⚡ SheetCraft is experimental — send feedback or vote on guides to help us improve.
← Back to Home

Running Toilet Repair Guide

mediumHome Repair1 hr

Stop wasting water and silence your bathroom with this straightforward running toilet repair guide. Designed for homeowners and beginners, this tutorial teaches you how to diagnose common leaks and replace faulty components using basic household tools.

Safety Warnings

  • Avoid overtightening fittings as this can crack the porcelain tank or other components.
  • Handle the porcelain tank lid with care; it can crack and break easily if dropped.

Tools Needed

Adjustable wrench — 8-inch
Buy →
Pliers — channel locks
Buy →
Screwdriver — Phillips #2
Buy →
Sponge or rag — absorbent
Buy →

Materials

Toilet flapper — universal or model-specific(1)
Buy →
Fill valve assembly — universal or model-specific(1)
Buy →
Towel — old/absorbent(2)
Buy →
Bucket — 5-gallon(1)
Buy →

As an Amazon Associate we earn from qualifying purchases.

Steps

1
Turn off the water supply by rotating the shut-off valve located on the wall behind or beside the toilet clockwise until it stops.
2
Remove the toilet tank lid carefully and place it on a towel to prevent cracking. Flush the toilet and hold the handle down to drain as much water as possible from the tank, then use a sponge to remove any remaining water.
Tip: Take a picture of the current setup before removing parts for reference during reassembly.
3
Diagnose the cause of the running water. If water is spilling into the overflow tube, the fill valve or float needs adjustment. If water is leaking into the bowl without overflowing the tube, inspect the flapper and chain.
Overflow Tube Float Flapper Check Water Level here Check if water spills into the tube (valve issue) or leaks below (flapper issue).
4
To fix flapper issues, disconnect the chain from the handle lever and pull the rubber tabs off the overflow tube pegs. Clean the flush valve seat with a sponge or vinegar to remove mineral deposits. Install a new flapper and adjust the chain to have about 1/2 inch of slack.
Handle lever Overflow tube Flapper Pull upward Remove the flapper by pulling its tabs off the overflow tube pegs.
5
To fix fill valve issues, place a bucket under the tank, disconnect the water supply line using pliers, and unscrew the locking nut from the bottom of the tank. Remove the old assembly and install a new fill valve, ensuring the float is set so the water level sits approximately 1 inch below the top of the overflow tube.
Locking nut Float Bucket unscrew nut Remove locking nut to extract the fill valve assembly.
6
Reattach the water supply line to the base of the tank, tightening the nut by hand and then snugging it with pliers. Slowly turn the water supply valve back on and allow the tank to refill.
7
Test the repair by flushing the toilet. Observe that the water stops flowing once it reaches the set point and check the base of the tank and supply line for any leaks before replacing the lid.
8
If the toilet continues to run after these steps, or if you are uncomfortable working with plumbing systems, call a professional plumber to diagnose potential cracks in the tank or damaged seals.

Pro Tips

  • Invest in quality replacement parts from brands like Fluidmaster or Korky for long-lasting results.
  • Bring the old flapper or fill valve to the hardware store to ensure an exact match in size and style.

When to Call a Professional

If the toilet continues to run after replacing internal components or you find a cracked toilet bowl, call a licensed plumber.

Share this guide