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Toilet Troubleshooting 101

We are happy to provide you with the following general toilet information. While there are MANY different types, styles and models of toilets (many of them requiring unique parts made by the toilet manufacturers specifically for their toilets), we're sure the information we offer below will provide a few simple tips for the troubleshooting and repair of some of the most common toilets out there. For information to help fix a leaking toilet, click here.

Constant Running Toilet - General Trouble-Shooting

The most common type of toilet, especially in homes, consists of a tank and a bowl, whether in two separate pieces or a single molded unit. However, some toilets don't have a tank, but instead have a large, exposed flushing mechanism often referred to as a flushometer (such as those made by Sloan or Delany). Flushometers come up from the toilet bowl and back into the wall and can either be concealed inside the wall entirely, or exposed.

(Flushometer-type toilets are more common in commercial applications, such as restaurants, department stores, & stadiums but can sometimes be found in homes as well. Repairing this type of flush valve is often unique to the manufacturer of the valve, as the internal parts (and causes of their problems) do vary. If you are trying to repair a flushometer valve, it is best to first consult with the manufacturer so that they can help you trouble-shoot the problem and determine the best way to repair it. We do carry many parts for Delany flush valves, as well as many parts for Sloan flush valves.)

If your toilet has a tank, then there are generally three main culprits that will cause a "running" toilet (water runs when the toilet is not in use):
  • Problems with the flush valve
  • Problems with the fill valve
  • Loose flush lever assembly
It is usually easy enough to determine if any of these are the issue by looking inside the tank and then flushing the toilet. Take special care when you remove your tank lid because they are extremely fragile, can be heavy and are usually slippery when wet.

Let the water exit into the bowl and wait for the tank to refill. If the flapper (or flush ball) does not stop the water from exiting from the tank into the bowl by properly seating back down into the flush valve, then the problem is likely your flapper/flush-ball, your flush-valve assembly, or a loose flush lever assembly.

If the flapper/flush ball seals the flush valve successfully but water is still continuously filling into the tank (and subsequently into the bowl through the toilet tanks overflow tube), then the problem could be that your fill valve is allowing your tank to overfill with water.

Checking the Trip Lever & the Flush Assembly
When water is passing the flush valve & is continuously running into the bowl

The best place to begin, because it is the easiest to fix, is with the flush lever (also called a "trip lever"). Is it tightly secured to the wall of the tank? If not, try reaching into the tank and tightening the lock nut to be sure (hand tightening is ok and prevents the
trip lever
possibility of cracking your china/porcelain). A flush lever lock-nut usually tightens opposite from standard nuts, so reach in and turn the nut from right to left. Make sure the parts of the flush valve lever are intact and are not bending or coming apart from each other. If the flush lever appears to be in bad shape, you may just need to replace it with a new flush lever assembly.

If the flush lever appears to be in good working order, then the next area to check would be your flapper/flush ball and the flush valve. When replacing or repairing the flush valve and its parts, make sure to turn the water to your toilet off. The shut-off valve is typically located behind the toilet.

First, check the rim of the flush valve where the flapper/flush-ball rests to seal the water in the tank. Is it smooth, or are there chips or rough spots? A rough or chipped flush valve can certainly cause your toilet to run and should be replaced if the rim has been compromised. If the rim of the flush valve appears to be nice and smooth but water is still passing the flapper/flush ball and flowing into the bowl, then a bad flapper/flush ball is likely the cause of the problem.

replacement toilet flapper
A bad flapper/flush-ball (possibly cracked) can fill with water when the tank is emptying causing the flapper/flush-ball to close prematurely. They can also become misshapen or deteriorated, preventing the necessary seal and allowing water to pass through to the bowl. There are many different types of flappers and flush balls, so the method of repair will vary from toilet to toilet. If your toilet has a flapper that attaches to a flush lever arm/rod by a chain, it's important to make sure the chain isn't too tight or too loose. If the chain is too tight, the flapper will allow water to run into the bowl because it can't seal
itself sufficiently onto the rim to the flush valve. If the chain is too loose, the flapper won't be pulled up enough to stay open, thus not allowing the water to flush into the tank. The chain should have just a slight bit of slack in it, typically around a half-inch.

If the trouble you are experiencing is the periodic sound of water filling your toilet tank (often accompanies by the sound of trickling water in the toilet), then you most likely have water exiting the tank and entering the bowl. The most common cause of this problem is the flapper/flush ball. When your flapper/flush ball is going bad, it won't seal well and can allow water to seep past slowly; when the water level reaches a certain level, the fill valve will kick on and refill the tank to a level that shuts it back off. It is also important to check the condition of your flush valve and your flush lever as noted above, as they can also be responsible for a slow leak.

Checking the Fill Valve
When the flush valve is sealed properly but water continues to fill the tank
and exit into the bowl through the overflow tube

fill valve
Toilet tanks have an overflow tube to prevent water from spilling over the top of the tank and onto the floor, but a fill valve is designed to shut off the water flow (when the toilet tank is full) to prevent the tank from over-filling (thus not allowing water to continuously exit the tank and into the bowl through the overflow tube). If your fill valve is not shutting off the water once the tank is sufficiently full, the problem may be with your toilet fill valve. This could be caused by dirt or debris in the valve, or it may be the fill valve needs to be repaired or replaced.

To inspect the fill valve to see if it can be repaired, you must first turn off the water. The shut-off valve can usually be found behind the toilet. If you have the type of fill valve that uses a float ball (which closes the valve when it rises) then first check and make sure the float ball doesn't have any cracks in it. If a float ball has water inside of it, it could be too heavy for the fill valve to lift in order to shut off the incoming water, causing the toilet to constantly run. It is also a good idea to make sure the float ball and rod aren't sticking, in which case you would most likely need to repair or replace the fill valve).

There are also fill valves that do not use a conventional float ball to shut off the valve. Instead, they are canister-type fill valves (such as the Fluidmaster #400A) which have a chamber that rises up the body of the fill valve to shut off the water supply. Over time, this type of float chamber can stick. If you are unable to stop it from sticking, then you should either repair or replace the valve.

Check the internal seals of your flush valve to make sure they are in good shape. If they're ripped or disintegrating, you can try to locate replacement parts for your fill valve. Please note that not all fill valves are the same and are manufactured by different companies. Make sure to order repair parts for your specific valve.

To check for dirt/debris, you can try removing the top cap from the fill valve (if your fill valve has a cap that can be removed) and the loose washers and parts from the inside of the valve. Look at the seals to confirm they are in good shape. Make sure to take notice of how you removed the parts so that you will be able to replace them later. Grab a plastic cup or similar vessel, place it directly over the center of the fill valve, and then slowly and carefully turn the water back on (low); the water will flow out through the center of the fill valve and should remove any debris from inside the valve. Next, turn the water back off so that you can re-install your fill valve parts and seals. Re-install the top assembly and turn the water back on. If the fill valve shuts off when the tank is full, then it would appear the problem has been fixed.

If you have replaced the flapper or flush ball (or determined the flapper/flush ball & flush lever are not the problem) and/or your attempt at repairing your fill valve was unsuccessful, you will most likely need to purchase a new fill valve. Pay careful attention to the type of fill valve that is used in your toilet, as again, some toilets require unique components that the manufacturer made specifically for their toilet models. It may be a good idea to contact the manufacturer of your toilet for their repair advice as well.

Occasional Running Toilet - General Trouble-Shooting

If you hear water turn on in your toilet, run for a few seconds and then shut off when no one has been using the toilet, you most likely have an occasional running toilet. This should not be confused with a ghost in the house.

If you have a two-piece toilet, this type of problem can be caused by worn out gaskets inside of the tank. The flush valve seal, or the tank to bowl bolt washers wear out over time and either deteriorate or harden and crack causing the tank to leak very slowly.
Toilet tank gasket
This is why it can take a while for enough water to leak out of the tank, causing the float to drop, and turn the fill valve on to refill the tank. Unfortunately, to replace these seals or washers, you will need to disassemble the toilet tank from the toilet bowl.

These types of leaks can be difficult to pinpoint since the water can leak out of the tank and onto the bowl portion hidden by the tank. All bowls are unintentionally made slightly different due to how porcelain is manufactured. One bowl may have a low side towards the front of the bowl inlet hole, and another bowl may have a low side towards the back of the bowl inlet hole, or another one may have the low side on one of the sides of the bowl inlet hole. Water will naturally flow to the lowest point. Adding food coloring to the inside of the tank can help you determine where the leak is actually occurring.

When replacing a faulty seal beneath the flush valve, make sure to turn the water to your toilet off. The shut-off valve is typically located behind the toilet. At this point, since you will be taking the tank off of the bowl, you should also replace the tank to bowl bolts and washers and also the tank to bowl gasket. The tank to bowl gasket is located between the tank and bowl and fits over and/or around the bottom of the flush valve.

Please note: The information provided above is GENERAL information only and is intended to address the common problems with most toilets that do not use manufacturer-specific parts. We provide this information to assist with simple toilet repairs. If you are uncertain of the type of parts your toilet requires, we strongly recommend you contact the manufacturer of your toilet or perhaps consult with a local plumber for their professional advice.

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