Intermittent Toilet Leaks and Running: Causes, Solutions, and Prevention

Most of us have experienced a toilet that runs more than usual, or perhaps it leaks to no avail. This can be not only frustrating but might start to increase your water bill. Eventually, a leaky or running toilet will force you to ask, ‘how do I fix this?’

A toilet may leak because your drain line is clogged, you have loose flange bolts, or the wax ring is old. It could also be the result of a small crack in the toilet bowl, or a leak in the water supply line. You can easily fix these issues by addressing their root problems.

So, stick with me while we discuss the common reasons your toilet will leak or run. We’ll then talk about the best solutions to fix your leaking toilet, so that you can avoid this in the future.

Nobody wants to deal with repeat issues like this, so we will make sure that you don’t have to. At the least, you’ll know how to handle any potential issues later on.

Okay, let’s go!

Common Reasons Your Toilet May Be Leaking 

A leaky toilet is likely a pain in the you-know-what, but it is quite a normal problem to have. So, try not to fret if you’ve stumbled upon this inconvenience. Likely, the issue is not because of something you have done but instead caused by the normal workings of your toilet.

Your Drain Line is Clogged

Your drain line is the mechanism responsible for removing the flushed toilet water out through the pipes. Ultimately, the drain line is what removes used toilet water from your home.

If you notice that your toilet has water leaking from the base, it may be due to a clogged drain line.

How, you may ask?

Well, a clog in this drain line can put some added pressure on the wax ring that sits at the base of your toilet.

If you are unsure that this is the problem, you can always ask a plumber for an evaluation. This doesn’t mean that you must have them fix it, but it might help to confirm your suspicions.

Loose Flange Bolts

Flange bolts are responsible for keeping your toilet securely fastened to the ground. So, when they are loose, you might see some problems arise. A leaky toilet, for example, is a common result of this.

The flange of a toilet is the very base that connects the toilet itself to the hole in the ground that the plumbing goes through.

So, it follows that if the base of the toilet is no longer fully connected, that water will almost certainly leak out of it.

Bolts that can’t be screwed back in might be stripped or could have fallen out of their track. They might need replaced, or the flange itself may need replaced.

The Wax Ring is Old

The wax ring on a toilet relates back to the flange, because it goes around the flange in order to create a seal.

As you may have gathered from the name, a wax ring is fashioned out of wax.

Wax as a product can be delicate, and old wax may no longer act as a good seal anymore. This will lead to water leaking out of the base, even if the flange and its bolts are securely fashioned.

An old wax ring may first make you think that your flange is loose, but if you see that it is secure you should look inside where the flange connects to the floor. More likely than not, you’ll see that the wax is no longer properly molded.

Small Crack in Toilet Bowl

Though toilet bowls are sturdy, accidents can still happen. This is especially common in older toilets that have gotten their fair share of use.

Hairline cracks should not cause major issues, but those that go beyond the surface may lead to leaks when you least expect them.

A small leak like this may not be as noticeable at first, but it could still impact your water bill in a big way.

The Water Supply Line is Leaking

The water supply line is the hose that runs from the base of the toilet tank all the way to the water supply valve.

Most often, this valve can be found in the wall or in the floor, near the toilet itself.

Water can collect at the base of the toilet if this supply line is leaking and can also lead to quite a bit of water finding its way into your bathroom.

Best Fixes for Your Leaking Toilet 

While some fixes may only require a new wax ring, a toilet bowl, a wrench, or some bolts, others may require a professional to come out.

You can always try to DIY a solution yourself before turning to a plumber, if you prefer to handle things on your own at first.

Clean Your Drain Line

Your drain line is one thing that may be able to be fixed by you, but also might require a plumber to come into your home.

If the problem has not progressed much, you can rely on your own devices. If just one drain is clogged, likely in the bathroom with the leaky toilet, the problem is localized.

We recommend pouring about half a cup of baking soda and half a cup of white vinegar down the drain, before pouring some boiling water down. This could get everything moving again and solve your problems.

If there are many drains that appear to be clogged, this indicates a clog in the main sewer line. This is when you’ll need to call a plumber to help you fix the issue in a more extensive way.

The plumber will likely need to use a machine to help clear any debris out of the main system, which should also clear up your toilet’s drainage and solve any leakage going on.

Tighten Your Flange Bolts

Tightening your flange bolts is a process you should be able to do by yourself easily enough.

If you have a crescent wrench or even a good pair of pliers, odds are that this is one root problem that you can DIY your way out of.

Take the plastic caps off of the bolts at the base of the toilet before twisting the bolts in a clockwise direction. They should end up nice and tight, solving the leaking.

If this does not work, your bolts could be stripped or the flange itself may be replaced if the tracks are not quite fitting the bolts anymore.

If this is the case, you can buy your own materials to replace the flange or you can call in a professional to do the heavy lifting for you.

Replace Your Wax Ring

Thankfully, you can find new wax seals, usually in the sizes of 3 or 4 inches, for about $10 at most hardware stores.

Manufacturers have said that these should be easy enough to install, even for first-time users. You can confidently replace your wax ring with the knowledge that you will likely create the perfect seal.

You’ll want to turn off the water at the supply valve and flush the toilet to get all excess water out of your way until the tank is empty.

You’ll unscrew all the bolts and remove the tank first, then the toilet bowl until the flange is exposed.

Next, remove the broken wax ring and scrape any leftover wax away before following the application instructions on your new wax ring.

However, if you prefer to let a professional take over, this is also an option. It will cost you more, mostly for labor, but could be worth the comfort of knowing that everything is 100% fixed.

Check Your Water Supply Line

This one is an easy fix, and really shouldn’t require a plumber unless you really need some support.

You’ll want to begin by turning off the water. Twist the valve on the water supply line, either on the floor or in the wall depending on your plumbing setup.

Next, use your wrench to tighten the nut on the hose, which is the part that should connect to your water tank. After that, you can also tighten the nut on the valve itself.

Finally, turn the water back on by twisting the valve, before flushing your toilet and checking for any continued leaks.

If the water supply line was your issue, this should fix it! If not, you’ll know that it might be time to check for other issues or to call a trained professional that can evaluate your leaky situation for you.

Check Toilet Bowl for Cracks

A cracked toilet bowl may seem like a surface-level, cosmetic issue. Most often, it is.

However, there are certain cases where the crack is deeper than you think, or gets deeper over time, and this could lead to leakage at the base.

You can replace your toilet bowl, but most plumbers recommend replacing the entire toilet at this point.

The cost is not much greater, and this can often be a good time to fully replace your unit to keep water costs down. It can also make sure that potential future issues are kept at bay for longer.

You can do this yourself but might want the guidance of a professional if you do decide to fully replace your toilet unit. It might be worth it in the long run to confirm that everything is properly situated.

When Should You Call a Professional?

Remember, fixing the root cause of problems should be enough to nip them in the bud. However, some issues are bigger than you.

You should always remember that it is perfectly okay to call a professional when a toilet problem feels too complex.

If you have water that is consistently running after you’ve tried to fix the problems above, it may be time to utilize a professional. The same goes for if you have noticed water pooling near the base of your toilet.

Perhaps the water tank is filling too slow after you attempted to fix it, or the toilet won’t flush. It will save you time, and probably money in the long run, to call a trained plumber.

Your attempts to solve the issue yourself could work. However, if you don’t have the time or energy to invest in doing it yourself, a plumber could be the right decision for you.


If you’ve made it this far, we hope that you found some new solutions that can help you solve all of your leaky toilet-related issues.

There may also be other causes for your leaky toilet, and you may want to investigate some additional solutions. Shortening your refill tube, replacing the flapper, and making sure your float is lowered might also help resolve your situation.