TOTO 3-inch Replacement Flapper THU500S — OEM-Compatible Toilet Flapper with Chain & Rubber Seal

The TOTO Replacement Flapper THU500S is a 3-inch polypropylene flapper with a rubber sealing surface and chain, made to replace select TOTO 3" flush valve flappers for reliable tank sealing and straightforward installation.

This flapper is engineered to fit a range of TOTO 3-inch flush-valve toilet tanks and provides a direct, OEM-compatible replacement for many older or worn flapper parts. The body is molded from durable polypropylene while the sealing lip is rubber to form a water-tight seal. The part includes a length of chain and model-specific setup instructions so you can match the flapper lift and chain length to your particular TOTO tank.

Which TOTO models and part numbers does this flapper replace?

The THU500S is intended as a replacement for multiple legacy TOTO 3-inch flapper part numbers, making it a convenient single-stock solution for service and repairs. Check your original flapper part number or tank model to confirm compatibility before purchase.

• Replaces THU138S, THU140S, THU175S, THU253S, THU275S, THU277S, and THU299S
• Also fits THU331S, THU332S, THU347S, THU369S, and THU499S
• Designed for TOTO 3" flush valve tanks only—verify valve diameter

How do I install and adjust the TOTO THU500S flapper?

Installation is straightforward and requires no special tools: remove the old flapper, hang the new flapper on the flush-valve pegs, and connect the chain to the flush lever. The included instructions outline chain length and lift settings that match several TOTO tank designs. Small chain adjustments change the lift height and sealing action to eliminate run-on or partial flushes.

• Includes chain and model-specific setup instructions
• Hang on the flush valve ears and hook chain to lever arm
• Adjust chain slack for full seal without excess tension

What are the materials and performance features of this flapper?

The flapper combines a rigid polypropylene body with a resilient rubber sealing surface to balance structural strength and leak-free performance. The rubber lip conforms to the flush valve seat to reduce slow leaks, while the polypropylene resists warping from tank water. It’s built to be a like-for-like replacement for TOTO 3-inch flappers so you retain the original tank operation characteristics.

• Polypropylene construction for dimensional stability
• Rubber seal for watertight contact on the 3" seat
• Factory-supplied chain for correct lever engagement

Will this flapper affect my toilet’s water consumption?

The flapper itself does not change your toilet’s designed flush volume; it restores intended sealing and lift behavior so the tank delivers the original flush volume. Replacing a worn or leaking flapper can stop phantom tank refills and eliminate wasted water, returning your toilet to its designed performance. For dual-flush or specialized low-consumption models, confirm compatibility with the manufacturer’s guidance.

• Does not alter factory flush volume—restores proper function
• Stops leaks that cause unnecessary water use
• Compatible only with specified TOTO 3" flush valve tanks

Who is this for: The TOTO THU500S replacement flapper is intended for homeowners, plumbers, and maintenance personnel who need a direct, durable replacement for select TOTO 3-inch flush valve tanks. It’s a practical choice when servicing older TOTO toilets or when multiple legacy flapper part numbers must be supported from a single, reliable replacement unit.