Why Do You Hear Water Running with Everything Turned Off?

leaking pipe
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  • Beginner

The easiest water leaks to spot are the ones where the leak leaves you with a water spill on the floor, inside a vanity, on a countertop, or possibly on a ceiling tile or wallboard if it originates from the floor above.

Those are the most common leaks but being so obvious, they’re usually readily looked after and fixed. The hidden leaks are the worst kind and will usually create more headaches to locate and will often result in more serious structural damage if they’re let go for some time.

Leaks from Water under Pressure

Water leaks originating from the supply side of the plumbing anywhere between the water main and a water tap, valve, or shut-off valve has water under pressure pushing through a break, a split, a pinhole even to cause a constant drip, dribble, or a spray of water coming out requiring you to replace a component, repair or replace a pipe.

You can’t always see the signs of a leaking water pipe, but coming from water under pressure, the leak causes friction that often generates a hissing, whistling, or gurgling noise and creates a distinct undeniable giveaway.

That noise will also be your clue as to determine where the break originates, especially if it’s hidden behind a wall, and will let you know when you shut off the valve controlling that particular branch of your main supply line.

Leaks from Drain Pipes, Plumbing, and Fittings

plumber fixing leaking pipes

Another type of water leak comes from bad, worn, or damaged pipes or seals on the drain side of your plumbing.

We’re talking here about toilet seals on the floor flange, leaking traps under sinks, corroded drain components, and defective seals on drain fittings.

A leaking toilet seal where the water silently creeps between the flooring and the subfloor, or a broken drain under a sink or vanity is the kind of leak that can go silently unnoticed for a long time, creating situations for mildew, mold, and rot formation to occur after some time.

If left unchecked for months or even years, it could do some serious damage to the structural aspect of your home and eventually become a costly repair.

pipes with water damage in wall

What Can Result from Water Leaks?

Even for a seemingly armless small leak, mold formation, damage to the floor, floor covering, walls, and even structural issues can occur within 24 hours.

Water spreads quickly and absorbs into floors, walls, and soft furnishings, and the cost to fix your home could quickly become hefty.

Water seeping through floors and ceilings can also cause damage to insulation and wooden beams and framing. Within the first week, the mold can spread rapidly, the damage to wood surfaces and walls can greatly intensify, and you will also witness corrosion of affected metal parts and surfaces.

If left unchecked past the first week, further increased risks for significant spreads of mold and increased structural damages will quickly build up, with the extent of the problem more significant than it seems.

Water damage repairs should be started within 24 to 48 hours to minimize damages effectively.

How to Detect a Water Leak on the House Water Supply Line

mysterious sound

We mentioned earlier how the water leaking under pressure would probably create a sound from the friction while seeping out or flowing through a fissure or a break along the main water supply line.

It is possible to hear such sounds wherever they originate from along the water lines, being inside the structure as well as outside the house to the city’s water main.

It may not be a loud sound, but if everything is really quiet inside the house, especially at night when all is at its most silent, you’ll have a better chance to hear it.

This will make it possible to follow the sound to a more specific area inside the house.

The water distribution system is usually laid out into several branches, all of them originating from the main supply line.

You should usually find shut-off valves along each of those branches before they lead to their intended purposes, such as the kitchen sink, ice maker, dishwasher, bathroom sink, shower, bathtub, toilet tank, hot water heater, water softener, outside taps, etc.

But don’t be deceived, though, as metal waterlines make an excellent conductor for noise, a leak underground near the water main can easily resonate throughout the house and be near impossible to pinpoint.

A branch from the water distribution system is usually set up for distributing water to several household devices, each one equipped with its own shut-off valve and the whole branch also fitted with its own separate shut-off valve.

Step 1 - Listen

As described above, with the house really quiet and silent, listen carefully to locate by sound the general area of the leakage.

Step 2 - Test Valve

Find the closest water line and follow it back to the branch’s shut-off valve. Shut the valve off, then listen carefully to make sure the noise has stopped, which would indicate that you’ve found the right valve.

Step 3 - Identify Valve

If the noise persists, however, keep shutting off branches that could lead to that general area until the noise finally stops.

Step 4 - Shut Off Other Valves

Once you finally get to the right branch of the system, shut off all the other branches going throughout the house.

Step 5 - Check Devices

Turn the leaky line back on and check every device that you figure is connected to that specific branch—this will tell which water lines should be checked for leaks.

At this point, tracking back the line might require you to remove ceiling tiles from the basement ceilings so that the water lines can be followed to the leak. In some locations, that may prove to be impossible by the fact that the pipes are inside walls and fixed ceilings.

Before tearing down walls and ceilings, however, you should inspect the area for some obvious physical anomalies on the drywall, floors, ceilings, and painted finishes.

Look and listen carefully for the following clues:


Water stains and discolorations showing up yellowish and brownish on walls, and ceilings, indicate water leaking from behind drywall and soaking through to the front.


Some leaks can be silent as the water travels along a wall stud, crawling along the inside of a ceiling tile, or flowing along the wallboard’s inside surface. As it soaks up the water, you can check for swelling, mainly around the screw heads and the joints forcing the tape away.

Paint Bubbles

Check the painted surfaces and the wallpaper for ballooning or bulging surfaces from the top layer separating from the wet wallboard.


The somewhat regular dripping sound from water drops as they hit a surface can also give a definite clue as to the general location where the leak is occurring.


A constant leak will eventually create the perfect humid environment for mold to form and grow often behind a wall or underneath the flooring and easily noticeable by its musty smell.

Water Supply Line Leaks

plumber fixing pipes with wrench

Water leaks don’t always originate inside the house.

The infrastructure of your town might have outlasted its expectancy, and its degradation in certain areas might be starting to show some extensive wear and start failing.

A definite telltale is your town’s Water Department making more frequent repairs on their lines in your immediate neighborhood.

A water leak between the water main and the house is more common nowadays with the aging infrastructures, and such leaks can lead the water back into the house.

Such leaks, however, can also cause dirt and other contaminants to infiltrate your water supply line, making it hazardous for consumption and causing some discoloration of your drinking water.

These types of leaks, even if the pipes are buried deep underground, can sometimes be heard inside the house, making it a bit more tricky to follow its source.

Branching off from the Utility’s water main, your home’s water supply line or pipeline is divided into the Public Water Service Line and the Private Water Service Line with the demarcation at the property line.

The water pipeline also has several devices attached to it, starting with the shut-off valve between the water main and the demarcation point, a water meter anywhere between the curb’s shut-off or stop valve and inside the basement, and another shut-off valve on the pipeline’s side of the water supply line.

The pipeline or water supply line is usually buried deeply underground—at least 3 feet (1 meter) or deeper, making the leaks outside the house more difficult to detect.

There are, however, a few signs that can help you determine that particular source of leakage:

Water Sounds

If you hear water running even with all the different branches shut off, then follow the water line bach to the first shut-off valve after the line comes through into the basement and shut that valve off as well, but still hear water running, you can pretty well deduct that the leak is somewhere between the basement and the utility’s water main.

You will then need to get the utility to come over and determine if the problem lies with them or if it’s on your side of the property line and therefore your responsibility.

Basement Water

If you have water infiltration into the basement where the supply line enters the house, it is probably due to the water flowing along the pipeline following that easier path right up to the house.

You can look for this by following the water pipe all the way back to where it penetrates the basement floor or the wall.

That’s where you’ll find your clue in a large water puddle near the entry point, on the floor.

Since this is the same problem as above, here again, you need the water utility to determine whose responsibility it is to do the repairs.

Wet Soil

If you find the soil above the area where the pipeline is buried damp or wet, it can also be an indication that you have a severe leak in the water supply line, bad enough for the water to seep up to the ground surface.

The only difference, in this case, is that the wet ground is probably on your property and not in the street, making it probably your responsibility to repair.

If the sidewalk over the public water service line seems to be abnormally wet, however, the leak is probably under the water utility’s responsibility.

But either way, your water utility should be promptly notified since they have to shut off the curb stop before any repair is done, which should happen without much delay, since your drinking and cooking water source is now seriously contaminated.

Any time that you suspect the leak to be somewhere along the pipeline, prior to the shut-off valve in the basement, you must contact the water utility and request an assessment of the problem before attempting any repairs on the water supply line.

They can determine by closing the curb stop if the problem lies within the public water service line or the private water service line.

As mentioned briefly earlier, if the leak stops when the shut-off is closed, the break in the line is on the private service line’s side, which is your responsibility as the homeowner.

If the curb shut-off doesn’t stop the leak, however, it will usually be the water utility’s responsibility to do the repairs on the line.

It should also be noted, however, that if the utility determines that the leak is the responsibility of the homeowner, the repairs should never be attempted by the homeowner himself, but rather by hiring a professional plumber.

The homeowner should limit his expertise inside the house, past the water meter, which is the water utility’s property.

With these tips and acquired knowledge, you can now follow the sound of that running water and find out where it’s from, but for more info on closely related subjects, you can follow these links and find more on the underground water line leak, what to do with a damaged water control valve, or possibly look at a different approach.