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No item in the American household is more ubiquitous than the modern commode or toilet. Perhaps no one item must be more immediately repaired if made non-functional to keep the home habitable. We will be identifying the 11 most common toilet tank parts. Should the need ever arise, you will be able to diagnose the problem with your toilet, identify the part requiring placement, and proceed with the required repairs – thus saving time, money and aggravation.A plumber showing up to replace just one or two toilet tank parts will cost you at least $$. The price of those toilet tank parts could be as little as a few dollars. Having a plumber show up to replace those same parts at night, on weekends, or holidays, you can expect that price to double.

How Toilets Work

The operation of a toilet is somehow simple, yet complex. The function of the bowl, tank, flanges, fillers, rings, nuts, and levers work in unison to create the swirl and the flush to sweep waste from your house. The typical flush cycle actually works something like this:

There are two main parts to a toilet, the bowl which sits above the drain-siphon and the tank reservoir which sits above the bowl and refills it. The tank reservoir is replenished by the fill valve and houses most of the mechanical parts of the toilet. Therefore, when problems occur, most often the cause lies within the parts in the tank.

One thing to keep in mind is that the actual toilet tank parts will vary in different commodes and new parts may have different designs incorporated into them. Regardless, there is enough commonality and interchangeability that repairs with different parts than original are possible and even commonplace.

The flush cycle starts with pushing the flush lever which is mounted on the reservoir. This pulls the chain attached to the flapper valve and gravity causes the water in the tank to flow through the siphon and through the rim holes and into the bowl flushing away the waste. The mass of the water leaving the tank is sufficient, that as it travels the S-bend, it creates a siphon which evacuates the contents of the bowl into the main drain.As the water in the tank leaves, the float valve inside falls, activating the fill valve which opens to let pressurized water back into the reservoir tank. The flapper valve then falls back to the bottom closing the valve. As the water level moves back, the fill valve switches off and the cycle is complete and ready to repeat as necessary. 

water level moves back, the fill valve switches off and the cycle is complete and ready to repeat as necessary.

11 Toilet Tank Parts You Should Know About

working-man illustration

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1. Flapper valve

The flapper is the barrier between the siphon and bowl and the reservoir tank. It is activated by the flush lever pulling the metal chain attached to it.

2. Flush Valve Seat

The flapper valve sits in this seat which provides a seal so that water does not leak from the tank past the flapper valve.

3. Flush Lever

The flush lever is what activates the flush cycle by being depressed and pulling the metal chain which pulls the flapper valve away from the flush valve seat, allowing water to rush by.

4. Metal Ch​​​​​ain

This lightweight metallic chain connects the flush lever to the flapper valve.

5. Fill V​​​​​alve

The fill valve has a plastic float surrounding it filled with air and as the water leaves the reservoir, the buoyant float drops down the body of the fill valve activating the valve which is under pressure. As the reservoir tank fills, the plastic float returns toward the top and then disengages the fill valve cutting off the flow when the proper water level is reached.

6. Refill Tube

This tube travels from the fill valve to the overflow tube.

7. Refill Tube Clip

The refill tube clip is attached to the refill tube and clips it in place on the overflow tube.

8. Overflow Tube

The overflow tube serves as an open drain pipe should anything go wrong in the tank which would lead to an overfill situation and drains any water above the overflow tube directly away.

9. Float

The float, as mentioned above, surrounds the fill valve but older styles of the ball variety simply had an arm attached to the valve which would allow it to travel up and down with the water to engage and disengage the valve.

10. Flush Valve Seat Nut

The flush valve threading extends through a hole in the bottom of the reservoir tank. The flush valve seat nut engages those threads to hold it in place. This is covered by the sponge gasket on the exterior of the tank to provide a seal between the reservoir tank and the bowl.

11. Fill Valve Nut

The fill valve thread also extends through the body of the reservoir tank and the fill valve nut holds the fill valve in place.

Common Problems and Repairs

Doubtlessly, the most common toilet tank part needing repair is the continuously running fill valve. Fortunately, there are only a few conditions that can cause this and they are all easily fixed unless caused by a crack in the tank. This is something you would likely have already noticed. The fix is to determine where and why there is a leak. If the fill valve nut is loose or the valve seat nut is loose, repair is possible with simple tightening. However, if there is a defect or crack in the reservoir tank or the toilet bowl, replacement may be your only option.The next most likely toilet tank part to repair is the ball float if your toilet has one. Ball floats are an older style of installation but are still in common use, though you can elect to replace a ball float and fill valve with the newer, single piece style with no problem. Repairs directly to the ball float can be quick and easy. Simply bend the float arm down to adjust the cutoff level to below the height of the overflow tube. When you first open the lid of the tank, if you see water pouring through the overflow tube, adjusting the ball float will often fix it. You should make sure the ball float is in good condition and has no leaks.


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If you do not have the ball type float and instead have a standard fill valve and water is pouring into the overfill valve, you can adjust the level of the water below the level of the overflow tube by turning the adjustment knob or screw counterclockwise until the water drops to the desired level.If the above does not work, it is advisable to replace the fill valve unit. You must turn off the water to the tank and open the flapper valve to get rid of the water. Any remaining water will have to be sponged out or removed with a wet vac. Disconnect the water supply to the fill valve using channel wrenches to loosen and remove the fill valve nut and float assembly and replace it.The second most common problem regarding toilet tank parts concerns the flapper valve. If there is no water pouring over the overflow tube, the most likely culprit is the flapper valve. The flapper valve is attached to the overflow tube and you may be able to detect water leaking past it.

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Sometimes, merely readjusting the valve will allow it to reseat, stop the leak, and trigger the shutoff of the fill valve. If not, you can replace the flapper by turning off the water, disconnecting the chain, and prying back the plastic or rubber arms which hold it to the hinge lugs on each side of the overflow tube and replacing it with your new flapper valve. Then just reconnect the chain and turn the water back on.When replacing the flapper valve, you will notice it sits in the flush valve seat. Examine the seat and make sure there are no cracks and no erosion has taken place. If the valve seat is eroded or cracked, you will want to replace it. To replace the flush valve seat, the water to the tank must be turned off, and all water removed.The tank mounting bolts must be removed, and the tank unmounted from the toilet. The old sponge gasket covering the flush valve seat nut should be replaced at this time, too. Just remove it and loosen the flush valve seat nut to replace the valve seat. Follow the directions with your hardware kit to the letter as not each kit is the same.


So now you have some valuable knowledge about how a toilet works. You also have a list of toilet tank parts and some guidance in the unfortunate event of a toilet not working properly. We encourage you to remember these toilet tank parts, as they are all essential to the proper functioning of a toilet. We hope this information will be useful and it will give you the confidence necessary to handle this minor home repair – thereby saving you time, effort, and aggravation.


Featured Image via Pixabay

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