Tools & materials
- Replacement flapper (match your flush valve size, usually 2 or 3 inch)
- Adjustable wrench
- Sponge and towel
- Food coloring (for the leak test)
Step by step
- Step 1
Lift the tank lid. If the chain is tangled or too tight, adjust it so it has about half an inch of slack when the flapper is closed.
- Step 2
Check the water level. If water spills into the overflow tube, lower the float by turning the adjustment screw or sliding the clip down.
- Step 3
Do a dye test: add a few drops of food coloring to the tank and wait 15 minutes without flushing. Color in the bowl means the flapper leaks.
- Step 4
Turn off the supply valve behind the toilet and flush to drain the tank.
- Step 5
Unhook the old flapper from the overflow tube ears and the chain. Clip on the new flapper and attach the chain.
- Step 6
Turn the water back on, let the tank fill and flush a few times to confirm it seals and stops.
When to stop and call ProFix
If you see any of these, stop and call us:
- The shutoff valve won't turn or leaks when you touch it
- Water leaks at the base of the toilet or on the floor
- The tank itself is cracked
- It still runs after a new flapper and float adjustment (fill valve likely needs replacing)
Not in the mood to DIY? A ProFix pro can handle it for you in Chicago Metro and Dallas–Fort Worth, with a written price before work starts.
Related guides
These guides are general information for simple repairs. You're responsible for your own safety and for following local codes and your lease or HOA rules. When in doubt, stop and call a licensed professional. All DIY guides