How to Replace a Toilet Flapper

Overview

The toilet flapper is the rubber seal at the bottom of the tank that lifts when you flush and seals the water in between flushes. It's the #1 cause of running toilets and the easiest plumbing fix in existence.

Flappers degrade over time — they warp, crack, or get mineral buildup that prevents a proper seal. When this happens, water constantly leaks from the tank into the bowl, causing the fill valve to run periodically.

Replacement takes 5 minutes, costs under $8, requires zero tools, and saves you $50-100 in wasted water per month. There is literally no reason to call a plumber for this.

Tools Needed

• None required

Materials Needed

• Universal toilet flapper — $5-8

Step-by-Step Instructions

1. Turn off water and flush: Turn the shut-off valve behind the toilet clockwise to stop water flow. Flush the toilet to empty the tank. You don't need to get every last drop out — just most of it.
2. Remove the old flapper: The flapper hooks onto two pegs (ears) on the sides of the overflow tube. Simply unhook it from both sides. Disconnect the chain from the flush lever. The whole thing comes out in 5 seconds. If your flapper has a ring that slides over the overflow tube instead of ears, you'll need to remove the tube (more involved but still doable).
3. Install the new flapper: Hook the new flapper onto the same two pegs on the overflow tube. Connect the chain to the flush lever, adjusting so there's about 1/2 inch of slack in the chain when the flapper is closed. Too much slack = weak flush. Too little = flapper can't seal. Turn the water back on, let the tank fill, and flush a few times to test.

When to Call a Professional

You almost never need a plumber for a flapper. However, if the flush valve seat (the ring the flapper seals against) is pitted, corroded, or cracked, the new flapper won't seal properly. In that case, the entire flush valve needs replacing, which is a bigger job.

Related Repairs

• fix running toilet
• unclog drain
• fix leaky faucet