Running Toilet Repair Guide

Turn off the water supply by rotating the shut-off valve located on the wall behind or beside the toilet clockwise until it stops.

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.

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.

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.

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.

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.

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.

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.