My Toilet is Leaking!

AllClear 5:10 pm

My Toilet is Leaking!

There’s hardly a day that goes by that All Clear Plumbing doesn’t receive a call from someone exclaiming, “my toilet is leaking!” While we can solve any toilet-related problem, “a leaking toilet” is not enough information to diagnose the issue. A lot can break on a toilet from top to bottom, inside and out. But never fear, we have a complete guide to leaky toilets right here:

First, let’s get our basic terminology set, with the help of this diagram:

toilet leaks
Your Toilet Keeps Running

A running toilet is usually a sign of worn out parts. Water, especially moving water, can break down nearly any material over time. Think about those smooth river rocks in a stream. Now, imagine how plastic and metal fare over several years.

Most toilets have several working parts inside the tank including a flapper, fill valve, overflow, chain, toilet bolts … you know what, let’s just give you a diagram.

toilet tank leaks
If your running toilet sounds like the tank is filling up over and over, a good culprit might be the fill tube assembly. Water dripping in the toilet tank or if you notice a slow leak into the bowl is usually caused by a worn out flapper.

Regardless of what tank part is going bad, All Clear Plumbing recommends that if you’re replacing one part, you should replace them all. Typically, these parts get installed at the same time and start to go bad at the same rate. Therefore, it is often prudent to do what we call a “tank rebuild.”

You can buy a tank rebuild kit at a home improvement store if you want to do it yourself. This costs only slightly more than each part – which is true for having a professional install it as well. You’ll save time and money in the long run doing it all at once!

You Notice a Slow Leak Into the Bowl

If you suspect or notice a slow leak into the bowl of the toilet, there is one surefire way to figure out if there is actually a leak. Put a few drops of food coloring into the tank. Leave the toilet alone, without flushing for several hours. If you come back to find color in the bowl, you have a leak. Of course the color will show up in the bowl the next time you flush, but that’s okay.

These sorts of leaks are usually the result of a worn out flapper, but the advice is the same as above. All Clear Plumbing recommends a whole tank rebuild, and not individual parts.

There’s a small chance, if your toilet is very old, that the porcelain itself gets worn to the point that you can’t get a good seal on the tank anymore. Toilets do wear out over time, so if your toilet is over 15 years old consider replacing it.

In review, you might need to rebuild your toilet tank if:

  • Your toilet keeps running
  • You notice a slow leak into bowl
  • There is water dripping in toilet tank
  • Toilet leaks at base

A toilet that leaks at the base can damage flooring and subflooring quickly, so don’t let this type of leak go on for too long. It needs immediate attention.

Leaks at the toilet base are typically caused by either a broken wax seal or loose toilet bolts. If you have recently installed new toilet, and there is a leak from the base of toilet then you might want to try tightening the toilet bolts first. This takes two seconds and simple tools, so it is always worth checking. If you can move the bolts with just the strength of your hand, they are definitely too loose.

A leaking wax seal on a toilet, or what’s sometimes called a broken seal on a toilet, can usually be fixed by replacing the wax ring. Sometimes the leak will only happen during a flush, but it’s important to make sure you figure out the real cause of the leak. Sometimes we think that the toilet is leaking from the base, but it is actually water dripping down the outside of the toilet.

Make Sure the Toilet is Actually Leaking from the Base

Here’s how to double-check the source of a leak:

Clean up all existing water very thoroughly. Now that you are dry, use toilet paper to wipe around the base – anywhere you suspect the leak might be from. If there is no evidence of water, try flushing your toilet and wiping again. Toilet paper makes it very easy to see the water and find the drip or small leak quickly, before it starts to settle to the lowest point of gravity.

A New Wax Seal

A new wax seal involves turning off the water to the toilet, flushing the existing water out of the tank and bowl and wet-vacuuming out the rest. Once the toilet is dry, you can remove the toilet bolts and pull the toilet.

Never set a toilet down on the floor! Always place it on an old piece of cloth or a scrap piece of cardboard. Part of the old wax seal will be on the toilet and that stuff is impossible to remove! It will also stain clothing.

Wax seals are tricky. Don’t touch the stuff if you can help it. Pop the seal out of the plastic and place it in the flange. Then, sit the toilet back down on the seal. While straddling the toilet, slowly and carefully rock the toilet back and forth to create the wax seal. Creating that seal is the difference between a flood and no flood. If you aren’t sure if you can swing this repair, it’s best to call All Clear.

Toilets leak at the base more during a flush because of the pressure being pushed through the flange. If the flange itself breaks, you definitely need to call in a pro. Casual DIY-ers should beware of trying to make this kind of repair.

If you just installed a new toilet that is leaking at the base, you probably just didn’t get the toilet seated correctly on the wax ring. You might want to let us try. Again, damage to subflooring happens quickly and is very harmful to your homes structure. A single flush is several gallons of water worth of damage and extraction services are expensive.

Leaking Shut Off Valve on Toilet

If the leak is actually coming from the shut off valve near the wall, that is a completely separate issue from the toilet parts. This usually only happens after you’ve fiddled with it, since these valves go so long between active use.

One important tip for working on your shut off valve:

Hold the stem tightly.

By that, we mean to anchor the pipe coming out of the wall, so that it doesn’t twist with the valve. If you have very old pipes or plastic pipes, this is very important. Worst case scenario is that shut off valve coming off in your hand and water going everywhere. If you are nervous about this, it’s best to turn off water to the entire house before proceeding with a repair to the toilet.

Use groove joint pliers to turn it 1/8th clockwise.

If this doesn’t work, the valve might need replacing. This might be a good time to call All Clear, but definitely turn off the water to the entire house before attempting this repair.

The Cost of Toilet Leaks

The average home leaks an average of 10 gallons of water per day – that’s money down the drain! Be proactive and check for leaks in your plumbing regularly.

Understanding the basics of toilet structure and repair can help you self-diagnose and perhaps tackle some of these DIY projects yourself. It’s just important to know your stuff before you dive in and we hope that this article goes a little ways towards accomplishing that.

Still have questions? All Clear Plumbing is always happy to help you troubleshoot over the phone or come out and help with your plumbing repairs. Just give us a call, shoot us a text, or send us a message online.

Article Author: Anja Smith

Managing Partner

Anja Smith is the author behind the All Clear Plumbing blog. She also writes regularly for Plumber Magazine,, and on Medium