How to Fix a Troublesome Toilet Flapper

If your toilet runs constantly, or you notice occasional “phantom flushes” when no one is even near the toilet, the flapper is most likely to blame. This is the small rubber device at the bottom of the tank that opens when you flush the toilet and closes again to allow the tank to refill. Fortunately, you can fix or replace a finicky flapper without difficulty. 

Before you get started, turn the valve behind the toilet to stem the flow of water as you work. Then, follow these tips to fix a troublesome toilet flapper. 

Adjust the Chain 

Lift the lid off the tank, and take a look inside. You’ll see a thin metal or plastic chain connecting the rubber flapper to the handle arm. This is what lifts the flapper when you flush the toilet. Assess the length of the chain. It should be long enough that the flapper sits properly over the opening but short enough that it doesn’t get caught under the flapper as it closes. Shorten or lengthen the chain by a link or two, and see if that fixes the problem. 

Clean the Flapper 

Old flappers can collect gunk around the rim, preventing them from closing tightly. A slow leak can lead to phantom flushes and water waste. With the valve behind the toilet turned off, press the handle to empty the tank. Then, gently lift the flapper off its seat and wipe it clean. For stubborn mineral buildup, try a scouring pad or old toothbrush. Finally, close the flapper, turn the water back on, and see if the flapper sits tightly now. 

Replace the Toilet Flapper 

If adjusting the chain and cleaning the flapper doesn’t work, try replacing it. Toilet flappers are inexpensive and available at your local hardware store. It’s wise to bring the old flapper with you to make sure you purchase a compatible replacement.  

Simply unsnap the two arms from the posts holding the flapper in place. Then, unhook the chain from the top of it. Attach the new flapper to the same link on the chain and insert the arms onto the posts. While you’re at it, wipe down the interior of the toilet tank with a rag to remove mold and mineral buildup. 

With the new flapper firmly in place, turn the water back on. The tank should fill to the proper level automatically. Once it stops, test your installation by flushing the toiletHopefully, your days of dealing with a troublesome flapper are now behind you! 

While it’s easy enough to troubleshoot and replace a toilet flapper, this is far from the only thing that can go wrong with your commode. Count on Albert Nahman Plumbing & Heating the next time you need toilet repair or replacement in Berkeley. We offer fair prices and guarantee our work with nearly four decades of experience to back us up. Contact us at 510-843-6904 today to schedule the plumbing services you need! 


Albert Nahman Plumbing & Heating – | 

Berkeley, CA