Water Leaks

Press Enter to show all options, press Tab go to next option

A helpful guide for locating indoor and outdoor water leaks.

Print this Water Leak Detection Kit.

Nixa Utilities water verticalA slow drip can waste as much as 20 gallons of water each day. With that much water (AND MONEY!) going down the drain, it's important to get leaks fixed as soon as possible. Only one tiny hole in your home's water system can waste more than 4,000 gallons of fresh water each month - enough water to take a shower every day for a year!

Consider how important water is for our families, pets, and environment, and you see that even tiny holes and leaks deserve immediate attention.

That's why we developed this simple water leak detection guide. It's designed to help you find and repair water leaks - even the tiny ones.

Shut-Off Valves:

Your main shut-off valve controls all of the water coming into your house. Everyone in your home should know the location of this valve and how to turn it off. In case of an emergency (such as a burst pipe), fast action could prevent costly damage from flooding.

If you don't know where this valve is located, it's important that you find out. Normally, it's near the water meter. If your meter is outside the house, find the place where the water service line enters the building. The shut-off valve is likely to be close by. Common locations are in the basement, under the kitchen sink, near the meter box, or at the pressure regulator (if required.)

After finding the valve, turn it to make sure it isn't stuck. Water valves are generally closed by turning the handle clockwise. If a valve does not turn easily, do not force it or it may break. Rather, you may want to have the valve repaired so that it will work when you need it.

When opening the valve to turn the water back on, open it fully, then close it just a quarter of a turn to make closing the valve easier the next time. You should also check every water fixture shut-off valve periodically, and consider operating the main and individual valves annually.

Now you're ready to begin!

Getting Ready:

Use the checklists below to help direct your search for some fairly common - and a few not-so-common - water leaks.

How can you be sure your inspection will be as thorough as possible? The checklists cover three areas: common indoor leaks, not-so-common indoor leaks, and outdoor leaks. If you investigate the leak possibilities in the order shown, you'll uncover the greatest potential for savings in the first few places you look.

It's a good idea to have the following items with you as you begin your work:

  • Flashlight
  • Food coloring

The Leaky Toilet:

Accounting for more than 95% of all water waste, toilet leaks are caused by worn or damaged parts in the toilet flush tank.

(Toilet flushes account for about 100 gallons of the water use in your house each day. That's about 40 percent of the average household use.)

Some of these leaks will empty directly into the sewer line without leaving any clues. Even so, you can check for these leaks. Common causes include:

Float Arm Problems:

Remove the lid from the top of the flush tank. See if the overflow pipe and the plunger ball are working properly. Do this by flushing the toilet, watching the tank mechanism and listening. You should hear the water flow shut off.

If the water does not shut off, check the water level. If it has risen above the overflow pipe, gently bend the float arm down and flush again.

You may need to replace the plunger ball if the water level is about one inch below the top of the overflow pipe and you still hear water flowing.

A Tiny Pinhole:

A pinhole opening below the overflow pipe's water line could produce an invisible leak. Check for this by shining a flashlight down into the overflow pipe. If you see running water, you have a leak that should be repaired.

Water in the overflow pipe could also be caused by a pinhole in the float or a worn washer on the inlet line.

A Defective Plunger Ball or Flapper Valve:

This is often a silent leak which causes the tank to continually drain and refill. Check for a worn or improperly seated plunger ball or flapper valve (depending on the model of toilet) by dropping a few drops of food coloring into the toilet tank. Do not flush. If a leak exists, the dye-colored water will seep into the bowl in about five minutes. If it does, the plunger ball or flapper valve may need to be replaced or realigned.

The Leaky Faucet:

Check every faucet, even in out-of-the-way places such as the garage, basement, or closet.

A dripping faucet

A slow drip can waste as much as 20 gallons of water each day. A mere 1/16-inch leak wastes 100 gallons of water each day. With that much water - and money - going down the drain, it's important to get leaky faucets fixed as soon as possible.

If you notice that a faucet is dripping, first try closing it tightly. If it continues to drip, the most likely cause is a worn or wrong-size seat washer (also called a stem washer). With just a little effort, you may be able to replace the washer yourself. You may need an adjustable wrench, a standard-blade screwdriver, and a Phillips screwdriver for older plumbing fixtures. It may be more economical to rebuild or replace the faucet if it is washerless.

Changing a washer

Before you start, turn off the water supply to the faucet by closing the fixture's shut-off valve. Most kitchen and bathroom faucets have shut-off valves under the sink. Turn the valve clock-wise until it's tight. This shuts off the water to the sink only, and does not affect the water service for any other part of the house.

Be certain that the replacement washer is the same size as the worn one (if the worn washer was the correct size). If you need help, bring the worn washer to your plumbing supply or hardware store, and the store representative can help you match it with a new one.

Other Things to Check Indoors:

Bathtubs & Showers:

Check the spout and shower head for dripping water. New washers may be needed on the faucet handles. You may be able to do this repair yourself by unscrewing the faucet and replacing the washer with one of the same size. Before doing this repair, close your home's main shut-off valve.


Water accumulated on the floor near the unit could be a sign of a leak. You may want to call your dishwasher repair service.

Refrigerator Ice-Making Unit:

A leak in the ice-making unit will cause excessive ice accumulation in the freezer and may also produce small puddles of water under the refrigerator.

Water Heater Tank:

The pressure valve release could be stuck. This valve is most often found near the top of the tank, and is usually a large brass fitting threaded into the tank. If it's not working properly, water will be leaking from it, dripping down the side of the tank and accumulating on the floor.

Water Softener:

If you have a water softener, it could be wasting water if it is not recycling properly. The cycling process, regulated by a timer, often occurs between 2am and 4am. You're likely to have a problem in this unit if you constantly hear the sound of running water.

Washing Machine:

If you see water on the floor near the machine, it could mean a leak. You may want to call your washing machine repair service.


Water accumulated beneath the unit could be a sign of a leak. If the overflow discharge is piped into a sewer or drainage line, you may not find any visual signs of a leak. Listen for running water. If it's continuous, the float valve could be stuck.

Fire Suppression Systems:

Many newer homes and businesses have fire suppression systems. If so, check to make sure that the sprinkler heads are tight and not leaking.


Listen for the sound of running water. If it is continuous and does not stop and start periodically, your boiler system may have a leak.

Outdoor Water Leaks:

When checking for water leaks, many people forget that water faucets and equipment exist outside as well as inside the home. Here are four areas you should not overlook.

Water Faucets:

Each faucet should be checked for leaks. Make sure faucets are closed when not in use. If you find a leaky faucet, change the washer (after closing the shut-off valve).

Your home may have inside shut-off valves for the outdoor faucets. In colder climates, during the winter, these inside shut-off valves should be closed to prevent freeze-ups. Be sure to open the outside faucet after you have shut the inside valve so that any water still in the pipes will drain out. These shut-off valves are usually in your basement. One shut-off valve may control all the outdoor faucets.

Automatic Lawn-Sprinkling System:

Soft spots on your lawn may indicate a leak that is being absorbed into the ground.

Swimming Pool:

The pool system's automatic shut-off valve could be malfunctioning, causing a continuous cycle of water to be pumped in and then drained out. If the water level stays higher than normal, or the pool overflows when people are using it, your automatic shut-off valve may need some attention.

Service Connecting Line:

If you find a soft, wet spot on your lawn or hear running water outside your house, you may have a leak in the service line to your house. Water soaks into the ground, causing the soft spots. Close the main shut-off valve. If the sound of running water continues, the outside service could be leaking.