Toilet Running Constantly? Here Is How to Fix It
A running toilet wastes up to 200 gallons per day. The fix takes 10 minutes and costs under $10.
Why Your Toilet Keeps Running
A running toilet means water is continuously flowing from the tank into the bowl. This happens when the flapper valve does not seal properly, the float is set too high, the fill valve is faulty, or the overflow tube is too short. The most common cause by far is a worn flapper — a $3 rubber piece that sits at the bottom of the tank.
Fix 1: Replace the Flapper
Lift the tank lid and look at the rubber flapper at the bottom. If it is warped, cracked, or coated in mineral buildup, it is not sealing. Turn off the water supply, flush to empty the tank, unhook the old flapper, and snap the new one in place.
Fix 2: Adjust the Float
If the water level in the tank is above the overflow tube, the float is set too high. For a ball float, bend the arm downward slightly. For a cup float, squeeze the clip and slide it down the rod. The water level should be about half an inch below the top of the overflow tube.
Fix 3: Replace the Fill Valve
If adjusting the float does not help, the fill valve itself may be worn out. Universal fill valves cost $8–12 and are designed for easy DIY installation. Turn off the water, flush, disconnect the supply line, unscrew the old valve, and install the new one following the package instructions.
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