Chapman Plumbing

How To Identify And Fix A Running Toilet


A running toilet can be a real hassle, especially if you have guests coming over. The water will still be running when they arrive and they’ll hear the gurgling sound of waste floating in the bowl. When a toilet runs, it’s not just annoying — it can also be dangerous. If your toilet is constantly running, you may have an issue with the flush valve.

According to the National Sanitation Foundation, a toilet needs to be flushed at least twice every five minutes. Many people don’t flush their toilets enough, which can cause problems like clogged drains and backups. The most frequent reason for toilets to leak is excessive wear on the flapper valve and its connecting parts.  How do you know what the problem is? Well, let’s get you started on that task.       


Understanding How a Toilet Works

The toilet is a device that can be used by everyone, whether you are an adult or a child. However, it is important to know how the toilet works so that you will not have problems with it.

The first thing that you need to know about toilets is that they are made up of three parts: bowl, tank, and flushing mechanism. The bowl is where you poop, pee, and throw away your paper products such as tissues or sanitary napkins. The tank is where the water goes when you flush the toilet and the flushing mechanism helps remove waste from the bowl and sends it down the drain.

A toilet has two important components:

  • A trapway connects the bowl with the sewer system. Flushing water from the trapway forces waste matter through a pipe that empties into a sewer system or septic tank. The sewer system then carries the waste away from your home or business location.
  • A siphon tube or flapper valve near where you sit on the toilet seat controls how much water flows into the bowl before it can be flushed. When you press down on this lever, water fills up your toilet tank and allows you to flush it.

Determine Why the Toilet Is Running

To fix a toilet that runs, you need to first determine why it is running. Here are a variety of reasons why the toilet may be running.

  • The flapper is stuck in the closed position and is not allowing water to flow out of the tank
  • The flush valve has been turned off, or it has failed to open when you press down on it
  • The fill valve has been turned off, or it has failed to open when you press down on it

How to Fix a Running Toilet


Check Your Flapper

The first thing you should do is check your flapper. A running toilet is usually caused by a faulty flapper. The flapper is a rubber piece that seals off the water inlet as it flows into the toilet tank. It’s responsible for stopping water from flowing backward into the tank after it has been flushed. If this piece isn’t working properly, then water will keep flowing back into the tank even when it’s not being flushed, which will cause your toilet to run constantly.

There are two ways to check whether or not your flapper is working properly:

  • Use a flashlight and inspect the rubber seal around the bottom of the tank for any signs of wear or tear. If there are any cracks or tears in this area, then you should replace them immediately to prevent further damage from occurring.
  • If you don’t want to go through the trouble of replacing your entire toilet, then simply remove all toilet paper from inside the tank and flush one more time before looking inside again. If no clumps remain on top of the water after this final flush, then your flapper is most likely fine and won’t need replacing.

Check Your Fill Tube

If the problem is with your fill tube, then you may need to replace it as well. This tube connects from where water comes into your tank (inside) to where it goes into the bowl (outside). If this tube has been clogged with hair or other debris and doesn’t allow enough water through, then there won’t be any pressure inside your tank, causing your toilet to stop working properly and possibly flooding other parts of your home. The water in the bowl can build up pressure and cause the toilet to explode if you don’t address the problem in a timely manner. If you have a running toilet, check your fill tube first with these steps:

  • Remove the fill tube from the tank by loosening its screw on one end and pulling it out of its housing at the other end.
  • Inspect the tube to make sure it’s not kinked or damaged in any way, then rinse off any debris that may have gotten inside it while you were using it. If there are no obvious problems with the fill tube itself, look for leaks around its connection point to the water supply line or at other joints between components within your toilet system (such as a ballcock).
  • If your fill tube appears to be in good working order after inspecting it with a flashlight, apply penetrating oil such as WD-40 or LPS (liquid plumber’s silicone) to any places where metal surfaces meet rubber ones (such as where fittings attach) and let it sit for about 20 minutes before reinserting into your toilet bowl.

Check Your Float

The float level sensor in your toilet regulates how much water comes into your tank when you flush. If there is not enough water coming into your tank when you flush, then you may have a leak at this point or somewhere else in your system (such as around connections). If you have been experiencing slow flushing for several months and have replaced many parts of your system but still cannot get rid of slow flushing issues, then replacing this sensor could solve your problem permanently. The float valve is the most common cause of running toilets.

The float valve should be replaced if you notice any of these signs:

  • Flooding occurs when you flush the toilet after it has been sitting for some time. This can happen if there’s a leak in your plumbing or if there’s too much pressure in your lines.
  • The tank fills up very quickly after flushing and empties slowly over time.
  • Your toilet doesn’t flush when it should, or it flushes inconsistently or too slowly at times.

Replace Your Fill Valve

A broken fill valve can cause a running toilet as well. To fix this, you’ll need to remove the fill valve from its mount and then remove any debris from inside it before reinstalling it. Then follow these steps:

  • Turn off the water to your toilet tank and flush with toilet paper or something similar until you have cleared all debris out of the tank.
  • Use a screwdriver to unscrew and remove any screws holding down your fill valve (it may be hidden under other parts).
  • Unscrew the fill valve from its mount using a screwdriver or Allen wrench (depending on how many screws there are holding it in place).
  • Look inside and make sure there are no leaks or debris in either side casing; if so, clean them out with soap and water.
  • Reinstall your new fill valve assembly into place.

There’s nothing more irritating than a running toilet. The sound, the smell, and the non-stop running of water — all come together to create your worst nightmare. Knowing how to identify and fix a running toilet is an important skill in the home. A leaking toilet can cause water damage, sewage backups, and an unpleasant smell in your house. The good news is that identifying and fixing a running toilet is easier than you might think with the help of the steps and ways mentioned above.