Are All Flush Valves the Same Size

Toilet flush valves come in different sizes ranging from 2 to 4 inches, depending on the toilet design. … 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.

How do I know what size flush valve I need?

1. If the opening looks about the size of a baseball or orange, you need a 2″ flapper.
2. If the opening looks about the size of a softball or grapefruit, you need a 3″ flapper.

How are flush valves measured?

The simplest way to determine which Fluidmaster flush valve and flapper to use is to measure the flapper that is already on the flush valve. To identify what size is needed measure the width of the flapper from end to end.