different types of toilet flush valves and fill valves

Different Types of Toilet Flush Valves and Fill Valves

Toilet flush and fill valves are the mechanisms that regulate the water flow in a toilet. The flush valve flushes the waste by moving the bad water out of the bowl and driving fresh water into the bowl from the tank. Meanwhile, the fill valve refills the tank after the flush by letting water flow into the tank from the water supply line.

Both the valves are vital for controlling the water flow throughout the toilet system. The flush one is found at the cistern’s bottom while the fill one is found atop the cistern.

The types of flush and fill valves are several and each has its own pros and cons. Out of many, the common kinds of flush valves are old-style, dual-style, tower, standard, 3-inch, and 4-inch. And the common kinds of fill valves are ballcock, diaphragm-style ballcock, piston, float cup, and floatless.

Which one will be suitable for you depends on your specific toilet design and needs.

Types of Toilet Flush Valves and Fill Valves [Table]

TypeWorking ComponentUsed In
Old Style Toilet Flush ValveFlapperOlder and residential toilets
Dual Toilet Flush ValveVariousStandard and high-efficiency toilets
Tower Style Flush valveTowerTall toilets
Standard Flush ValveFlapperLow-flow residential toilets
3-inch Flush ValveFlapperLow-flow residential toilets
4-inch Flush ValveFlapperHigh-efficiency commercial toilets
Ballcock-StyleFloat ballOlder toilets
Diaphragm-Type Ballcock Fill ValveDiaphragm, ballLow-flow toilets
Piston-Style Toilet Fill ValvePistonHigh efficiency toilets
Float Cup Fill ValveFloat cupStandard and high-efficiency toilets
Float Less Fill ValveDiaphragm pressure-sensing deviceLow-flow toilets

What Is a Toilet Flush Valve?

A toilet flush valve is a self-closing fitting mechanism that regulates water from the tank flowing through the siphon and rim holes to the bowl. It activates as we press the lever or push button of a cistern.

The device, fixed to cistern’s bottom near the center, comprises-

  • A trip lever
  • Lift rod or chain
  • Flush-valve seat
  • Flapper or float ball
  • An overflow tube

It’s typically made of brass or plastic, chrome, and stainless steel. The size ranges from 2-4 inches.

In most cases, the larger the toilet flush valve is, the faster the water moves, and the better the flush will be.

Different Types of Toilet Flush Valves

Toilet Flush Valves come in different styles and sizes where the common ones are standard flush valves, dual-flush valves, tower flush valves, 3-inch flush valves, and 4-inch flush valves. They feature diverse options such as 360° bowl refill, full or half flushes, reduced water refill, and speed flush.

Here, we’ve divided the types of toilet flush valves into 2 categories: Mechanism-based and Size-based.

3 Types of Mechanism-based Flush Valves

Flush valves use a certain component that brings water from the cistern to the bowl while removing wastewater. Usually, 3 kinds of mechanisms are used in flush valves- the flapper aka the old style, dual style, and tower style. Each of the components operates differently hence the valves are categorized “mechanism-wise”.

The old style has a rubber flap that lifts as you push the button or lever. It’s simple and cost effective but causes clogging troubles and isn’t suitable for solid objects. The dual-style has two flush options, where a full flush works for solid and a partial flush works for liquid, which eventually helps save water and reduce bills. However, it can be quite complicated to install. The tower style has a tower that rises as you flush and releases water into the toilet bowl. It gives quite a quicker flush, however, can be a bit hard to install. 

1. Old Style Toilet Flush Valve

Old style toilet flush valve is typically the flapper-style flush valve which comes in 2 to 4 inches. The mechanism is designed with rubber or neoprene flapper sitting on a hole at the cistern’s bottom. Here, the flapper is linked to a lever on cistern’s top while being held in place with a chain or other linkage.

The flapper seals the opening to the drainpipe when not in use and holds fresh water in the tank. When flushed, it lifts up and lets water move into the bowl. And after the flush, it re-seals the opening and stops the flow.

Because the flappers may not be very strong, we suggest you avoid flushing solids like paper towels or other big stuff. But they are more effective in clearing other wastes like urine or feces. Plus, it’s a must to clean such valves regularly as they can clog easily.

However, the flapper style costs around $5 to $30 depending on the size, design, manufacturer, and other factors. Since many models are cheaper, they can be suitable for the ones with a tight budget. 

Highlighted Features

  • Rubber or neoprene flapper
  • Lever arm
  • Metal or plastic linkage
  • 2 to 4 inches


  • Easy to replace or repair
  • Budget-friendly
  • Flushes our businesses away


  • Not good at clearing solid objects
  • Easy to clog

2. Dual Flush Valve

Dual toilet flush valve is a 2 or 3-inch valve that gives us an option between a “full” or “half” flush to pick from. It’s suitable for both standard and high-efficiency toilets and comes in various designs.

For instance, in some valves, the “full” mechanism is bigger and located higher on the tank, while the “half” is smaller and located lower on the tank. Some valves work with a lever where pushing it up gets us a half flush and pushing it down gets us a full flush. A lot of dual-system valves have a split button, smaller one for half and bigger one for full.

1. Full trigger: It’s used for solid waste disposal. Pressing the mechanism (level or button) opens the valve and lets a large amount of water move into the bowl. Usually, it uses around 1.6 gallons per flush.

2. Half trigger: It’s for disposing of liquid waste. As we push the mechanism, the valve opens and lets smaller amount of water flow into the bowl. It uses around 0.8 to 1.1 gallons per flush.

The dual system is an efficient way to save water since the mechanism can control its flow. Experts say that choosing a novel dual flush valve can reduce water use by 25-50%. But beware, pressing both the buttons at the same time can waste a lot of water which invalidates the purpose of the design. So, make sure to use the button designated for a specific job.

A good dual-style valve can cost you around $20 to $50 because of the updated design. So, it can be pricier than standard ones.

Highlighted Features

  • Two flush modes
  • Reduces water use by up to 50%
  • Handle
  • Used in both standard and high-efficiency toilets


  • Water efficient
  • Reduces water bills
  • Easy to use


  •  Pricier than standard
  • Pressing both the buttons together can waste a lot of water

3. Tower Flush Valve

A tower aka canister flush valve regulates the water flow from tank to bowl with a tall cylindrical tower. It’s attached either on the side of the cistern or over the valve opening with a hole at the tank’s bottom. The valve is mostly used in tall toilets found in commercial buildings.

The tower comes in either metal or plastic. It has a round rubber gasket at the bottom that holds the water in the tank and seals against the opening.

When flushed, the canister lifts up and allows for water to leave the cistern unrestricted. It means the water moves through the hole towards the bowl in 360° without any restriction. As a result, the water flushes waste from all over the bowl more quickly which leads to better and more effective flush.

Highlighted Features

  • Tall cylindrical tower controlling water flow
  • Round rubber gasket
  • Water moves in 360 degrees
  • Used in tall toilets


  • Water efficient
  • Flushes away waste material from any part of the bowl
  • Faster flush


  • Pricier than the standard flush valve
  • Can be hard to install
types of mechanism-based flush valves

3 Types of Size-based Flush Valves

The flush valves mostly come in 3 sizes- the standard or 2 inches, 3 inches, and 4 inches. They mainly differ in diameter size.

The standard flush valve is used in most toilets, hence it’s quite common. Because it’s 2 inches, you’ll find it compact and suitable for most toilet designs. However, it may not be good for flushing solid objects well.

The 3-inch flush valve is larger than the standard and drives more water to flow into the bowl, however, it can use up more water too. The 4-inch flush valve is the largest and gives a strong, effective flush. However, it may consume more water than the other as well.

The importance of flush valve size lies in the impact on flushing performance. The larger the diameter, the stronger and more efficient the flush, and the more the water consumption. 

1. Standard Valve

Standard toilet flush valve is a basic 2-inch valve that uses a flapper or hinged flap for the water flow. It’s connected to a lever or button with a chain or linkage. When we press the handle or button, it pulls on the linkage that lifts up the flapper to push the water into the bowl.  At the same time, it forces the bad water and waste material down at the base of the toilet through an S-shaped tube.

Such a size works on most toilets be it low flow or older models with bigger cisterns.

Highlighted Features

  • 2-inch diameter
  • Flapper or hinged flap
  • Used in low-flow residential toilets


  • Flushes liquids better
  • Available in different types
  • Easy to use


  • Not suitable for solid objects

2. 3-Inch Flush Valve

3-inch flush valves allow more water to move through at a time since their opening is bigger than the standard counterpart. Consequently, we get a more efficient flush which is more useful in disposing of solids. Oftentimes, they use around 1.28 gallons per flush.

The valves are mostly suitable for low-flow residential toilets. They are made of either brass or plastic. Moreover, they come in both single and dual-style models.

Highlighted Features

  • 3-inch diameter
  • More water flow
  • Used in low-flow residential toilets


  • Flushes solids more effectively
  • Available in different types
  • Easy to use


  • Consumes more water than basic ones

3. 4-Inch Flush Valve

4-inch flush valves have way larger openings than most types. They have a piston that lifts up so it lets water vacate the cistern at 360°. Because of the bigger size, it allows for more water flowing out of the tank at once which eventually produces a stronger flush. And consequently, they push the water into the bowl quicker than other counterparts.

4-inch flush valves are very suitable for solid waste material disposal. They are constructed with plastic or brass.

You can find them in both single and dual-style models. They are mostly used in high-efficiency commercial toilets.

Highlighted Features

  • 4-inch diameter
  • Piston controls water flow
  • Flows water at 360 degrees
  • Used in high-efficiency commercial toilets


  • Flushes solids very effectively
  • Available in different types
  • Easy to use


  • Consumes more water than basic ones
types of size-based flush valves

What Is A Toilet Fill Valve?

A toilet fill valve is a mechanism that works to refill the tank with water that flows from the water supply line. When water level goes below a certain level after the flush, the valve opens letting water move into the tank. Once it’s full, the valve closes and stops the flow.

The fill valve is either on the left side of the cistern right near the bottom or atop the cistern. Most models come in plastic while some are metal. The size ranges from 2-4 inches with 2 being the common.

Different Types of Toilet Fill Valves

Toilet Fill Valves also have a variety of styles. The common ones are Diaphragm-Type Ballcock, Piston-style, Float Cup, and Float Less Type Fill Valve. Such types differ in the way they control water level in the cistern.

The Ballcock-style shuts off water flow with a floating ball when the tank gets full. It’s simple and durable but noisy. The Diaphragm-Type Ballcock Fill Valve uses a diaphragm to control water flow and is quieter than the previous style. However, while the plastic diaphragm can’t resist harsh elements effectively, the brass diaphragm’s replacement parts are hard to find.

The piston-style fill valve works with a piston that’s not only easy to maintain but easy to use too. However, it may get loud if the water level goes high.

The fill valves with float cup are suitable for its quiet operation but they might have leak issues. Lastly, the one without floats use electronic sensors which are good at being water efficient but may not be very reliable. 

1. Ballcock-style

The ballcock mechanism has been used for centuries. It includes a stainless steel, copper, or plastic ball attached to the lever arm. This circular object floats on the water inside the tank. It comprises an inlet and outlet valve.

When there’s water pressure, it forces the inlet valve to open letting the water get into the ballcock. The float then opens the outlet valve and lets water move out of the ballcock. As the float lowers, the outlet valve closes while the inlet valve opens. This causes the water to get into the ballcock and lifts up the float.

When the float reaches a certain height, the outlet valve opens and inlet valve closes. This lets water move into the tank and stops as the float reaches the preset point.

Such fill valves wouldn’t wear and clog easily. However, they can waste more water since they don’t have any mechanism to control it. So, it’s better to use such valves for flushing wastes than objects.

These valves have 3 categories:

  • Adjustable ballcock: The one with an adjustable screw that regulates the water level.
  • Non-adjustable ballcock: The one with a fixed position for the float arm.
  • Brass cup ballcock: The one with a cup sitting atop the ball. Such ballcock keeps it from floating high.

When the water level is higher than the threshold, the valve works harder to maintain the level which causes the valve to make noises. However, you can try to adjust the level down a few centimeters to subdue the noise. If that doesn’t help, take an expert’s help.

Highlighted Features

  • Stainless steel, coppers or plastic ball
  • Rod
  • Lever arm
  • Used in older models, low-flow residential toilets


  • Long-lasting
  • Doesn’t clog easily


  • Noisy

2. Diaphragm-Type Ballcock Fill Valve

This kind of toilet fill valve comprises a flexible, pressure-responsive disc namely diaphragm. The diaphragm, made of rubber, makes sure the water level in the cistern is right. It’s located in the valve which stays connected to a float ball or ballcock with a lever. The disc is covered with a bonnet or cap and is triggered by a plastic button.

After flushing, the diaphragm goes down along with the water level inside the cistern that causes the valve to open and let water move out of the supply line. The water flows through the inlet port and opening and gets into the tank. While the tank fills up, the water level rises. And when it reaches a certain level, the diaphragm closes the valve and stops the water flow. 

There’s a check valve too which is a small rubber flap that prevents water from flowing back out of the cistern after the valve closes. It’s made of plastic or rubber and is located in the inlet pipe.

Although the function is somewhat similar, such a fill valve has two categories, material-wise.

Diaphragm-Type Ballcock (Plastic)

The valve is mostly made of a single piece of ABS plastic. The whole design comprises the plastic diaphragm, ball, and inlet valve.

To adjust the amount of water flowing into the cistern, we need to turn the screw at the top of the diaphragm.

It has got a simple construction and ease of maintenance. Because of the material, it’s going to be quite budget-friendly. Then again, the same material can get damaged by minerals and other elements. So, we wouldn’t suggest using this valve if you live in places with hard water.

Highlighted Features

  • Plastic diaphragm
  • Ball
  • Inlet valve
  • Used in low-flow toilets


  • Simple design
  • Affordable


  • Not resistant to harsh elements

Diaphragm-Type Ballcock (Brass)

This valve is made of 2 pieces of cast brass that are clasped with screws. By pieces, we mean body and cover. The body contains metal diaphragm, ball, and lever while the cover protects body and gives a surface so that the inlet valve rests on it.

To adjust the amount of water, we need to bend the brass rod connecting the ballcock to the diaphragm up for more and down for less water.

Brass fill valves can be larger than their plastic counterparts. They have mainly been used in older toilet designs. However, you may still find them in some toilets.

As they have become less common, it can be hard to find replacement parts for the repair job. In that case, contact an expert plumber to help you with that.

Although the button that activates the mechanism is plastic, brass body makes it durable. It’s resistant to both corrosion and other harsh elements. Not just that, a good brass fill valve also requires less maintenance.

Highlighted Features

  • Brass diaphragm
  • Ball
  • Lever
  • Inlet valve
  • Cover
  • Used in low-flow toilets


  • Corrosion resistant
  • Resistant to hard water


  • Hard to fix due to less availability of replacement parts

3. Piston-style Toilet Fill Valve

Piston-style Toilet Fill Valve comes with a plastic or brass piston. This part stays attached to the ballcock that floats up and down depending on the water level.

When the water level goes down after the flush, the fill valve opens and lets fresh water refill the tank. Right after the water reaches a certain preset level, the ball drops and lowers the piston which stops the flow.

Such a valve has either a cast brass body. The metal is more durable than other materials. Not just that, because of having fewer working mechanisms, such valves are easy to use and less likely to wear and clog.

However, the valves can be loud, especially when the water level is extremely high. This causes them to work harder to maintain the level because of which you can hear some noise. In that case, adjusting the water level a few centimeters down can fix the issue. If not, contact a plumber.

Highlighted Features

  • Brass or plastic piston
  • Ballcock
  • Lever arm
  • Used in high-efficiency toilets


  • Less likely to clog or wear
  • Easy to maintain
  • Easy to use


  • Loud when water level is high

4. Float Cup Type Fill Valve

Float cup is considered the modern version of ballcock toilet valve. The design involves a hollow plastic O-shaped cup attached to the valve with a short plastic lever.

The cup here floats up and down responding to the changing water level inside the cistern. When we turn the handle, the level goes up making the cup lift the rod. This opens the water supply valve and lets water move into the tank. As the water level reaches atop, the cup closes the valve and stops the flow.

As the cup is positioned above the water lever, it works to prevent debris from going into the valve. Hence, they won’t clog easily. Plus, the valves aren’t loud because of the same location reason as the water doesn’t need to travel a long way to reach the cup. This reduces the noise that’s created.

However, the valves may need frequent adjustment so that the water level is well-maintained. Moreover, they can be prone to leaks if the cup isn’t properly aligned. In case you end up with leaks, consider using float cup with a leak-proof seal.

Highlighted Features

  • Hollow plastic cup
  • Plastic lever
  • Used in standard and high-efficiency toilets


  • Doesn’t clog
  • Not loud
  • Easy to maintain


  • Require frequent adjustment
  • Can have leaks

5. Floatless Type Fill Valve

Floatless fill valves regulate the water level with a diaphragm pressure-sensing mechanism. They are mounted to the cistern’s bottom and work underwater. Hence, they sense the level depending on pressure. The valves are made of plastic and used mostly in low-flow toilets of the 90s.

Because of the material, the valves are quite budget-friendly. Not just that, they can last long since there are fewer parts that can fail.

However, the pressure sensor can often be inaccurate. This causes regulation issues which makes it less reliable. This is one of the reasons why such fill valve is infamous. Plus, adjusting the level can be tricky unlike the traditional counterparts.

Then again, if it functions fine, the design can be water-efficient.

Highlighted Features

  • Diaphragm pressure-sensing mechanism
  • Used in low-flow toilets.


  • Budget-friendly.
  • Quite long-lasting
  • Can be water-efficient


  • Not very reliable
  • Tricky water-level adjusting system
different types of toilet fill valves

Are Toilet Fill Valves Universal?

No, all toilet fill valves aren’t universal. Most modern models can be compatible with your toilet model, design, or type while some can be incompatible.

For example, many universal fill valves don’t work with dual-style flush toilets. Newer toilets also may not fit into old ballcock style valves.

So, we suggest checking the design of toilet before buying yourself a fill valve.

Following these steps may help:

  1. Check the model number on the sticker or plate on the toilet’s bottom.
  2. Go through the manufacturer’s manual for the toilet. The manual should have all the info about toilet design. It also includes the fill valve type that’s compatible.
  3. Take a plumber or expert’s help as they can suggest a compatible fill valve. You can bring a picture of the toilet to them.
  4. Check the size of fill valves. Some are for taller while some are for shorter toilets.
  5. Pick valve that’ll last long. Make sure the material is of high quality.

How Do I Know What Toilet Fill Valve I Need?

You should know a few things to settle on a toilet fill valve. These are

  • Toilet type: Two are most common- one is gravity-feed and other is pressure-assisted.
  • Fill valve size: It ranges from 2 to 4 inches. Pick one depending on the opening at the toilet’s bottom.
  • Float valve type: Two main types include ballcock and diaphragm. Many designs combine both.

Also, check the measurement of the fill valve height and cistern’s depth. It should help you know the proper size for a fill valve. For this-

  • Measure the fill valve height: from where it connects to the cistern to the top.
  • Measure the depth of the cistern: Start from the internal side of tank’s bottom to the top.

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