Informational Guide

How To Fix A Running Toilet (2023 Guide For Homeowners)

Learn how to diagnose and fix the common issue of a running toilet.

by Ian Haynes

If you haven't already, chances are at some point in your life you're going to face toilet troubles - and we're not talking about those after a spicy meal.

One of the most common toilet problems is a pesky leak, where water is continuously draining from the tank into the bowl. Not only is this a nuisance, but it can be a drain on your water bill.

In this article, we'll help you troubleshoot the most common causes of a running toilet and provide you with some practical advice on fixing them.

A toilet has two essential parts – the tank and the bowl.

The bowl is responsible for holding the water while connected to the plumbing. On the other hand, the tank contains water which is needed for flushing and draining the bowl.

After flushing, the tank automatically refills itself with water for the next use.

To put it simply:

  • Once you pull, push, or touch the flushing mechanism, the flapper lifts, and water rushes from the tank into the bowl.
  • The water fills the bowl while gravity works to pull it down into the trap.
  • Waste and water are siphoned out of the bowl while the tank refills itself, ready for the next use.
toilet anatomy

For an in-depth guide on how toilets work, you can check out this helpful article.

5 Reasons for a Running Toilet

Let's discuss some of the most common reasons your toilet may be continuously running:

  • 1
    Leaking flapper
    Most of the time, a leaking flapper is a culprit for a running toilet. To work correctly, the flapper should cover the hole that connects the tank to the bowl. A poorly fitting or worn down flapper will allow water to run from the tank continuously. The good news is, a flapper is one of the easiest things to fix. Replacement flappers can easily be found online or from your local plumbing merchants. While a plumber can replace your flapper, it's straightforward to do it yourself.
  • 2
    Malfunctioning refill tube
    The refill tube provides your tank with fresh water after each flush and is connected to the main water supply in your home. Blockages, corrosion, or damage can all lead to a malfunctioning refill tube, causing your toilet not to work as expected.
  • 3
    Misaligned or malfunctioning float ball
    The float ball is connected to the flapper and raises and lowers it depending on how much water is in the tank. If it is misaligned or malfunctioning, the flapper may be in the incorrect position, allowing water to flow continuously.
  • 4
    Wrong length of the flush valve chain
    A valve chain that is too short or too long will cause a misaligned flapper, which, as you now know, will lead to continually running water.
  • 5
    Worn gasket
    Being one of the most used features in our homes, your toilet will undergo wear and tear over time. The gasket is the rubber seal that the flapper sits on, and any damage to this part of your system will cause a leaky toilet.

How to Fix a Running Toilet: 5 Easy Steps

While asking for help from a professional is a great idea, doing the repair and maintenance of your toilet might be a better option. After all, hiring someone to do the task can be expensive.

If you have spare time and looking to learn a new skill, fixing your running toilet yourself is pretty easy when you know-how.

Tip: Equipment You May Need To Fix a Running Toilet

To repair and maintain to your toilet, you might need the following tools:

Before we begin, we must first diagnose the problem before moving on to fixing it.

  • First, and most importantly, you need to shut the water supply off. Modern toilets usually have a tap that will allow you to shut off the water easily, but older models may require a bit more work. You can follow this visual guide for a detailed explanation. Once the water supply is shut off, flush the toilet to ensure all the water is removed from the tank.
  • Check the flapper and look for cracks and leaks. If you see any noticeable damage, the flapper is likely the issue, and you'll need to replace it. To change the flapper, just unhook it from its position and swap it out with a replacement. Flappers are inexpensive and can be found on Amazon as well as your local DIY store.
  • If your flapper shows no sign of damage, check if there is a leak on the fill valve. Sometimes, there can be a build-up of residue around your valve that will just need clearing. If you notice any damage to the valve, you'll need to replace it.
  • Removing the fill valve is an easy process, as is replacing it. Once again, as it is such a common issue, replacement fill valves are readily available - just make sure you get the right measurement for your toilet.
  • After diagnosing the problem and fixing it, you can turn back on your water supply. Once the tank has refilled, look and listen for leaks to check there are no further issues

People also Ask (FAQs)

How much does a running toilet increase the water bill?

A severe running toilet can waste up to 4.5 gallons per minute, or 300 gallons per hour. At this rate, it can increase your water bill by around $60 a day – very costly.

Why is my toilet making a running noise?

Most of the time, a running toilet indicates an issue with the flapper, valves, or perhaps due to debris and calcium deposits inside the pipes. Follow our steps above to diagnose and fix the problem.

How do I stop my Kohler toilet from running?

You can follow our five-step process above to diagnose any issues with your Kohler toilet.

Why does my dual flush toilet keep running?

Most of the time, the issue is the flapper or the seal. The flapper is responsible for holding the water in the tank until flushed, so a misaligned or damaged flapper can cause a toilet to run continually.

A common problem with dual flush toilets is buttons' sticking' or being held in the flush position. Double-check that your buttons are not stuck and loosen them if they are.

toilet button
How do you fix a push button on a toilet that keeps running?

Evaluating your tank to determine the possible cause of the running toilet is essential. A misaligned valve, worn flapper, or a poorly fitting float ball are often the culprits for a toilet that keeps running. Likewise, a jammed button can be a common cause, so double-check there is no issue here.


So there you have it - who needs an expensive plumber when you can diagnose and fix your own running toilet issues!

Running toilets are one of the most common issues homeowners face but also one of the easiest to fix, and after you've read our guide, we're confident you will be able to do so.

Ian Haynes is an expert writer who has successfully deployed over 500 plumbing pages and other related content. He has an excellent understanding of home plumbing issues and translates his experiences via Plumbing Lab so readers can have a better understanding of common household problems. Outside of his work, Ian likes exploring Brooklyn with his Labrador.