How to Fix a Running Toilet

A running toilet isn’t just annoying—it can waste hundreds of gallons of water and increase your utility bill. Fortunately, fixing a running toilet is often a quick and straightforward DIY task. Here’s how to stop your toilet from constantly running.

ARTICLES

2/26/20252 min read

a picture of a person's hand washing their hands
a picture of a person's hand washing their hands

1. Why is Your Toilet Running?

A toilet typically runs due to one of the following reasons:

  • Faulty Flapper: The flapper might not be sealing properly, allowing water to flow continuously from the tank to the bowl.

  • Chain Issues: The chain connecting the flapper to the flush handle may be too short or tangled, preventing the flapper from sealing.

  • Float Problems: The float may be set too high, causing the water level to rise above the overflow pipe.

  • Worn Out Fill Valve: A worn or damaged fill valve can cause water to leak or overflow.

2. Tools and Materials Needed

  • Tools:

    • Pliers or adjustable wrench

    • Screwdriver

    • Utility knife

    • Towel or sponge (to soak up water)

  • Materials:

    • Replacement flapper (if needed)

    • Replacement fill valve (if needed)

3. Check and Adjust the Flapper

  • Turn Off the Water: Locate the shut-off valve behind the toilet and turn it clockwise to stop the water supply. Flush the toilet to drain the tank.

  • Inspect the Flapper: Open the tank lid and check if the flapper is sealing correctly. If it’s worn, warped, or cracked, it needs to be replaced.

  • Adjust the Chain: Ensure the chain has just enough slack to allow the flapper to seal completely. If it’s too short or tangled, adjust the length.

  • Replace the Flapper: If necessary, detach the old flapper and install a new one compatible with your toilet model.

4. Check the Overflow Pipe

  • Inspect the Water Level: The water level should be about 1 inch below the top of the overflow pipe. If it’s too high, water will continuously flow into the bowl.

  • Adjust the Float:

    • For a float cup: Squeeze the clip on the side of the float and slide it down to lower the water level.

    • For a ball float: Turn the adjustment screw on the fill valve or bend the float arm downward to lower the water level.

5. Replace the Fill Valve (If Necessary)

If the fill valve is faulty or leaking:

  • Remove the Old Fill Valve: Turn off the water supply and disconnect the water line. Unscrew the locknut beneath the tank and remove the old fill valve.

  • Install the New Fill Valve: Insert the new fill valve into the tank and secure it with the locknut. Attach the refill tube to the overflow pipe.

  • Reconnect the Water Supply: Reconnect the water line, turn on the water, and check for leaks.

6. Test the Toilet

  • Flush and Observe: Flush the toilet and check for any leaks or running water sounds.

  • Adjust as Needed: Make minor adjustments to the chain length, float level, or flapper positioning for optimal performance.

Need Professional Help?

Fixing a running toilet can save you money on water bills and prevent water damage. If you need assistance or prefer to have a professional take care of it, contact ProHands Handyman. We provide reliable plumbing repair services to keep your bathroom functioning smoothly.

📞 Call or text: 818-401-7766
📍 Serving Glendale, Burbank, Pasadena, and surrounding areas.

Contact us today for a free estimate and professional repair!