When a toilet leaks in your house, it can cause you serious troubles, threatening the foundation of your property. Flooding can cause expensive and even irreparable damage.
Let’s take a closer look at why your toilet may be leaking so you can quickly diagnose and resolve the problem!
Table of Contents
- 1. Leaking Directly from the Bowl
- 2. Leaking Between the Tank and Bowl
- 3. Toilet Leaking When Flushed
- Water Supply Lines
- Final Thoughts
Although it might look simple, the toilet consists of many parts that ensure it works properly. There are various seals, valves, wax rings, and other parts that can cause leaking if damaged. Furthermore, cracks in the toilet itself can quickly cause damage if you don’t notice them right away.
A good place to start diagnosing why your toilet is leaking is to identify from where exactly the toilet is leaking. In general, it could be leaking from the bowl, between the tank and the bowl, or when it flushes – each of which can be caused by different issues.
1. Leaking Directly from the Bowl
If you think your toilet is leaking from the bowl, start by ensuring that the toilet isn’t cracked. You’ll want to call a professional immediately if you do notice any cracking in the toilet itself. If you don’t see any cracks, however, there are a few actions you can try to resolve the issue:
Fixing the Seal
A damaged seal is the most common cause of leaking, mostly because it can be damaged in many ways. For example, you might not notice the leaking in your bathroom, but you’ll see water damage in the room below the toilet.
Another issue could be that the toilet isn’t bolted down enough. As a first step, check both the seal and the bolts to make sure they’re working as expected. If the seal looks off, you’ll want to replace it completely – you can follow the directions below to start that process. If the bolts are loose, tighten them carefully to fully secure the toilet. However, make sure not to do it too tight, or you might break the porcelain.
Taking the Toilet Apart
If you need to remove the seal, you will need to take the toilet apart. Luckily, it’s much easier than it sounds. While taking the toilet apart, you can also look for any other damaged parts.
- To start, turn off the water supply to your toilet and flush once. Make sure to hold down the flush lever until the tank empties completely. After flushing, use a sponge to remove any remaining water.
- Then, unscrew the water supply tube from the valve to loosen it. Remove the bolts from each side of the toilet, using a wrench and pliers if needed. When you’ve detached the toilet, put it aside on a piece of cardboard or towel.
- You may notice the sewer gas that comes from the piping, so put a rag into the pipe to block it.
- Finally, use a putty knife to remove the existing seal, then clear the floor from debris to expose the flange.
Checking the Flange
Most probably, if your toilet leaks, you have a problem with the flange. The flange is a pipe that attaches to the toilet and secures it to the floor. However, replacing the flange is difficult, so the best idea is to install a reinforcement ring instead of a totally new flange.
Simply clean the flange and drill a clearance hole, then put caulk around and place the reinforcement ring over the flange. Bolt it together and wait for 10-12 hours before putting the toilet back.
If the flooring in your house is relatively new or installed after the toilet, the flange might be too low. In that case, you will need to install an extender ring.
Is the Floor in Good Condition?
While the toilet is removed, make sure to check the area around the flange. You should poke it with a screwdriver to make sure that it’s still solid and not rotting. If there is a little bit of rot, you should install flange support. That way, the support reinforces the floor and you will prevent any further damage.
Remounting the Toilet
After completing these steps, you can now remount the toilet. Place the new wax ring over the flange and put the bolts in place. Remove the rag from the pipe and put the toilet in the right position. You can also check that everything lines up by sliding the closet bolts. If everything fits properly, seal the toilet with your body weight.
Turn on the water supply valve, and when the tank fills up, flush it once to check if it’s leaking. If it is, you might have problems with the connector pipe, which would require a plumber.
2. Leaking Between the Tank and Bowl
If the toilet is leaking between the tank and the bowl, the first thing to do is to determine the cause. For example, the source of the water could actually be the toilet tank sweating. This situation usually occurs when the temperature of the water inside the tank is lower than the temperature in your bathroom. If you aren’t sure if the toilet is leaking from the tank or if the tank is just sweating, we have a quick and easy test to check. For this test, you’ll want a non-permanent water dye. Remove the tank lid and add the non-permanent water to the dye. Let it sit for 10-15 minutes, and then check the water leaking from the tank. If the water matches the dyed watercolor from your toilet, you’ll know it’s not just condensation and you have a larger problem.
If you do confirm that your toilet is leaking between the tank and bowl, a few different parts could be the cause. For example, if the water comes from near the center between the tank and the bowl, you might have to buy a new sponge gasket. If the issue persists, you might also have to replace washers for bolts. If the toilet leaks even more when you flush, you will have to replace the bowl gasket. On the other hand, if the leakage occurs from the sides, your washers and bolts are in a bad condition and you should replace them. Ultimately, identifying where your toilet is leaking will help you assess the overall damage as well as what parts to replace. Remember, when you buy new parts, make sure that they match your toilet model.
If you can’t actually decide where the leaking is coming from, it could mean that your shank gasket is not working properly. If you don’t know how to locate the shank gasket, it’s usually in the place where the fill valve is attached to the tank. Since the problem is still related to the tank, the water dye test discussed above will still work to detect this issue.
To fix your shank gasket, make sure to check for any possible cracks in the porcelain around the gasket. If everything is fine, simply turn the gasket about a quarter of a turn to tighten it. However, if this action doesn’t resolve the problem, you will need to buy a new gasket.
Other Possible Issues
Another possible cause of the leaking could be that your refill tube is too loose, especially if the leakage occurs from the back of the tank. Try to tighten the tube if possible, or you may need to consider a replacement. Ultimately, as you’re looking for other issues, always be on the lookout for tiny cracks in the porcelain. Unfortunately any cracks are usually impossible to fix, and even though they can be small, they will still cause leaks. If you do have cracks in your toilet porcelain, you will need to get a completely new toilet to permanently resolve the issue.
Taking Apart the Toilet Tank
To address many of the issues above, you’ll need to take apart your toilet tank. Follow the below steps to dismantle your tank:
- Like before, start by turning off the water supply line. Flush to empty the tank, then use a sponge to remove any remaining water.
- Next, disconnect the inlet tube from the toilet. Check the lines now. We recommend replacing the washers and the supply tube at this point.
- If you have a 2-piece toilet, unbolt the tank from the bowl and take a look inside the tank. You will notice that there are two slotted screw heads that you will need to remove. If the screws won’t come out, you can use a drill to help remove them. However, make sure to be careful the porcelain is prone to cracking and breaking.
- Next, for a 2-piece toilet, lift the toilet tank and peel off the seal. Use the old seal to purchase a replacement that’s exactly the same. You can also pick up a new tank-to-bowl bolt kit to help attach your tank with the new seal.
- While the tank is removed, make sure the gasket isn’t cracked and everything looks okay. Then, place both metal and fiber washers on the bolt and slide it onto the tank holes. Secure it with a nut to ensure a leak-proof seal.
- Take the tank and put it over the bowl, making sure that everything’s aligned. Now, you will need to carefully tighten the bolts.
- Now, it’s time to test if the problem is solved! Pour a few liters of water in the tank before you turn on the water supply to check if the tank still leaks. If the issue persists, you’ll likely want to call in a professional to help.
3. Toilet Leaking When Flushed
If your toilet leaks only during flushing, you might have one of these five problems:
- Cracked toilet tank or base
- Loose supply valve
- Loose-fill valve
- The flapper doesn’t shut correctly
- Loose nuts and bolts
Most of the above will be resolved by following the steps above to take apart the toilet and the tank. You can also check each specific part listed above to rule out potential issues. A toilet leaking from the base could signal further issues. Also, any cracks in the toilet tank or toilet base, in particular, will mean you want to call a professional immediately to help fix or potentially replace your toilet.
If the Flapper is the Problem
The flapper is a component of your toilet tank that moves when you flush. Basically, it lets the water go through the pipe and reach the bowl. However, if the flapper’s not working properly, the toilet will leak, or it will flush twice.
Like when we tested the tank, you can test your flapper by adding a few drops of water dye or food coloring to your tank. If you notice the colored water leaking into the bowl when you haven’t flushed, it means that the flapper is not sitting as it’s supposed to. Remove the lid and check the flapper. If the rubber is not soft, you should buy a new one at any hardware store. Then, replace the flapper and test the water again to make sure it’s no longer leaking.
Water Supply Lines
If you don’t notice water leaking from the toilet itself, you could have a problem with the water lines. If either inlet or outlet pipes are damaged, they can cause leaking in your basement. You need to make sure that they are properly sealed at all joints and don’t have cracks. Also, the pipes must be capable of handling the current water pressure and volume. If there is a problem with your pipes, you will need to either fix or replace them, depending on the damage. It’s best to call the plumber as soon as possible if you do think your pipes are the problem.
Even if you have a new toilet, it might start to leak over time. And, unfortunately, if you don’t fix the problem quickly, leaking can lead to serious problems in the future. However, as you can see, fixing the leaking problem doesn’t have to be difficult or expensive. Make sure to be careful when following the steps listed above and you could fix your problem in no time!