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ToiletPedia A-Z

Toilet product terminology can be both technical and confusing. We have put together a list of product names and common terms used in the plumbing industry when referring to toilet problems and repair solutions. If you do not find what you are looking for, contact us.

Toilet Terms:

400A - a single fill valve

400C / 400CR – a combination kit that includes a single fill valve (400A) and a flapper (501)

400AK / 400AKR – a complete toilet repair kit that includes a fill valve, flush valve, flapper, tank lever, tank to bowl gasket and all hardware to completely rebuild the inside of your toilet tank.

Rigid Flappers – a product line that have a hard plastic frame above the flapper ball for stronger seal. Fluidmaster Rigid Flappers include:

  • 500 / 501 - a full throttle flapper designed to drain all the water from your tank. Best used with Fluidmaster Flush Valve 507 and all horizontal drain seats. This flapper is best used on toilets that were manufactured before 1994.
  • 502 – a modern flapper for your modern toilet manufactured after Jan. 1994. The water savings flapper ensures proper water usage for 1.6 gallon per flush toilets.

Sure Fit Flappers – All rubber flappers that are designed to fit angled and horizontal flush valves for a more flexible fit. Fluidmaster Sure Fit Flappers include:

  • 503 / 504 / 506 - full throttle flapper designed to drain all the water from your tank. Best used with angled drain seats as well as Fluidmaster Flush Valve 507. This flapper is best used on toilets that were manufactured before 1994.
  • 5051 – a modern flapper for your modern toilet manufactured after Jan. 1994. The water savings flapper ensures proper water usage for 1.6 gallon per flush toilets.

Ballcock – a valve that has a float attached to a long arm

Debris – dirt and or other materials that may enter a fill valve or tank

Captive Cone Washer – a washer that is fitted into a water supply line coupling nut, a specialized washer designed for flexible water supply lines.

Cone Washer – a specific washer in the shape of a small rounded cone designed to be used with straight metal pipes.

Critical Level Mark) (CL) – Critical Level is a reference mark that is required by the plumbing code and is located on the fill valve Hushbody. The  code requires that this mark be 1 inch above the overflow pipe which is part of the flush valve system.

Fill Valve (400A) – a valve that has a float that slides up and down on a vertical shaft Fluidmaster designs include horizontal and vertical valves ( For more detailed information on the Fluidmaster 400 valve please see anatomy of a 400 Fill Valve)

Flushing – Purging dirt and debris from a valve system. Flushing can help maintain the valve system by keeping dirt and other material from staying lodged inside the valve body which can cause valves to fail or slow down.

Flush n Sparkle – the only toilet bowl cleaner that Fluidmaster manufactures and warranties. The system is designed to work without damaging in tank toilet parts.

Flush Valve (507A) – a valve that drains water from a tank. The Fluidmaster flush valve is made up into 3 sections, Overflow Pipe, Drain Seat and Threaded Shank. (For more detailed information on the Fluidmaster Flush Valve please see anatomy of a 507 Flush Valve)

Flapper – a valve that covers the drain seat and seals the tank when not in use. The flapper is actuated by a tank lever and is responsible for regulating water into the bowl for a complete bowl flush.

Gallon per Flush (GPF) - a term that designates how many gallons a flapper can regulate and or how many gallons a toilet can flush for a complete strong flush from the bowl.  Example a toilet from the mid 1970’s will flush 5 gpf; where as a toilet from 1995 is designed to flush 1.6 gpf.

Ghost Flushing – a toilet that refills the tank on its own, also known as phantom flush, toilet cycling and fill valve refill noise. The most common cause is a worn flapper from years of use.

Incomplete Flush – a toilet that will not clear the contents in a bowl after the tank lever has been actuated.  A weak flush where the water in the bowl just spins without leaving the bowl.

Refill Rate – the percentage of water that is directed to the toilet bowl through the refill port / refill tube.

Tank Lever – a toilet handle is both the handle on the outside of the tank and the lever arm on the inside of the tank.  The handle is what lifts a flapper to start the flush.


Anatomy of a 400 Fill Valve System:

Fill valve parts – The 400 fill valve has several moving parts that can be adjusted or replaced. These parts include:

Top Cap Assembly – Located at the top of the valve it is the colored cap and the cap lever arm that connects to a Float Cup Adjusting Rod. The top is a removable part that will allow you access to the valve for repairing and cleaning. The Fluidmaster model numbers for our tops are 350 and 385. (Picture of top(s) needed)

Top Cap Assembly Seal (242) – A small rubber seal located inside the top cap assembly. This seal is what actuates the valve for it’s on and off function. The seal is also a replaceable item and works in most Fluidmaster fill valves systems. The model number is 242

Float Cup Adjusting Rod – Valves that have long rods that extend down from the top cap to a round or square float cup. This rod (a screw or stainless steel sliding link design) allows you to raise or lower the tank water level setting. The current models of Fluidmaster 400 valves use a long rod or screw design that you can turn clockwise and counter clockwise to raise and lower the float cup. The adjusting rod on older 200 & 400 models have a stainless steel link with a spring clip that allows you to slide the float up (more water) or down (less water).  Other model valves with similar designs include 300 and 703 fill valve systems.

Float Cup – a round or square hollow cup located on the Hushbody of a fill valve. The Float Cup is designed to raise the cap lever up with the rising water to a designated point that will turn off the incoming water to the tank.

Hushbody – Model 400 has a removable top half that includes the top cap assembly, float cup and adjustment rod. The 400 valve Hushbody is replaceable with model 400EZI-LS. The Hushbody is secured to the bottom half (Shank) of the fill valve with a Lock Ring.

Lock Ring – A small round ring that is located below the float cup on the Hushbody.  The Lock Ring locks both the Hushbody and Shank together to ensure the valve will not come apart during use. The Lock Ring should only be disengaged when repairing a valve with model 400EZI-LS.

Shank – The bottom half of the valve where the water comes into the tank for refilling.

Shank Thread – the threaded portion of the shank that protrudes from the bottom of the tank, the threaded shank is the area that the fill valve and the water supply line with water supply will connect.

Small Parts – The connecting parts that fit fill valves to the tank; overflow pipe and water supply line. These parts include: Shank & Cone Washer, Fill Valve Locknut, Water Supply Line Coupling Nut, Refill Clip and Refill Tube.

Here is a listing of other parts that may be included in a Fluidmaster Kit:

Leak Sentry - A locking device that is fitted under the float cup and hooks by chain to the tank lever. This locking device locks the float cup in a off position and releases the float only when the tank lever is actuated. This water savings device stops the toilet from turning on to refill the tank when  the tank leaks water into the bowl.

Roller Clamp – Located on the refill tube this clamp controls the amount of water refilling the bowl after a flush. Modern toilets are now using less water to fill the bowl as compared to older toilets. The roller clamp can be used to stop the overfilling of the bowl which wastes water.

Hose Clamps – Located on either end of the Refill Tube that when properly set hold the refill tube to both the refill clip and refill port


Anatomy of a Flush Valve:

Note - It is important to note that Fluidmaster makes a flush valve for toilet tanks that are removable from the bowl, uni-body toilets also known as 1 piece toilets take a different type of flush valve known as Top Mount Flush Valves.

The Fluidmaster flush valve is a single piece that is designed to act as the safety device and drain for the toilet tank. The flush valve is made up of 4 common areas:

Overflow Pipe – The long pipe that extends up above the water. This pipe acts as the safety net so that if a failing ballcock or fill valve continues to fill the overflow of water is directed down the pipe and safely into the toilet bowl.

Drain Seat – Around drain hole that is covered by a flapper so when released drops water directly into the bowl to start a flush.

Flapper – A rubber or plastic plug that covers the hole while the toilet is not in use to seal the water in the tank, also the flapper can regulate the tank water into the bowl for a designated gallon per flush usage.

Threaded Shank – Is the threaded part of the valve that protrudes through the tank hole and is secured to the tank with a large lock nut. Also on the threaded shank is a large gasket known as a Spud Gasket. This gasket is what makes the water tight seal inside the tank after the lock nut has been secured to the thread and tank.

Here is a listing of other parts that may come with a flush valve:

Tank to bowl Gasket – A compression gasket that seals the tank and bowl together. The gasket prevents water from flooding onto the floor once a toilet is flushed.

Overflow Cap – A small cap with a refill port that allows a refill tube to connect to deliver water into the bowl during refill.