Toilet Flush Valve Types and Sizes

A flush valve is the part inside the tank of a toilet that moves the water into the bowl. Toilet flush valves come in different sizes ranging from 2 to 4 inches, depending on the toilet design. If you are thinking of buying a new toilet, pay attention to the type of flush valve it has. In most cases, larger valves move water faster, resulting in a better flush.

When replacing the flush valve in an existing toilet, make sure you get a valve that will work for that specific toilet. Typically, you have to stick to the size that is in there already. If you happen to find that the flush valve is an uncommon size, such as 3.5 inches, try contacting the toilet manufacturer for a replacement valve. They may end up sending you a new flush valve for free.

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    Standard Flush Valve

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    Most toilets have a standard flush valve. This is just a basic 2-inch flush valve and flapper that lifts up when you push the toilet handle down. Standard flush valves may be found on low-flow toilets and on some older toilets with large tanks. Changing a flush valve in a standard toilet is a fairly easy project that can be done by most homeowners. If you have a running toilet and have replaced the flapper, but this did not stop water from leaking out of the tank, your toilet may need a new flush valve.

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    3-Inch Flush Valve

    Having a larger flush valve means getting the water into the bowl and down the drain more quickly. The difference in flushing power between a 2-inch and a 3-inch flush valve can be substantial, and the larger valve can produce a better flush with much less water. There are some great toilets using only 1.28 gallons per flush with a 3-inch flush valve. Replacing a 3-inch valve is the same as replacing the standard flush valve; it is just a larger valve. Several manufacturers offer 3-inch universal flush valves that should work well.

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    Tower-Style 3-Inch Flush Valve

    Like the 3-inch flapper-style flush valve, the 3-inch tower flush valve has a 3-inch opening in the tank where the water goes into the bowl. But while a flapper partially obstructs the valve opening, the tower-style valve allows for water to leave the tank unrestricted (360-degree flow), which can produce a faster flush. Changing a tower style flush valve seal can be as easy as changing a flapper.

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    4-Inch Flush Valve

    The 4-inch flush valve is the largest of the flush valves and typically includes a piston that moves up to let water evacuate the tank at 360 degrees. This type of flush valve delivers the water into the bowl faster than any other type of valve, producing great flushing power with very little use of water.

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    Dual-Flush Valve

    A dual-flush valve gives you the option of a half flush and a full flush with the same valve. Some dual-flush valves are operated with a handle; you get a half flush when the handle is pushed up and a full flush when the handle is pushed down. Other dual-flush valves work with a double button; one button triggers a half flush, the other a full flush. There are also dual-flush valves that are made specifically to convert a normal toilet into a water-saving toilet. Installing and using a dual-flush valve can provide significant water savings every year.