How to Replace a Water Shut Off Valve on a Toilet

Turn off the water supply valve under the toilet by turning it clockwise. Flush the toilet to drain the water from the tank. Using towels, absorb any remaining water from the tank. Locate the main water shut off valve to the home and turn off. This is usually located in the basement or crawl space.

Open a water source in the lower level of the home, below the level of the toilet you are working on. This will empty the water lines in the home, saving you hassle under the toilet. Return to the toilet shut off valve. Unscrew the water supply hose from the bottom of the toilet tank. This can be done by hand, or for more stubborn connections, using a pipe wrench.

While holding the shut off valve with your hand or a pair of slip-joint pliers, unscrew the compression nut with a pipe-wrench. This will remove the shut off valve assembly from the water line. Discard the damaged valve and attached supply hose.

Attach the new shut off valve by slipping the new assembly into the water line and tightening the compression nut. Again, hold the shut off valve with one hand while tightening the nut with the other. This prevents the water line from twisting and breaking.

Tighten the packing nut, located directly behind the handle of the shut off valve, gently. Attach the new toilet supply hose to the shut off valve and to the base of the toilet tank. Wrap Teflon tape around the threads to ensure a tight seal.

Open the main water supply valve to the house. Slowly open the toilet shut off valve by turning counterclockwise. Check for leaks around the base of the tank and around the water shut off valve. If there is a leak at the base of the tank, tighten the supply hose gently. For leaks at the valve, gently tighten the packing nut. Your new shut off valve will last for years to come, saving you some green along the way.