Skip to Content

5 Different Types of Toilet Fill Valves

A collage of toilet fill valves.

General Toilet Upkeep and Maintenance

If there’s one thing I’ve learned in life, it’s always to keep my toilet in good working order. And let me tell you, nothing is more embarrassing than having a clogged toilet when a company comes over.

You never know when you might have guests over, and they’ll need to use the facilities. Fortunately, I’ve developed a few tricks for maintaining my toilet properly. For example, I always make sure to use the right brand of toilet paper so that there’s less chance of anything getting backed up.

I also try to avoid flushing anything other than waste and paper products – no feminine hygiene products or baby wipes, for example. It can help to hang a reminder somewhere within the eyeshot of any bathroom goers. 

Of course, my toilet sometimes gets clogged even with all of my precautions. 

Still, one of the simplest things you can do to keep a bathroom in good working order is to ensure your toilet valve is replaced and properly fitted as needed.

Related: Top 15 Toilet Brands | Online Toilet Stores | Types of Toilet Seat | Types of Sink Shut Off Valves

When to Replace Your Toilet Fill Valve

A man holding a plumbing tool and fill valve.

Over time, toilet fill valves will begin to wear out. This normal wear and tear is due to the components’ constant movement and exposure to the water in the tank. As a result, it’s important to be familiar with the two common symptoms of a failing toilet fill valve:

  1. The toilet takes a long time to fill. One common symptom is when the toilet takes longer to fill up after being flushed. This extended fill time is because the valve can no longer open fully, reducing the water flow into the toilet tank. If you notice this symptom, it’s probably a good time to replace your toilet fill valve.
  2. The toilet is leaking. Another sign is leaking around the base of the toilet. Leaking is usually caused by worn-out seals, which can no longer prevent the water in the tank from escaping. Any leaking will cause your toilet to fill with water more frequently. If you hear the tank filling at regular intervals even when it’s not in use, that’s a tell-tale sign that you need to check your toilet fill valve and possibly replace it. 

Fortunately, replacing your toilet fill valve is one of the least expensive plumbing projects you can be faced with. 

Types of Toilet Fill Valves

Common types of toilet fill valves include:

  • The float cup fill valve.
  • The diaphragm fill valve.
  • The ballcock fill valve.
  • The piston fill valve.

All types of valves are designed to prevent water from overflowing from the tank and into the bowl. However, each type has its own advantages and disadvantages.

Illustration of flushing mechanism with label.

1. Flapper-style Toilet Fill Valve

Flapper-style Toilet Fill Valve uses a rubber flapper to seal the opening at the bottom of the tank. When the handle is turned, the flapper lifts and allows water to flow into the bowl. 

Flapper-style fill valves are the most common type of valve used in toilets today. Less expensive than other types of valves, they are relatively simple to install and operate and provide a good seal against water leakage.

If you’re looking for a simple, easy-to-install valve that provides a good seal against water leakage, then the flapper-style valve is a good choice. However, they can be susceptible to clogging from mineral deposits and may require occasional adjustments to maintain proper water levels. 

Next, we’ll take a look at the float-type fill valve.

2. The Float Cup Fill Valve

An old float ball of a toilet fill valve.

The float cup fill valve is another very common type of fill valve used in toilets. Float-type fill valves are similar to flapper-style valves, but they use a float instead of a flapper to control the flow of water into the toilet bowl.

The cup-shaped float rises and falls with the water level in the tank. When the handle is turned, the water level increases and the float cup lifts a rod that opens the water supply valve and allows water to flow into the tank.

When the water level reaches the top of the cup, the float cup closes the water supply valve and shuts off the water flow. The float cup valves are less likely to clog than the flapper-style valves, but they may require more frequent adjustment to maintain the proper water level.

3. The Diaphragm Fill Valve

The diaphragm fill valve is similar to the float cup fill valve but uses a rubber diaphragm instead of a float cup. The diaphragm is connected to a rod that opens and closes the water supply valve.

As the water level in the tank rises, the diaphragm lifts the rod and opens the water supply valve. When the water level reaches the top of the diaphragm, it pushes down on the rod and closes the water supply valve. 

Diaphragm-style fill valves are the least common type of valve used in toilets, but they offer some distinct advantages over other types of valves. They are very resistant to clogging from mineral deposits and provide an excellent seal against water leakage.

However, they can be more difficult to install and may require special tools for proper maintenance.  Diaphragm-type fill valves are the most expensive type of valve, but they offer the best seal against water leakage.

They are also less likely to clog than other valves, but they may require more frequent adjustments than others. But if you’re looking for a valve that provides an excellent seal against water leakage but can be more difficult to install and maintain, then the diaphragm-style valve might be the better choice.

Diaphragm-style valves are typically used in older model toilets.

4. The Ballcock Fill Valve

A ballcock fill valve on a container.

In a toilet, the ballcock fill valve is a type of fill valve that uses a floating ball to control the flow of water into the tank. The ballcock has an inlet valve and an outlet valve. The inlet valve is opened by the water pressure, allowing water to enter the ballcock.

The float opens the outlet valve and allows water to exit the ballcock. When the float is lowered, the outlet valve is closed, and the inlet valve is opened. This allows water to enter the ballcock and raise the float.

When the float reaches a certain height, the outlet valve is opened, and the inlet valve is closed. This allows water to flow into the toilet tank and stop when the float reaches its highest point. 

Ballcock fill valves are available in different sizes and types

The most common types of ballcock toilet fill valves are: 

  • Adjustable ballcock – Adjustable ballcocks have an adjusting screw that controls the water level in the tank.
  • Non-adjustable ballcock – Non-adjustable ballcocks have a fixed position for the float arm.
  • Brass cup ballcock – Brass cup ballcocks have a cup that sits on top of the float ball and prevents it from floating too high. 

These ballcock fill valves are most often seen on older model toilets, but there might be other reasons for selecting this type of fill valve for your toilet, such as needing an adjustable toilet fill valve. 

5. Piston-style Toilet Fill Valve

A person fixing toilet fill valve.

Finally, we’ll look at the piston-style fill valve, which functions in a similar manner as the ballcock toilet fill valves described above. Piston-style fill valves are less common than others, but they offer some advantages over their counterparts. 

They are less likely to clog from mineral deposits and provide a more positive seal against water leakage. If you’re looking for a valve that is less likely to clog and requires less maintenance, then the piston-style valve might be a solid option.

However, they can be more challenging to install and may require regular maintenance. 

Check Plumbing Codes for Updates

One important consideration is that, according to new plumbing code requirements, anti-siphoning capabilities are now required for some toilet fill valves.

This new requirement means that any new plumbing installation must have a mechanism in place that will prevent dirty water from backing up into other water sources in the event of a natural disaster or burst pipe.

Installations that don’t meet this new requirement can result in contaminated drinking water, so it’s essential to be aware of the changes to the code.

So, which type of toilet fill valve is right for you? The answer depends on your needs and preferences.

Consideration When Selecting a Toilet Fill Valve

A few questions you may want to ask yourself as you make your final selection: 

Is it easy to install?

Replacing your toilet fill valve is an easy DIY project and typically does not require a plumber. Your fill valve kit will come with an easy-to-follow installation guide. 

Is it durable? 

High-quality plastic and rubber valves will last longer than the metal variety, which can easily rust.

Will it work with your water pressure?

If you have a low-pressure toilet, make sure you select the correct valve for the best performance. 

Is it water-conserving? Is it noisy?

You may also want to look for water-saving fill valves; if it’s an issue, some purport to be quieter than others. No matter which type of valve you choose, be sure to follow the manufacturer’s instructions for installation and operation.

Just about any toilet fill valve you buy will come in what is referred to as a “kit”, though this is somewhat misleading as it most likely will NOT include tools you might need to complete the installation. That said, all toilet fill valve replacement kits do come with a set of instructions that you can follow to get the job done yourself.

However, if you have any additional questions, or if you find yourself struggling with the project, in that case, contacting a qualified plumbing professional might be worth your time.