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Toilet Still Leaking After Replacing Bolts, Valve, Seal, etc.

Is your toilet still leaking after you replaced the bolts, valve, water line, seal, gasket, and any other parts you could think of? You may feel there’s no hope to fix your leaking toilet, but don’t give up just yet! 

This is a complete guide to fixing your leaky toilet. We’ll walk you through a checklist of parts to replace and discuss what to do if replacing those parts didn’t work. 

Leaking toilets are a hassle, and frankly, gross. Before you resort to calling a plumber or replacing your toilet, read this comprehensive guide full of tips, tricks, and solutions for your leaking toilet. 

Toilet Still Leaking After Replacing Bolts, Valve, Seal, etc.

If replacing all the toilet parts doesn’t work, you may have a clogged drain line, warped floor, or cracked toilet. In most cases, it’s time to call a professional plumber. But this article will discuss why it’s still leaking and possible DIY solutions. 

How Toilets Work

Toilets are complex appliances that most people don’t understand. Unless you’ve fiddled with a toilet or you’re a plumber, you probably don’t question how they flush and refill, you’re just happy that they do!

This section will give you an overview of how toilets do what they do. Knowing the process behind your toilet’s functioning can help you better identify the problem and familiarize yourself with the various components of a toilet. 

  1. When you push the flush handle, it lifts a flapper at the bottom of the flush valve, letting water flow into the bowl. 
  2. Thanks to gravity, the rushing water flows into the trapway, which is the pipe angled upward.  
  3. The water siphons out of the toilet and down the drain. 
  4. As the bowl empties, it refills with water supplied from the fill valve. As the water levels rise, the floater rises, and the fill valve shuts off. 

And that’s it! As you can see, many components work in harmony together. If even one is worn or damaged, the whole system collapses, and you’re stuck with a leaky toilet. 

Parts Checklist

As mentioned, toilets are not the simplest of appliances. You may think you replaced every possible replaceable part. But to be sure, this section can act as a toilet parts checklist for you to reference. 

Review this checklist and confirm you replaced all of these parts before trying different solutions. 


Bolts are the easiest part to replace and are often the sole cause of a leaky toilet. The bolts secure the toilet to the floor, which connects to your water tank and sewage system. If the bolts are old, misaligned, or slightly loose, this can lead to water leaking from the base of your toilet. 

First, try tightening the bolts as much as you can and see if the toilet still leaks. If that doesn’t work, replace the bolts completely, most toilets have four bolts. For extra stability, you can add washers to the bolts to ensure the best seal possible. 


Valves are tricker than bolts. The fill valve is an integral component of the toilet, filling the bowl after you flush it. The fill valve is in the toilet tank, so you must cut off the toilet’s water supply before replacing it. 

Make sure you use the correct fill valve for your toilet. Another valve you may need to replace is the flush valve. Flush valves typically don’t cause leaks, but it’s not too expensive to replace if you want to cover all your bases. 

Water Line

The water line is the metal or plastic tube that connects your toilet to the clean water supply to refill it (see our post about toilet water supply lines for more information). It’s usually on the lower side of the toilet and goes into the wall or floor.

If you have an older toilet, this part wears and fractures over time, especially if you’ve been replacing toilet parts and moving the toilet around a lot. Before you replace the water line, ensure it’s securely fastened on both ends. A leak could simply be due to a loose washer on one end. 


One of the most important toilet parts, and also the most finicky, is the wax ring gasket that connects the toilet tank to the toilet bowl. 

Replacing this seal can be a hassle, as you must remove the toilet tank and scrape off the old wax seal to apply the new one. However, if your toilet leaks from the back of the bowl, it’s almost definitely a worn or damaged wax seal.


The flapper is part of the flush valve in your toilet. You can replace a flapper without replacing the whole flush valve, saving you money. 

A worn flapper or damaged one won’t successfully start and stop water flow into the toilet, resulting in leaks. You’ll find the flapper at the bottom of the flush valves at the bottom of the toilet tank. Check it for any damage, looseness, or misalignment. 


Another vital component is the one that connects the bowl to the floor. Not the bolts on the side, as this seal is underneath your toilet and not visible. This seal is wax-free, unlike the wax gasket that connects the tank to the bowl. 

Examining Your Leaky Toilet

If you replaced all the parts above and are still scratching your head as your toilet leaks, examine your toilet to try and find the real reason it’s leaking. Consider the following questions when determining the cause of the leak. 

Where Is It Leaking?

Where is the water coming from? Examine the source of the leak. It could come from the back of the bowl, the top of the tank, or near the floor. 

If you’re struggling, add a few drops of food dye to your toilet tank and flush or wait for the leak to begin again. Look for the colored water, and boom, you found your leak. 

Leaking Toilet

How Much Is It Leaking?

Little drops of water could mean condensation. But large puddles signify a faulty toilet and likely a broken component. There’s a big difference between a toilet that drips and when that gushes water. 

When Is It Leaking?

If the toilet leaks all the time, there’s likely a crack, loose seal, or loose bolt somewhere. But most leaky toilets leak when the toilet flushes. 

If this happens, the fill valve or water line is usually to blame. A toilet that leaks all the time is far more troublesome than one that only leaks when flushed. 

Reasons Your Toilet May Be Leaking and Solutions

If you replaced all the parts above and the toilet still leaks, one of the problems below could be your issue. 

Loose Base

If you tighten your bolts as much as possible, but your toilet is still a little wiggly, the problem is likely a loose base. Usually, replacing or tightening the base bolts will solve this. But it could be an issue with the floor or something underneath the toilet. 


If new bolts didn’t do the trick, add shims into the gaps between the floor and toilet. In this situation, locate the gaps, insert the shims, and then trim the shims. For added protection, use a caulking gun to seal any holes between the shims and create a tight seal. Make sure you use a plumber’s caulk, which is more resistant to water. 


If you correctly replaced all the parts discussed above, a likely cause of the “leak” is condensation. The good news is this is not a leak at all! The bad news is you still have water on your floor, making you uncomfortable. 


To reduce condensation in your bathroom and keep your floor dry, try one or more of these solutions:

  • Install an exhaust fan
  • Keep your bathroom at a warmer temperature
  • Add a drip tray below the toilet tank
  • Add insulation panels to the inside of the toilet tank

You can find most of these fixes at your local hardware store. Some people dislike the drip tray, as they don’t see it as a real solution (read here for more information about a dripping toilet). And controlling only your bathroom temperature can be difficult. Insulation panels are often the best solution to try first. 

Faulty Seal

A faulty seal is one of the most common problems, and replacing it with a new seal isn’t always the solution. Certain toilets and seals require pressure or suction to secure the seal. Even a brand new seal could be your problem. 

Unfortunately, many hardware stores sell “universal” toilet seals, but these tend to be unsuccessful. It’s best to steer clear of any “universal” parts, as different manufacturers use different-sized pieces and materials to craft their toilets. 


Determine the make and model of your toilet and find the appropriate seal. Sometimes ordering a replacement part from your manufacturer is the best option. 

Replace the seal with pressure. If it doesn’t look as tight as it should be, it probably isn’t. Consulting a hardware store employee or plumber on what seal is best for your toilet can be helpful. 

Misaligned Overflow Tube

The overflow tube is the short plastic tube inside the toilet tank that attaches to the top of the fill valve. If this tube is in water at all times, it can cause the toilet to leak because it thinks it needs to refill itself. 


This one is super easy! Just move the overflow tube, so it isn’t submerged in the water. Instead, when the toilet idles, it should hover just above the water line over the flush valve. 

Clogged Drain

Clogged Drain

If you replaced all the parts and the toilet continues to leak, a clogged drain line could be the issue. The drain line is usually in the wall or floor behind or underneath your toilet. So it isn’t one of the first parts people think to replace. 

If you’ve been plunging your toilet more than usual and the bowl flushes super slowly, it’s likely a clogged drain line. 


To deal with a clogged drain line, you have two options: replace the drain line or unclog it. Most people recommend hiring a plumber for both of these tasks. But if you want to DIY it first, you can give it a go. 

To clear the clog, pour boiling water and dish soap into your toilet. This combination can loosen the clog and help it move down the drain line. To replace the drain line, you often have to remove the toilet and deal with the plumbing in the wall or floor. 

Cracked Toilet

A cracked toilet almost guarantees a leak. If your toilet cracks in any spots, it’s the likeliest cause of your leak. Carefully examine your toilet from all angles to see if you can locate any cracks. They can be as thin as a piece of hair, so look carefully. 


Depending on the crack, you may need to replace your toilet or call a professional. But if the damage is small, you can try to seal it yourself using putty, epoxy, or caulking. Make sure your toilet is completely dry before doing this. 

Weak Bathroom Floor

Lastly, your leaky toilet may not be the toilet’s fault. If your bathroom floor is weak, damaged, worn, or warped, it can cause the toilet to leak from the bottom. If you tighten and replace the base bolts and it still wiggles, your floor might be the culprit. 


Fixing a floor can be a serious project. You can try the shim trick discussed above if you think your floor is warped. You can also try to reinforce the floor just beneath your toilet. 

When to Call a Pro

If at any point you feel like you’re in over your head, call a plumber. If you’ve already tried replacing everything, it’s probably time to ask a pro for help, as you’ve exhausted the list of common toilet problems. 

When to Replace Your Toilet

A professional will advise you to replace the toilet if necessary. But if the toilet has a massive crack, you can assume it’s time for a new one. 

Bottom Line

No one wants a leaky toilet, but buying a brand-new toilet isn’t ideal either. If you’re a do-it-yourself person, take a crack at finding the problem and try some of the tricks here to fix it. But in the end, there’s no shame in calling a professional!

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