How To Find A Water Leak


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In this article we're going to show you how to find a water leak. 

According to the EPA, 10% of homes have a water leak that wastes up to 90 gallons of water per day. That's a lot of wasted water and a lot of wasted money. Even if you have a dripping faucet, that can equal hundreds of gallons of water per year.

And chances are (if you are like most of us) that you haven't checked for water leaks recently.

So we're going to guide you step by step in finding water leaks in your home.

Step 1: Determine If You Have A Water Leak

Before you can narrow down where a water leak is coming from, you need to determine if you even have a water leak. The good news is that it is fairly easy to determine in just a few steps. Below are the steps you'll want to follow.

Find Your Water Meter

First, you'll need to find your water meter. At my house, the water meter is located by the street. It is housed inside of a box in the ground. Your water meter has a gauge attached to it that will tell you how much water you have used. 

My water meter box was filled with dirt and sand. So I ended up bringing a small garden shovel to remove the dirt so I could actually see the meter.

Record Your Beginning Water Meter Reading

You'll want to make sure that no one uses any water while you are looking for leaks. Turn off your ice maker, fill up water bottles and use the bathroom so that you won't need to use the water for the next 2 to 3 hours.

Record your water meter reading at the beginning of the process. 

Wait For 2-3 Hours

Once you make your initial reading, you will wait for 2 to 3 hours. During this time it's important that you don't use the water in your house.

record your meter reading again

In theory, if you have not used any water for the past 2 to 3 hours, then your water meter reading should be exactly the same.

If you have a small leak, you will notice the gauge has moved a little. If you have a larger leak, you'll notice it has moved quite a bit. Record your water meter reading and see if it is the same or different. 

If you find that the water meter reading has changed, then it's time to try to narrow down where the leak is coming from. 

Step 2: Find The Water Leak

For the remainder of this post, we will assume you have a water leak. If you don't have a leak, then great! But be sure to check again at least once a year. Things break and deteriorate over time, so it's important to check for leaks on a regular basis. 

However, if you find that you do have a water leak, there are a few steps you can take to determine where the leak is located. In the rest of this article we'll cover where you should look for water leaks in your home.

Main Water Line Leak Detection

The first place you should check for leaks is between the water meter and the main cutoff valve for your house. Find your main shutoff valve and turn it off. Mine was located near the front door of my home. Once you turn the main cutoff valve to the off position, no water should be running in your home.

Once you have turned off the main water valve you will take another meter reading. Then you'll wait another 2-3 hours and read your water meter again. If the water meter reading shows water being used, then you have a leak in your main water line between your meter and your cutoff valve.

Main water line leak symptoms include wet spots in your yard, soggy ground or even discolored areas in the yard. However, not every main water line leak is easy to detect. You may need to hire a leak detection specialist to help you pinpoint the area that needs to be fixed. 

A leak detection company will use special leak detectors and methods to determine the location of your underground water leak. Pro-Tech can recommend a reputable leak detection company for you and assist you in the event that your main water line needs to be repaired.

Visually Inspect Your Home For Water Leaks

If you've followed the steps above and you have determine that your water leak is not between the water meter and your main cutoff valve, then this means the water leaks is somewhere else inside of your home. Turn you main cutoff value to the "on" position so that you have water running inside of your home again. Next, spend some time visually checking some of the most common places for water leaks.

Toilet Leak Detection

It is very common to have a leaking toilet, so the first place you'll want to check is your bathrooms. Once you determine which part of your toilet is leaking, you can figure out what to do about it.

First check for a toilet water supply line leak. The supply line connects the plumbing inside of your wall to your toilet. Check both ends of the supply line for leaking water.

Next, check to see if your toilet is leaking around the base. If your toilet is leaking around the base, this is a sign that your wax toilet ring may need to be replaced.

There is a wax toilet ring on the bottom of your toilet that creates a waterproof seal so that toilet water doesn't leak when flushed. However, this wax toilet ring can compress over time causing the seal to break. While you can purchases toilet wax ring replacement kits at the store, we advise having a professional plumber replace the toilet ring (it's not easy).

Another problem that causes leaking around the base of your toilet is problems with the toilet flange. The toilet flange is the drain in your floor that the toilet empties into. If the toilet flange is not lined up properly with the floor and the base of the toilet, it can cause toilet leaking over time. If your toilet flange is too high or too low, there are toilet flange extenders that can help correct the problem. You may also need to replace your toilet flange if you have an old house and it has deteriorated beyond the point of repair. Again, this is probably not a do-it-yourself project for most people.

If you open up the tank on your toilet, you will see the toilet fill valve and the toilet flapper. The toilet flapper valve is the cone-shaped piece of rubber that opens when you flush the toilet and closes after the tank has been emptied. The flapper can become worn out over time and can slowly leak water into the toilet bowl. This is hard to detect because you won't see water leaking onto your floor. It will simply leak into the bowl. However, if your toilet keeps running at random times during the day, the toilet flapper is probably to blame.

The tank also contains the toilet fill valve. This is the mechanism that adds more water into the tank after you flush the toilet. It is a good idea to replace your toilet flush valve at the same time as your replace your toilet flapper. A toilet repair kit contains the parts needed to fix this and can probably be done by the average DIY'er.

To determine if your tank is leaking water into your toilet bowl, you can perform a toilet dye test. To perform a toilet dye test, you can place a few drops of food coloring in your toilet tank (we recommend a light color). Wait for a few minutes and look for food coloring seeping into the toilet bowl. If this happens, then your toilet is leaking water. Be sure to flush the food coloring out of your bowl after a few minutes to avoid staining the toilet. 

There are a few final things to check on a toilet. 

Your toilet handle connects to the flapper with a little chain. The toilet chain can get caught and prevent the flapper from closing. This causes water to leak. Lastly, your toilet also has an overflow pipe that prevents the tank from filling up with too much water and spilling on the floor. If your toilet fill valve is not properly calibrated, it will put too much water in the tank and cause your toilet to run non-stop. 

Now that you've checked your toilets, let's check under your sinks.

Leaky Faucet

It is fairly easy to spot a leaky faucet because you'll hear and see water dripping from it. We won't go into how to fix a leaky faucet because this article is about how to find a water leak. But depending on the type of faucet that you have, you'll need to replace the sink cartridge. This involves removing the handles from the sink, replacing the internal parts and putting it back together.

Another place to check is the shut off valves under the sink. Check the hoses and make sure there is no dripping water on any of the connections. If you notice water, you will need to replace the gaskets in the fittings or replace the water lines altogether.

If you look under the sink you may also find traces of water dripping from the under sink plumbing. This could lead to damage in your cabinets or flooring under the sink. Make sure all the drain pipes under your sink are connected properly. This is also a good time to clean the p-traps under your sinks. If they appear damaged, you should replace the piping to avoid additional damage in the future.

Water Heater Leak

Is your water heater leaking? This is the next place you want to check. A hot water heater leaking can eventually lead to expensive damage. 

A water heater has several parts that you should check for water leaks. When checking the water heater for leaks, turn off the power to your water heater by locating your circuit breaker and disconnecting power to the water heater. Leave the cold water supply turned on while you check for leaks.

Visually inspect the entire water heater for leaks. Run your hands over all the connections and feel for water. 

All water heaters have a pressure relief valve that is designed to alleviate pressure buildup if the water inside of your tank gets too hot. You may occasionally see water dripping from the pressure relief valve, but this is the intended purpose and should not be a cause of alarm as long as it's not excessive. The pressure relief valve is located on top of the water heater. So if you notice water leaking on top of water heater, check the pressure relief valve. Under normal conditions, it should not regularly leak water. If it is leaking constantly, then you can replace the relief valve.

The cold water supply may also be located on top of the water heater. Examine the connections around the cold water supply for leaks. If you notice water dripping from the connections, you can attempt to tighten the connections. If that doesn't work, then a plumber can replace the connections.

On the bottom of your water heater is a water heater drain valve. The water heater drain valve is used to flush your water heater. The drain valve can corrode over time and begin to leak. So check this part of your water heater as well.

Lastly, look at the hot water outlet for leaking water. The cold water inlet and hot water outlet have connections that can leak over time. 

Your tank may be leaking internally. If the water tank is over 10 years old, you should consider replacing your water heater tank. However, if your water heater is relatively new, then you should consider repairing your water heater.

Water Leaking Inside Wall

So far, we've talked about finding leaks in your fixtures and appliances. However, you could have a leak inside the wall. These kinds of leaks can be much harder to detect. So how do you find water leaking in the wall? You'll have to do a little investigating. These are the signs you should look for: 

  • Discoloration of the paint on the wall or ceiling.
  • Bubbling of paint due to water under the surface.
  • Sagging or drooping drywall.
  • Presence of mold or mildew on the wall or ceiling.
  • A musty odor in your room.

If you see or smell any of the symptoms above, then these are signs of a water leak inside your wall.

Water Leaking Underground

Water leaking underground is probably the most difficult type of leak to detect and may require special tools to locate. If you suspect your water leak is located underground, you can look soggy or wet spots in your yard. If you have checked all the most common places for leaks in your home, then most likely the leak is occurring under the ground. 

Signs of Underground Water Leak

  • Look for unusually wet or soggy areas in your yard.
  • Sudden decrease in water pressure.
  • Dirt or rust in your water.
  • Sudden increase in water bill.


Hopefully you are able to detect a leak using by checking the areas described above. If you have tried locating the leak and you still aren't having success, then you can contact Pro-Tech. We have a team of Orlando plumbers with specialized tools and years of experience to help you locate and repair water leaks.

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