How to Replace Toilet Tank Parts

A toilet flapper flush valve on a white background.

The toilet is one of the simplest mechanical items in your home, and one used on a daily basis. With a basic understanding of how it works, you can fix issues that arise on your own, without any special plumbing tools. This guide will help you understand the main parts of a toilet and how to identify and fix common problems.

Flush Lever

A toilet in a white bathroom.

This part of the toilet gets the most abuse. The handle that activates the flushing action of the toilet is probably the most commonly broken moving part of the toilet. The lever is a rod that extends from the handle to a chain that activates the flapper valve.

Several things can go wrong with these handles. This rod used to be made of steel or brass. Of course, when steel sits in a wet place like your toilet tank over a period of years, it begins to deteriorate. Eventually, the rod just corrodes to the point that it breaks. Manufacturers have started making the rods out of plastic, as it's cheaper and doesn't rust. It does, however, break. Whether you find plastic, steel or brass inside your tank, it's pretty common to need to replace your flush lever and handle.

The handle is generally held in place by a nut that is secured against the wall of the tank. It should be located at the place where the handle comes in from outside of the tank. This nut can be loosened with your adjustable wrench. Once the nut has been removed, the handle can slide right out through the hole in the tank wall. Slide the new one in and tighten the nut back into place.

TIP: Our plumbing consultant, Mark Vander Sande, reminds you, “The nuts that hold the handle on are usually reverse threads. So loosen like you would tighten.”

Flapper Valve

A toilet surrounded by plumbing tools.

The flapper valve is the mechanism inside your toilet tank that controls the flush. When you push on the handle, the lever lifts a chain that in turn, lifts the flapper valve. The valve covers an opening in the bottom of the tank that allows the water to flow down into the bowl and creates the flushing action.

This valve is usually made of rubber, which can become hard and brittle over time. Issues arise if it doesn't seal correctly over the opening at the bottom of the tank and water seeps down into the bowl. The problem is usually identified by your toilet running non-stop. The tank keeps trying to fill itself unsuccessfully because all of the water is leaking around the edge of the valve.

In order to change the valve, you first need to empty the tank of water so that you can work. Find the shut-off valve located on the water line that supplies your toilet. Turn it off, and then flush the toilet one time. The tank should empty as normal with the flush, but will not refill.

There are several different styles of flapper valves, and the best way to ensure that you get the right one is to remove it and take it with you to the store. Install the new one into the clips that held the old valve in place, and then turn the water supply back on. It should be as good as new.

TIP: Mark says, “Check the flush valve, the part where the flapper rests to seal. Remove any debris that may be stuck there.”

Float System

A door opens to a toilet.

The float system controls how much water comes into the tank. When you flush, all the water in the tank rushes down into the bowl, leaving the tank empty. As the tank empties itself, a switch is activated by the float as it falls with the water level. That switch opens a valve, which begins to refill the tank. As the tank refills with water, the float begins to rise. When it reaches the appropriate level, shut the valve off.

Like the problem with the flapper valve, a defective float switch will cause the toilet to sound like it is running constantly. The way to differentiate between the two problems is to take a look inside the tank. There should be a long hollow pipe standing next to the float mechanism. If the water level is so high that the excess is pouring down that overflow pipe, then your float switch isn't working. It means that your toilet is endlessly filling itself and the excess water is running down the overflow pipe and into the toilet bowl.

To replace the float system, drain the tank the same way as when changing the flapper valve. Once the tank is empty, you will find a large nut at the base of the float system. Loosen that nut and remove the entire float system.

TIP: Mark suggests, “Have a small bucket or a rag on the floor beneath where the float system is being removed. A small amount of water will always drip out when you remove this device. Or take a sponge and get the rest of the water out of the tank.”

Keep in mind that, on some models, the flapper valve is integrated into the float system structure. If this is the case, then the float rod should be able to be removed by itself.

As with the flapper valve, there are several different styles available, and the best way to ensure that you get what you need is to take the old one with you to the store. The new one can be installed in the same way the old one came out. Make sure that you tighten the nut securely, but don't over tighten. The plastic used to make the float systems can crack fairly easily.

These are the most common problems you will encounter inside your toilet tank. Take the time to identify the problem correctly, and you should have no problem replacing these parts. They are all easy to get to and do not require any special tools to get the job done right.

Mark Vander Sande, a professional plumber, contributed to this article.