The two most common causes of a toilet leak are the flapper or fill valve. To check for these leaks, lift the tank lid and look at the back wall of the toilet tank. You will see a water line that marks the level at which water fills the tank.
For the most precise leak detection, plumbers use video pipe inspection equipment. These are small cameras mounted on long flexible fiber optic cables. Plumbers can insert these in faucets and other plumbing outlets to detect leaks.
Identifying a Silent Toilet Leak
First, try lifting the toilet seat and see if you notice water trickling down the sides of the bowl or moisture accumulating around the toilet base. If you do, there may be a leak. Flushing the toilet is another way to tell.
To test for a leak, simply open the lid on the toilet tank and add a few drops of food coloring. Don't flush the toilet -- instead, wait an hour or two without using the toilet at all. Afterward, check the water in the bowl. If the food coloring has seeped into the bowl, you know you have a leak.
The most common cause of this issue is a faulty flapper valve. The rubber seal at the bottom of the tank controls the water flow into the bowl. If it's not sealing properly, water will leak through and cause your toilet to constantly fill and drain.
An undetected toilet leak could waste as much as 5 gallons of water per minute. The most common toilet leak is caused by a deteriorated flush valve (flapper) at the bottom of the toilet tank. If the flapper does not seat properly, water will leak into the toilet bowl. Often this leak will occur without being heard.
This may be due to a faulty fill valve, flapper, or flush valve that is not sealing properly. Sometimes, you may hear a faint dripping sound in the toilet bowl even when the toilet is not in use. This can indicate a slow leak in the tank that is causing water to drip into the bowl.
To see if the flapper is leaking, here's a simple test: Put a few drops of food coloring in the tank as a toilet leak detector. Wait for 25 minutes. If the color spreads into the toilet bowl, there's a leak.
Thermal Imaging Cameras
They detect temperature variations that indicate the presence of leaks, making this technology particularly useful for finding hidden leaks. Endoscopic cameras also provide valuable visual information, allowing for the inspection of pipes and fittings.
Water leak detectors can detect water pooling, and some can also detect water dripping or even humidity rising. Premium water leak detectors monitor the flow of water in your pipes. All connect to a hub or directly to your Wi-Fi network to send alerts when they detect a problem.
Causes include a leaky flapper, too much water in the tank, or refill tube issues. Leaky Toilet: Expect to pay $100–$600 for leaky toilet repairs. Leaks happen where the toilet meets the floor, at the water supply valve, and between the bowl and tank. Clogged Toilet: Repairing a toilet clog costs $85–$600.
The only-when-flushed toilet leak could be caused by loose mounting bolts or a worn-out wax gasket while the all-the-time leak could be caused by a loose water supply line connection, a problematic water shutoff valve, or a faulty seal between the toilet tank and its base.
A continuously running toilet can waste up to 200 gallons a day or more depending on the volume flow down the drain. This can cause a terrible increase to a family's typical water use, so fix toilet leaks as soon as possible. Some leaks are easy to find, such as a dripping faucet or running toilet.
One cause of silent toilet leaks is a faulty flapper valve as it controls the water as it flows from the tank into the bowl of your toilet. If it becomes worn or damaged, it can allow water to continuously leak into the bowl without making any noise.
Replace Toilet Flapper or Gasket
To get to the toilet gasket, remove the the two bolts that attach the toilet tank to the toilet bowl. You will need a screwdriver and adjustable wrench. Each bolt will have a rubber gasket or washer that helps prevent leaks. Replace these gaskets with new ones.
A worn tank-to-bowl gasket or loose bolts usually cause this leak. Cleaning chemicals, bacteria, hard water, city or well water, can all break down these parts over time.
Since the water flows down the sewer, leaking toilets don't necessarily leave any signs of a leak, until you get the bill. The average leaky toilet can waste about 200 gallons of water per day. That's over 6,000 gallons a month ($70.06*) for just one leaking toilet!
A running toilet is typically caused by the overflow tube, flush valve, or fill valve. Check the water in the tank to determine if it is running into the overflow tube. If the water is running into the overflow tube, the water level might be too high, or the overflow tube might be too short for the toilet.
Shutting off the water supply when leaving for an extended period can prevent potential leaks or flooding while you're away.
Remove your tank lid and observe the water level. If you are doing this in the middle of the night you should visibly see the water going over, or close to it. You can also sometimes see water lines in the tank where the water has risen.