Your Toilet Is Running? How Do You Fix A Running Toilet?!

It happens to everyone, right?  One day you use the toilet just like any day, you do your business, you flush, do up your pants, and while washing your hands you hear it.  Panic sets in as you hear a sound you know but should be around.  Your toilet is running…

Your toilet is running!

This is not in the “then you better go catch it way” either.  No.  This is not just running but running uncontrollably.  It’s not overflowing at least (unless…you know…) but if that is your toilet, meaning you aren’t a renter, it’s time to learn to fix a running toilet.  This is a basic way for ANYONE to troubleshoot and fix a running toilet.

Let’s address some common issues that come up when your toilet is running.


The first thing that goes into any repair job is a troubleshoot first.  We need to understand what is causing the problem.  We then need to find its solution.

Start first by removing the tank lid, unveiling the flushing mechanism.  You should focus on three different parts which comprise the most common issues when a toilet is running uncontrollably:

  1. The Flapper or Tank Ball – connected to the flushing handle which lifts when you flush, exposing the drain for the tank water.
  2. The Plastic Float Ball– large plastic ball floating atop your water
  3. The Overflow Tube – meant to prevent any overflow due to a malfunction (such as we’re discussing now, thankfully we have one).

Once you’ve noticed these three parts of your toilet, give it a flush.  Pay close attention to what happens over the course of a flush.  Does your tank ball or flapper fall back down over the drain pipe but not seal properly?  Does your plastic float ball rise high enough to stop the flow of incoming water?

Should this be the problem, you have a couple of very easy solutions:

NOTE: Be sure to shut off your toilet’s water supply prior to attempting any repair.  You’ll hate doing this with a tank full or water or running water all over the place.

Flapper Issue

Typically if the toilet is running from this, it’s because of the seal between the drain and flapper.

Given the age of many toilets out there, you’ll likely be needing to replace the flapper or tank ball in its entirety.  These are as cheap as they are easy to fix (very is the word I’m looking for here).

I’ve personally experience issues involving a flapper before and all that is required is:

  1. Unlink attached chain of old flapper from trip lever
  2. Remove the old flapper by unhooking the two arms that attach to the overflow tube
  3. Attach new flapper to the studs on the overflow tube and securely place over drain.
  4. Attach chain link to trip lever.

At this point, you should be all set.  Give it a flush just to make sure.

A couple things to keep in mind:

  1. Make sure you measure the approximate length of the previous chain.  Will make your life easier when making sure the flapper will flush properly
  2. Many of the newer flappers are plastic and can cause some issues on older toilets.  If you’re looking for a better seal then this rubber flapper might be better for you.

Once you get everything attached and sealed, turn the water back on to your toilet and give it a flush.  You should be good to go!

Tank ball Issue

Tank balls are an older mechanism of flushing but many are still in use around the world.  Most of the time when a breakdown happens here, it’s simply due to the age of the tank ball where that be the lift rod, the threading where the rod and ball meet, or in the trip lever.

If your toilet is running because of this, you’ll likely need to replace the entire tank ball when a breakdown occurs:

  1. Turn off your toilet’s water supply and flush tank water.
  2. Simply disassemble the existing tank ball, or what’s left of it, and remove the parts which will expose the drain underneath.
  3. Scrub off any gunk around the drain that could prevent a clean seal.
  4. Place the ball portion over the drain prior to connecting the lift rod.
  5. Run lift rod through the rod guide and screw into the top of the tank ball.
  6. Attach to trip lever.

Once you’ve attached everything, turn on your toilets water to fill the tank and give it a flush.  Good as new!

Plastic Float Ball Issue

The plastic float ball can definitely cause some confusion if your toilet is running at will.  The purpose the plastic float ball is to simply close off the ball cock when the water hits a certain height.  This stops water from flowing into the tank and completing the flush.

The usual issue in relation to a running toilet is that the plastic float ball is not rising high enough to close that ball cock.  This means your float ball is either screwed on too much or there is a bend in the float arm.  Typically you can solve these issues without any fix at all.

However, as with many of these old toilets lying around, you might need a complete replacement due to being old.


Our recommendation in a scenario like this is to just replace the entire float ball system with a cost-effective kit, much like you see to the right.  While this looks complicated, it will take you no time at all to complete this repair.  Our suggestion would be to find a great tutorial video like this one from HomeownerSeries.

Here, our tutorial instructor goes into some great depth while also keeping things straight forward enough for the newbies to get. When it comes to semi-complicated installs, you want to make sure everything gets lined up properly.

But at the end of the day, it takes only a beginner-handyman to complete this repair. It’s also the kind of fix that is as rewarding as it is challenging to complete.

Part Swap

If you are fortunate enough you don’t need a replacement, you can buy plastic float balls and float arms or other parts a la carte. Sometimes a solution can be as easy as replacing your old ball so that the water pushes it to the close threshold.

Remember not to over-complicate things.  KISS (Keep It Simple Stupid).

Final Recommendation

If your toilet is running beyond these basic solutions, you may want to bring in a professional. That being said, learning how to fix a running toilet is a skill most will need as a homeowner and even as a renter. The last thing you want is a non-functioning toilet!