How to Replace a Toilet Flapper
Quick Answer
Turn off the water supply, drain the cistern, remove the old flapper, attach the new flapper to the overflow tube, and reconnect the chain.
How to troubleshoot How to Replace a Toilet Flapper
A faulty flapper can cause your toilet to run continuously or waste water. This guide shows you how to replace the flapper in a standard toilet cistern.
Step-by-Step Fix
- Turn off the water supply at the valve behind the toilet and flush to empty the cistern.
- Remove the cistern lid and place it safely aside.
- Disconnect the old flapper chain from the flush lever arm.
- Unhook the old flapper from the overflow tube ears.
- Attach the new flapper to the overflow tube in the same way.
- Connect the chain to the flush lever arm, ensuring there is slight slack when the flapper is down.
- Turn the water back on and test the flush.
Common Error Codes
| Code | Meaning | Resolution |
|---|---|---|
| Toilet still runs | Chain too tight or flapper not seating | Adjust the chain length so there is a small amount of slack. |
| Weak flush | Flapper opens too briefly | Adjust the chain to allow the flapper to stay open longer. |
Frequently Asked Questions
How do I know which flapper size to buy?
Check if the overflow tube is 2-inch or 3-inch; measure to be sure.
Do I need to turn off the water?
Yes, to prevent the cistern from refilling while you work.