Toilet Leaking? 9 Reasons Why You Have a Leaky Toilet

May 6 2024

There is perhaps no other fixture in our home that is as trustworthy and well-used as the toilet. Besides regular cleaning, the cost of toilet maintenance is considered to be relatively lower than that of other fixtures in the home. 

However, if something goes wrong with the toilet, your sanity may be called into question. A simple toilet leak can result in a pool of water and cause issues like floor and wall damage or fixture inefficiencies. If left unfixed, your utility bills may increase monthly. 

In this blog, we’re going to ease your worries and break down the most common causes behind leaking toilets as well as help you identify toilet leaking signs and what you can do to fix them.

1. Damaged Flapper

Toilet flappers, a plastic or rubber component, are one of the toilet tank’s most important parts. It acts as a barrier between the tank and the bowl and a seal to keep the water in the tank. Over time, this part can crack or deform and fail to control the water flow, causing a leaking toilet tank.

A deteriorated flush valve (flapper valve) is another common cause of a toilet tank leaking. If the flapper does not sit properly on the flush valve seat, water will leak into the bowl. To find out if you have a damaged flapper or loose flush valve, listen to the toilet’s sound after you flush. Hearing continuous water trickling is a dead giveaway.  

How to Fix a Damaged Toilet Flapper

Here’s what you need to do to fix your leaky toilet if the cause is a broken flapper:

1. Shut off the water then open the tank.
2. Unhook the chain from the handle and unloop the old flapper from the flush valve’s mounting ears.
3. Get a new toilet flapper that’s the same size as the old one. Hook the chain to its top ear, then attach its loops to the mounting ears.
4. Run the water and flush to see if you still have a running toilet.

→ Read more: Here’s Why Your Toilet Tank is Not Filling

2. Stuck Flapper

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A toilet flapper leaking could be the cause of a stuck flapper. Even when your flapper is in good condition, it may not stay as intended or stick in its closed position. In this case, the flapper stays lifted or in an open position, allowing water to flow continuously from the tank to the bowl. If this is happening in your toilet, check the flush handle to see if it feels floppy and unresponsive.

How to Fix a Stuck Flapper

If your leaking toilet is caused by a stuck flapper, here’s what you can do to fix it:

1. Lift the tank lid and see if the flapper is still connected to the flushing handle. 
2. If it isn’t, attach the chain to the flapper and position it correctly on top of the flush valve. 
3. If that doesn’t work, replace the flapper’s chain and adjust it to its correct length. Doing so can help the flapper to close and open all the way. 

If you need a new flapper or chain, you can find one in toilet repair kits sold at hardware stores.

→ Read more: 5 Reasons Why Your Toilet Isn’t Flushing Fully

3. Faulty Toilet Float

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A toilet float, also known as the ballcock or float valve, is a ball that floats on top of the water in the toilet tank. It’s connected to the fill valve and regulates the tank’s water amount. When the ball falls to the bottom, it signals the fill valve to open and let water flow inside the tank. As soon as the float reaches the top, the fill valve automatically shuts off and stops water from entering.

Because of wear and tear and mechanical damage, the toilet float and fill valve can malfunction in spite of regular maintenance. Their unresponsiveness lets the water run continuously and causes a toilet overflow. 

How to Fix a Faulty Toilet Float

If you notice a slow water leak in the toilet bowl, or water leaking from the toilet tank, here’s what you need to do:

1. Turn off the water supply to your toilet. 
2. Flush the toilet to remove the water in the tank. Remove the remaining water with a towel or dipper.
3. Use pliers to unscrew the arm of the old toilet float and remove it.
4. Check the height of the new float and adjust if necessary.
5. Insert the valve into the tank inlet hole while ensuring the rod arm position provides room for the float ball to move.
6. Screw the new toilet float into place. 
7. Turn on the water and see if your leakage problem has stopped.

Just as with the other items on this list, call in the experts to help you fix a leaking toilet if you want to be sure of getting a solution that will last you years, without any hiccups.

→ Read more: Wondering how much a plumber costs in Ontario? Click here!

4. Rusted Toilet Fill Valve

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If your toilet tank is leaking and not because of a faulty float, then the toilet fill valve leaking is the main culprit. This valve controls the water flow into the toilet tank when paired with the float. It ensures that your toilet tank is full to the necessary level. 

The fill valve on your toilet will go through wear and tear over time. Mineral deposits can also accumulate on it, causing damage. These issues can cause the fill valve to not shut off and lead to a leaking toilet. 

When you have a rusty or damaged toilet tank fill valve, there’s no other fix than replacing it.

How to Fix a Rusted Toilet Fill Valve

Replacing the fill valve isn’t too complicated, but it’s important to diagnose the issue accurately beforehand to avoid further damage. If you’re unsure about this DIY process, turn off the water supply then call a professional plumber. The experts can advise you on what fill valve will last you the longest.

If you feel confident to fix it yourself, here are the steps to fix your fill valve:

1. Shut off the water supply to your toilet and flush it to remove the remaining water.
2. Remove the supply line from the tank.
3. Remove the existing fill valve.
4. Adjust the height of the new fill valve and install it into place.
5. Reattach the supply line to the toilet. Turn the water on once again and see if any of the previous problems persist.

5. Broken or Leaky Supply Line

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The flow of water is directed to the toilet water tank through the water supply line. When the line works properly, it remains a closed system. However, the supply line can crack and break down over time due to high water pressure. You may see the toilet leaking from the base or the bottom of the tank, and the water spreads on the floor. 

Leaks usually happen when joints in the supply line grow weak or become loose, causing the toilet to leak from the pipe at the back. The rubber lining within the supply line, which is there to prevent leakage, can also rupture. This is either caused by gradual wear and tear or mechanical damage to the supply line.

→ Read more: Do you hear hissing sounds from the toilet? Here’s why it happens

How to Fix a Broken or Leaky Supply Line

Before you ask “Is a leaky toilet an emergency?” we’re here to tell you it is—especially when the cause is related to your toilet’s water supply line. 

If the toilet supply line or hose is leaking, call an emergency plumber for prompt assistance. Remember, this is critical and needs an expert to minimize damage to your toilet and home. Doing so can help you save time, effort, and money trying to fix it on your own. 

6. Damaged Toilet Tank

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A toilet tank holds water inside it to refill the bowl again and again that the toilet uses for its flushing mechanism. If you see water on the floor around the commode, it could be because of a damaged tank. 

A toilet leaking from underneath happens when the bowl is either cracked or broken. Even hairline cracks could cause toilet leaks, and these kinds of small cracks are the hardest to detect.

How to Fix a Damaged Toilet Tank

If your toilet has minor cracks, follow these steps: 

1. Shut off the toilet water supply, then remove the tank water by flushing the toilet. 
2. Use either a porcelain sealer or epoxy and apply it over the crack. Start an inch above the crack and slowly trace through the crack.
3. Smooth out the sealer with a plastic knife and let it dry for at least 24 hours. Once done, turn on the water again and check if the leak is still present.

However, large cracks and leaky tank bolts need a toilet replacement. Call your local plumber for installation assistance.

7. Toilet Bowl Damage

If the toilet leaks when flushed, it could be because of a leaking toilet bowl. The toilet bowl is installed to hold water but can drain directly onto the toilet floor when damaged. This can be due to cracks that cannot be fully sealed with glue or putty. 

How to Fix Toilet Bowl Damage

If you find that the bottom of the toilet is leaking because of any structural part cracked, the best way to fix the problem is by replacing the entire toilet unit. 

Whether your toilet is leaking from underneath or anywhere else, you need to take the necessary initial steps—the small things can quickly add up to a huge cost with time. 

For instance, they can add to your water bill, destroy bathroom tiles and subfloor, and stain toilets. Moreover, accidental falls can be dangerous for you and your family. If you can trace the toilet leaks, call a plumber to fix your leaking toilet.

8. Cracked Connectors

Just like any plumbing fixture, toilets have multiple connectors that enable water flow and prevent the toilet from leaking. If any of these water supply connectors lose their seals, water will seep through the fixtures and leak out on your toilet floor. When this happens, you can see the toilet leaking at the base.

How to Fix Cracked Connectors

If the toilet shutoff valve is leaking, seek assistance from a plumber to avoid any further mishaps. They can routinely check the connections of your toilet to detect any issues before they crack or leak.

Most importantly, choose high-quality parts to replace the fixtures and prevent issues like a leaking toilet pipe when fixing a leaky toilet. 

9. Broken Wax Seal on the Bottom of the Toilet

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The wax seal under your toilet is an impermeable barrier that keeps flushed water and sewage from leaking onto the floor. If the toilet is leaking when flushed only, it’s probably because of this. The loose toilet floor seal allows puddles to form in the bathroom, making it an urgent repair. 

In addition to water accumulating at the base of your toilet, you may also smell a lingering, unpleasant bathroom odour. Your toilet may also wobble if this is the issue.

How to Fix the Broken Wax Seal of a Toilet

Wear and tear is the most common reason for damage to your toilet’s wax seal, and it could need a replacement. Replacing the wax seal under your toilet is not something recommended for DIY. The process is meticulous and slight mistakes can mean you’ll face the same or worse problems.

This is a fairly complicated process that is best left to the pros. With an expert on the job, you’ll be sure to have the best quality wax ring installed securely that will last for years to come.

Call 1st Rooter to Fix Your Leaking Toilet Issues 

A leaking toilet can be caused by visible and invisible issues that require professional attention. While opting for DIY options can save you money, it’s possible you won’t detect the root cause of the issue, potentially causing more costly repairs down the line. That’s why you should fix this the 1st Rooter way.

1st Rooter is Ontario’s leading plumbing company that ensures your fixtures and fittings are dealt with correctly the first time. We handle all sorts of plumbing services, from toilet installation and water leakage fixes to repair and maintenance. Our licensed and experienced plumbers can fix and prevent all toilet-related problems, so you can have peace of mind.

Call us for a repair or service, and we’ll be there in no time!