By reading the following DIY project you consent to the terms in the DIY disclaimer.

How to Fix a Running Toilet

Learning how to fix a running toilet introduces new do-it-yourselfers to the world of plumbing. Fixing or replacing the components within a toilet tank requires no special tools. New parts are often available at most home improvement stores. The improper operation of the fill valve, float arm, overflow pipe, or flapper could cause your toilet to run. You’ll need to do some diagnostics to find the source of the problem.

Tools Necessary How to Fix a Running Toilet

A valve on the supply line to the toilet tank will allow you to shut off the water while you work. Always make sure you know where the main shut off valve to the house is located in case the valve on the supply line does not work.

  • Sponge
  • Pliers
  • Utility knife or scissors
  • Hacksaw
  • Wooden paint stirring stick
  • Gloves
  • Safety glasses

Steps for How to Fix a Running Toilet

  1. Put on your gloves and safety glasses.
  2. Take the lid off of the toilet tank.
  3. Check the flapper that covers the hole that sends the water into the bowl.
  4. You may visibly see that it’s stuck open due to a kink in the chain.
  5. Adjust the chain so that the flapper shuts fully.
  6. If the flapper chain was not the problem, push the flapper firmly against the hole.
    1. If water continues to run into the bowl, the flapper is faulty and you should proceed to Step 10.
    2. Otherwise, continue diagnostics in Step 6.
  7. Evaluate the fill valve by flushing the toilet.
  8. While the tank is filling, lift the float arm that has the float attached.
  9. Lifting the float arm should shut off the water inside the tank.
  10. Let go of the float arm and allow tank to finish filling.
    1. If it fills to the top of the overflow pipe, then that is the source of the running toilet.
    2. Slightly bend the float arm downward so that it shuts off the fill valve when water is still 1/2 inch below overflow pipe.
    3. If lifting the float arm DOES NOT shut off the water completely, then the fill valve has failed.
    4. Go to Step 16 to replace fill valve.
  11. To replace flapper, buy a new one from a hardware store.
  12. Turn off water to toilet tank with the valve on the supply line.
  13. Flush toilet to empty tank.
  14. Remove old flapper.
  15. Fit new flapper into tank hole.
  16. Attach chain to the flush lever arm so that it hangs slightly slack when flapper is shut.
  17. Learning how to fix a running toilet may require replacing the fill valve.
  18. Shut off water supply to toilet tank. How to Fix a Running Toilet Water
  19. Flush the toilet to empty the tank.
  20. Sponge out the water lingering in the bottom of the tank.
  21. Pliers will help you disconnect the water supply line.
  22. Unscrew the locknut under the tank that holds the fill valve.
  23. You can now lift out the old fill valve.
  24. Slide a new fill valve into the tank.
  25. Secure the fill valve from below with the locknut.
    1. Tighten it about half a turn beyond hand tight.
  26. If the new fill valve’s critical level mark is below the top of the overflow pipe, take the hacksaw and reduce the height of the pipe.
    1. The overflow pipe should be about 1 inch lower than the critical level mark.
  27. Slide the new fill tube on to the nipple extending from the fill valve.
  28. Connect the fill tube with the included angle adapter to the overflow pipe.
    1. Cut the tube shorter if it kinks up.
  29. Make sure that the flapper chain is connected to the flush lever.
  30. Reconnect the water supply line and open its valve.
  31. Refill the tank and flush to confirm that everything is working well.

Toilet Repair Services From Oliver

Following the steps for how to fix a running toilet above should solve your problem. When more extensive plumbing repairs land on your to-do list or you are simply having trouble with the above, consider talking to the licensed team at Oliver. Our experts know how to complete all plumbing repairs and have been helping homeowners in Pennsylvania, New Jersey, and Delaware since 1971. Tell us what you need and ask for an estimate today.

Need help with this project?

If you do not have the time, tools, or experience necessary to complete the project, please contact the professionals at Oliver for help.

Contact us today at 1-888-810-2681 Get a Free Estimate
Google Rating
Based on 1968 reviews
Schedule Online

"*" indicates required fields


This field is for validation purposes and should be left unchanged.

During extreme conditions, response times may be delayed. We will do our best to accommodate your request. Your patience is appreciated.

Schedule Online