Replace a Toilet Flapper
Stop a running toilet in under 30 minutes by replacing the flapper valve — no plumber, no special tools, parts under $10.
Tools
Materials
- Universal toilet flapper
⚠ Water only — no electricity involved. Towels down before you start.
A toilet that runs constantly almost always has a worn flapper — the rubber seal at the bottom of the tank. Replacing it is the single easiest plumbing fix there is.
Step 1: Turn off the water supply
Find the oval valve on the wall behind the toilet and turn it clockwise until it stops.
Step 2: Drain the tank
Flush and hold the handle down. Sponge out whatever water remains so you can work dry.
Step 3: Remove the old flapper
Unhook the chain from the flush lever arm, then slide the flapper’s ears off the pegs on the overflow tube.
Step 4: Install the new flapper
Seat the new flapper over the valve opening, hook the ears onto the pegs, and clip the chain to the lever arm with about half an inch of slack.
Step 5: Test
Turn the water back on, let the tank fill, and flush twice. The flapper should seal cleanly with no trickling sound after the tank refills.