Before assuming the worst, it’s worth ruling out the fittings that are designed to move water on their own schedule.
- A toilet cistern with a worn flush valve or ball valve can trickle continuously or refill repeatedly without anyone noticing, especially overnight.
- A cold water storage tank in the loft refilling after normal daytime use can sound like running water for a few minutes at a time.
- An overflow pipe dripping outside, often linked to a stuck ball valve in a tank or cistern, can produce a sound that carries into the house.
- A dishwasher or washing machine on a delayed cycle, or a boiler filling loop left slightly open, can also explain an intermittent sound.
If you’ve checked these and the sound is still there, particularly if it’s constant rather than occasional, it’s time to think about the supply pipework itself.
Why a leak sounds like running water
Mains and internal supply pipework runs under pressure, so a split, a failed joint or a pinhole leak doesn’t just seep quietly, it often hisses, trickles or gurgles audibly as water forces its way out. That sound can travel surprisingly far along a pipe run or through a wall cavity, which is why people often hear it in a completely different room to where the leak actually is.
Pinhole leaks in copper pipework are a common source of this kind of sound, especially in older systems. If the noise seems to be coming from inside a wall near hot water pipework, our guide to pinhole leaks in copper pipes covers the typical causes and warning signs in more depth.
Checking your water meter with everything off
The single most useful test you can run yourself is a water meter check, because it tells you whether water is moving through your supply at all, regardless of whether you can pin down where the sound is coming from.
- Turn off every tap and any appliance that uses water, and make sure nothing is mid-cycle or due to refill (give a toilet cistern time to settle after its last flush).
- Find your meter and note the reading exactly, including any small dials.
- Wait 15 to 30 minutes without using any water anywhere in the house.
- Read the meter again. If it has moved at all, water is passing through somewhere on your side of the system.
For a full walkthrough, including where meters are commonly located and how to read the different dial types, see our guide on how to check your water meter for a leak. A meter that keeps moving with everything off is one of the clearest confirmations that the sound you’re hearing has a real leak behind it.
Where to listen, and what the sound tells you
Before calling anyone, a few minutes of careful listening around the house can help narrow things down, though it’s rarely precise enough to confirm a location on its own.
| What you notice | What it suggests |
|---|---|
| Loudest near the stopcock or where the supply enters the house | Possible leak early in the internal supply run, or on the incoming mains connection |
| Loudest in one particular room, especially a bathroom or kitchen | Likely linked to pipework serving that room’s fittings |
| Sound changes or stops when the stopcock is turned off | Confirms the leak is on your supply side rather than an appliance or tank |
| Sound is constant regardless of time of day or usage | More consistent with a pressurised leak than a tank or cistern refilling on demand |
If turning off the stopcock stops the sound, that’s a strong pointer toward a supply pipe leak, and it’s worth leaving the water off, where practical, until it can be properly investigated.
How acoustic leak detection pinpoints the source
Once the meter and stopcock checks point to a genuine leak, the next step is finding exactly where it is without digging up a garden or lifting every floorboard on a guess. Our acoustic leak detection service uses sensitive listening equipment placed at accessible points along the pipe run, such as stopcocks, valves or exposed sections of pipe.
Water escaping a pressurised pipe produces a distinct sound signature. By recording that sound at two points and comparing the timing, a correlator can calculate the distance to the leak with a good degree of precision. This is usually combined with wider water leak detection methods such as thermal imaging or tracer gas where the acoustic signal is faint or the pipe run is complicated, so the final answer is confirmed rather than assumed.
Older homes across Cornwall and Devon
Granite cottages and older Devon farmhouses often have supply pipework routed through solid stone walls, under flagstone floors, or along routes that were never designed with easy access in mind. That makes acoustic listening particularly useful in this region, since sound travels differently through thick masonry than through modern stud walls, and a leak’s true location can be some distance from where it’s loudest. We hear this most weeks in older properties: a homeowner reports water running somewhere near the kitchen, and the source turns out to be several metres away under a hallway or utility room floor.
Frequently asked questions
Why can I hear water running when no taps are on?
The most common causes are a toilet cistern or ball valve not shutting off properly, a cold water storage tank refilling, or a pressurised leak somewhere in the supply pipework. Because supply pipes run under pressure, even a small split can produce an audible hiss or trickle that carries through walls and floors.
Is a running-water sound with no taps on always a leak?
Not always. A toilet that keeps refilling, a header tank topping up after normal use, or a dripping overflow can all sound like running water without any hidden leak. It becomes more likely to be a leak when the sound is continuous, unrelated to any tank or toilet nearby, and the water meter keeps moving with everything off.
How do I check if it’s a leak using my water meter?
Turn off every tap and appliance, make sure nothing is due to refill, then read the meter, wait around 15 to 30 minutes without using any water, and read it again. If the reading has moved, water is passing through the meter somewhere on your side of the system, which points to a leak rather than an isolated fitting.
Can pipes just make noise without an actual leak?
Yes. Air in the pipework, a water hammer effect from a closing valve, or normal expansion and contraction as pipes heat and cool can all create sounds that resemble running water. These tend to be brief or triggered by something specific, such as the heating firing up, rather than a steady continuous sound.
How does acoustic leak detection find the source of the sound?
Acoustic sensors and correlators listen for the distinct sound signature water makes as it escapes a pressurised pipe, then compare the timing of that sound at two points along the pipe run to calculate the leak’s position. It is a non-invasive method, so the source can usually be pinpointed before anything is dug up or opened.
What should I do while I wait for someone to check it?
If you can hear water clearly and your meter confirms movement with everything off, it is sensible to know where your stopcock is in case you need to isolate the supply. Otherwise, avoid opening up walls or floors yourself, and keep a note of when the sound started and whether it varies, as that detail helps narrow down the cause.
Will home insurance cover the cost of tracing the sound to a leak?
Many buildings insurance policies include trace and access cover, which price-comparison service Confused.com notes pays to find the leak, gain access, and make good the damage caused during the search, commonly up to around £5,000, though it typically excludes the cost of the pipe repair itself. Always check your own policy wording.
Still hearing water with everything off? Let’s find the source
If your meter confirms a leak but you can’t see or place it, we’ll pinpoint the source across Cornwall & Devon using acoustic listening equipment, with minimal disruption to your home.
Call Dickie on 07822 025 911 No Find, No Fee on residential leak detection (subject to terms)