How to replace a flapper

How To Replace A Toilet Flapper

The simplest plumbing lesson I could give is how to replace a toilet flapper. That’s not to say that you should know how to do this.

Not everyone does. Believe me, there are plenty of things that I don’t know.

But if nobody has taught you yet or it just has never come up, then this blog post will come in handy. And I’m glad to explain it.

Flush Valve Seals

Flush valve seals are a term that plumbers use when they have to charge you more than they’re comfortable charging.

Usually, that is the case when it’s the only thing you needed done. They have to charge the travel expense for getting to your home.

And that puts everybody in an uncomfortable situation. But it’s not a made up to replace a flush valve, Lee's summit plumber

The flush valve seal is actually what a flapper is. It’s just one of many types of flush valve seals.

I only mention this because there are both new and old toilets that don’t use flappers. I’m writing this post for most people.

And the flapper style flush valve seal is the most common. I may get to some of the other types in a later post but I want to help as many people as possible first.

It’s called a flush valve seal because it’s attached to the flush valve and makes a seal at the opening to allow water to fill up the tank.

The flapper is what you’re pulling up on when you flush the toilet thereby breaking the seal. It allows the tank water to flow into the bowl.

But if you want to know more about that read How toilets work.

How To Replace A Flapper

For now we’ll get to how to replace a flapper.


  1. Shut off the water to the toilet at the water shut offs. If yours doesn’t work properly then shut the water off to house. 
  2. Flush the toilet.
  3. Remove the flapper chain from the end of the handle.How to replace a flapper
  4. Remove the flapper from the flush valve by pulling the little rubber flapper eyelits off the plastic flush valve ears.
  5. Gently run your finger over the surface of the flush valve seal where the flapper sits. You’re feeling for any imperfections or debris on that surface. If there’s debris, remove it. If there’s a small groove or dent then lightly sand it away with a fine grit sandpaper or plumbers sandcloth.
  6. Get your new flapper. If there is a circular portion of rubber between the two eyelits on the flapper remove it with a knife. Discard it. It’s only there if you have a damaged flush valve. But it isn’t usually there. They’ve kind of done away with that model. There are some that have a plastic circular portion that’s easily removed.
  7. Set the flapper on the flush valve seal where it will sit after installation.
  8. Attach the rubber eyelits to the corresponding flush valve ear. If your flapper is partially plastic it may need to be pressed onto the ears of the flush valve. Be careful not to damage the flush valve ears.
  9. Hold the chain up to the handle directly above it at the corresponding handle hole to measure the correct length to adjust the chain. Always leave just a little slack in the chain.
  10. Move the clip from the end of the flapper chain to the correct spot on the chain for optimal tension and slack.
  11. Remove any excess chain and discard. You can usually just twist off one of the links by hand.How to replace a toilet flapper, Lee's Summit plumber
  12. Test the flapper for correct length by pressing the handle and watching it.
  13. Turn the water back on.
  14. Flush the toilet. If it doesn’t flush, shorten the chain. You should never have to hold a toilet handle down to make it flush. If it’s not sealing you may have the chain too short.
  15. Check for leaks by either watching for running water at the waters edge inside the bowl or putting about eight drops of blue food dye in the tank and coming back thirty minutes later to check for food dye in the bowl.

In Conclusion

Don’t let this intimidate you. It’s a really simple chore and you’ll giggle when you’re done.

But also don’t be too embarrased to ask for help. If this is not something you feel comfortable doing or you’d prefer to have someone else do it then call us.

At Advocate Master Plumbing we’re only too happy to help.

Don’t forget that we’re the locally owned and operated family plumbing service company that guarantees you’ll always get a master plumber.

We also install and repair water heaters, sump pumps, frozen pipes, garbage disposals, faucets, gas pipe, water pipe, drain pipe and all manner of residential plumbing.

And check out our 5 STAR reviews on Google, YELP & Facebook at the bottom of the website.


Here’s a video I like that may help with those of us that are visual learners.

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