clock menu more-arrow no yes mobile

How to Repair Toilet Tank Components

Ask This Old House plumbing and HVAC expert Richard Trethewey explains the failure points in toilet tanks and how to repair them

Every toilet tank has only a few components that can fail and cause the toilet to stop operating properly: the flush valve, and the fill valve. If there’s a failure with the flush valve, it’s possible that the attached rubber flapper has worn off or isn’t sitting properly in the opening.

Steps for Replacing a Flapper Valve

  1. Check the slack on the chain connecting the flapper to the lever. If it’s too loose or too tight, adjust it so the flapper lifts high enough to flush the toilet and then seals tightly again.
  2. Then, check the condition of the rubber flapper. If it’s worn out, it needs to be replaced.
  3. To replace it, start by shutting off the water to the toilet tank.
  4. Pull the old flapper off the flush valve. There are usually two little ears on the side where the flapper loops on.
  5. Put the new flapper on using the same process in reverse.
  6. Hook the chain onto the tank lever and make sure it’s adjusted properly.
  7. Turn the water back on.
  8. If there’s a failure with the fill valve, it’s possible that the float hasn’t been adjusted properly and excess water is falling into the overflow. Fix this by adjusting the float on the fill valve, which will vary depending on the type of fill valve.


All of the repair parts for this project can be found at home centers.