How to Find a Water Leak

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Written by Eric

Last Updated: 11/12/2020

How to Find a Water Leak

Noticing warping floor? High water bill? Sudden foul smell? Cracking floors or wall? Damp carpet? All these could be signs of a water leak in your home. Don’t let this make you assume detecting a water leak is obvious though; it can be quite tough if it is hidden and when you don’t know where exactly to check. What’s worse is that whether small or big, a water leak is hazardous to both your home and your family’s health the reason you have to find it and fix it as soon as it occurs. Not to worry though, because below is a guide that will help you to identify a water leak and therefore, ensure you detect it in good time.Moreover, it is simple enough so you can do it by yourself and save the cost of a plumber.

Hot Water Tank

While your hot water tank may not be one of the things in your house you would expect to find leaking, it can happen though. A leak on your water heater will start small then increase over time causing serious damage. Therefore, you must understand how to properly identify a water leak and fix it in good time. So, how do you find a water leak in your water heater?

First, ensure that you are safe from any danger by turning off the source of power for the hot water tank. This will be different depending on whether you own a gas water heater or an electric one. Let’s look at each;

  • Electric water heater

Find the breaker in your home’s electrical panel and flip it to cut the power supply to the heater. You can also turn off the main electricity switch in case you cannot identify the above breaker.

  • Gas water heater

Same as electric water heaters, you will have to cut the supply of gas to the water heater. You can do this by either turning off the valve on the gas line or by setting it on pilot mode.

The second thing you will need to do is to ensure cold water is not being supplied into the hot water tank. This can easily be done by turning off the valve that controls the water supply or the main valve for your home.

After the above, you are now ready to detect where the leak is coming from. But where do you start checking? Below are the areas that are most likely to be leaking;

  • The pressure relief valve

Moistness on the pipe at the side of the water tank could mean that the pressure relief valve is the reason for the leak. This could be because it is either defective or could be due to pressure build-up in the hot water tank. The leak will be easy to fix if a faulty pressure relief valve is its cause since all you have to do is replace the valve.

The other cause of the water leak could be excess pressure in the water tank. The water pressure of your tank increases as temperature increases and needs to be released since it is unsafe. The valve, which is usually located on the side of the water tank will open to release the excess pressure once it reaches unsafe levels. Once the valve opens, the attached pipe lets water through it. While this means the valve is functioning well, you will have to detect and fix the cause of the increased pressure.

  • Pipe connectors

A loose connection on the hot water pipe and the cold water inlet could also be the cause of the water leak. All these are located on the top of the hot water tank so it shouldn’t be hard for you to identify them. You can quickly fix this by tightening the loose fittings.

  • Drain valve

As you may already know, your hot water tank needs to be taken care of frequently to ensure it functions properly. The drain valve is the device that you use to let water out of the tank during maintenance. The faucet could lead to a water leak if it either loose or faulty. A malfunctioned valve will need you to replace it while a loose one will need tightening.

  • Water heater tank

Water heaters will serve you for long years, but they also wear eventually. A water leak from the bottom of your water tank could mean the presence of a hole. Unfortunately, leakages caused by old water heaters means it’s time to call a professional plumber to replace your hot water tank.

It is, however, good to know that regular maintenance and care of your water heater will help manage sediment build-up to ensure the tank offers you extended service.


Toilets are not new to causing water leaks in households. Toilet leaks can be easy or hard to detect depending on how silent they are. You may be lucky to hear the sound of running water or water hissing or dripping which will make it easy for you to identify the water leak. So, how do you check for toilet leaks?

  • Using food color

Take out the top of your toilet tank and flush the toilet then wait for the water to fill back to its usual level

Get a dark-colored food coloring and drop about five drops into the toilet tank. You may also use a dye tablet if you don’t have food coloring

Without flushing, place back the toilet tank lid and wait for about 20 minutes

If the watercolor in your toilet bowl has changed, there is a water leak. If not, then there is no leak.

It will be useful to eliminate the possibility of toilet leaks, therefore, ensure you perform the above check on all the toilets in your house

  • Water level

Take off the lid from your toilet tank and check whether the water is above the overflow pipe. This could mean there is a water leak since the float is supposed to alert the inlet valve when to stop water from flowing into the tank. You can check the inlet tap by lifting the float. If the water stops, it means the float is the cause of the leak, and you will need to replace it.

  • Flapper

In case the water level does not go above the overflow pipe, but water is still being let into the toilet tank, the problem could be with the flapper. To detect this, you will have to turn off the water supply close to your toilet to ensure water does not flow into the toilet tank. Give it about 15 minutes then check whether the water level has gone down. If the water level has decreased, it means the flapper has let water into the water bowl due to a leak or its chain may be too tight.

Water Meter

This could be the best way of detecting whether there is a leak on the plumbing line. First, ensure that no one is using water both inside and outside the house. Locate the meter, remove its lid to check the dial at its top. The dial will be moving if you have a leak. You can also take your meter reading, ensure no one uses water in your home, then come for another reading after about an hour. A difference in the readings means you have a leak.

This is not the end though; you will also have to figure out whether the leak is in or out of your house;

Cut the water supply to your house by turning off the main valve. Repeat the above steps. If the leak is inside your house, there will be no difference in the meter readings or the dial will not be moving. Otherwise, the leak is outside the house.

If the leak is out of the house, you can locate its exact spot by checking the area between the meter and the main valve for muddy regions or healthier grass than on other parts. Call a professional plumber in case you can’t locate the leak by yourself.

Water Bib

You can determine a leak on your hose bib in two ways;

  • Using a screwdriver

Place the metal tip of the screwdriver on the metal section of the hose bib. A long screwdriver will give you ample space to work with hence the best to use. Place your thumb knuckle at the top of the screwdriver then put the thumb close to your ears and listen for any sound. Repeat the process for all the hose bibs while noting any increase in the sound since the louder it is, the closer the leak is.

You can also use the same method to detect leaks in units inside the house such as the sink faucets, showers, and the water heater.

  • Using your thumb

Place your thumb or your whole hand over the water faucet and turn on the water tap. In the absence of a water leak, you will find it hard to hold the water back due to strong water pressure. Otherwise, you will be able to keep water from flowing out which will mean there is a leak somewhere along the water pipe.

Under concrete

Wear may cause water pipes under your house to start leaking. There are various ways to detect leakages underneath your house;

  • Water pools on your floor

In case of water leakage, the water builds up under the concrete which will then be released to the top of the floor. You can notice this through water pools, dampness on your carpet or your wooden floor will start warping.

  • Warm spots on your floor

While it may sound crazy, your feet may help you detect water leaks beneath your floor. Take off your shoes and feel for warm spots on your tile or wooden floors caused by hot water pipe leakage.

  • Mold and mildew

Mold and mildew thrive in damp areas. Slab leaks will cause water to sit for a long time under the concrete which will cause mold build-up. Sudden stale smell in your house could mean there are mold and mildew patches under your carpet or other places the water will spread to.

Sewer Pipes

While we are used to leakages from fresh water pipes, sewer pipes may leak too. You can detect this through cracks on your foundation or your floor warping. You should also watch out for bent or disjointed walls or molds and mildew.

Irrigation system

Your home’s irrigation system stays outside most of the time hence prone to damage due to the harshness it takes. Here is how to find a water leak in your irrigation system;

  • Dry patches

Your irrigation system is supposed to water all areas of your lawn. Leaks on the system will reduce the water supply causing parts of your lawn to dry since they do not receive enough water.

  • Soggy spots

Your irrigation system is designed to distribute water evenly and just enough to keep the grass on your lawn growing. This means excess water on the floor could be a sign the system is leaking.

Swimming pool

A reduction in the level of water in your swimming pool could be because of evaporation or splashes, but it could also be from water leaking. Here is how you can find out;

  • Using water level

Mark the water level in the pool then check it after 24 hours. A drop of more than a quarter of the water in a day means you have a leak.

  • Using a water bucket

Fill a bucket with water from your pool and place it on a pool step. Ensure the level of water inside the bucket levels with the pool water outside and mark both the inside and outside of the bucket. Check after 24 hours. A significant difference in water level means you have a leak. A slight drop is due to evaporation.

Other Ways to Find a Water Leak

  • Reduction in water pressure

If you notice the flow of water is not strong enough to support daily chores in your household, it could mean you have a water leak. This leads to a fall in the water pressure reducing the flow of water to your sinks, bathtub or shower heads. You can detect the leak by turning off all other fixtures then inspect each faucet on its own.

  • Increase in water bill

For households used to paying the same amount for their water and sewer bill, a significant shoot on the price should be a cause for concern. You should also suspect a water leak if your water bill keeps increasing each month while the consumption has not changed. However, note that this only lets you know there is a water leak but won’t tell you where exactly it is.


Water leaks are easy to fix and save you a lot of money if you identify them early enough. Ignoring them will not only cause damage to various areas in your home but also lead to expensive water bills. A leak can occur almost anywhere in your house, and it can be just a drip or huge, but both will damage your walls, distort your floors, and lead to foul smell due to mold and mildew.

All in all, whether small or huge, fixing it by yourself or calling a plumber, do not overlook that leak. This will ensure your household receives water flow with sufficient pressure to allow your family to carry on with various chores within the house concurrently. Our guide on how to find water leak will help you detect the leaking spots like a pro. Whether on your swimming pool, the garden, toilet, water heater or kitchen faucet, we ensure you will never have to worry.


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