How to Replace a Toilet Flush Valve

Repairing toilet leaks can save money on your water bill and help conserve water. If you’ve got a water leak from the tank into the bowl, you may be able to fix it by replacing the flush valve inside the tank. To test for a toilet leak, place a few drops of food coloring in the tank and let it sit for about half an hour. Then, check to see if the food coloring is in the toilet bowl water. If it is, you’ve got a leak.

To replace the toilet flush valve, you’ll need an adjustable wrench, plumber’s wrench, channel-locking pliers, a large flat screwdriver, penetrating oil, a new flush valve and flapper, a small bucket and a couple of old towels.

Turn off the water supply to the toilet.

The water shut-off valve should be located underneath the toilet tank. Turn it clockwise to stop the water.

Uncover and drain the toilet tank.

After you take the lid off the toilet tank, set it aside carefully so it doesn’t get broken. Then, hold the flush handle down until most of the water has drained out of the tank. Use towels to mop up any remaining water in the tank

Disconnect the water supply line from the tank.

This could be a tube or a hose, and there is a nut that will have to be loosened by rotating it counterclockwise with the channel-locking pliers.

Remove the toilet tank from the bowl.

Use the flathead screwdriver and adjustable wrench to loosen and remove the nuts and bolts that are holding the tank and bowl together. Carefully lift the tank off the bowl and set it aside.

Remove the flush valve from the toilet tank.

Take the rubber gasket off the bottom of the tank, then use a plumber’s wrench to unscrew the locknut that attaches the flush valve to the tank. Then you can remove the old flush valve.

Install the new flush valve.

Follow the manufacturer’s instructions that are included with the replacement part. Put the rubber gasket back on the bottom of the tank.

Attach the toilet tank back onto the bowl.

Use the adjustable wrench to tighten the tank nuts and bolts that you removed earlier so there won’t be any water leaks.

Reconnect the flush lever arm and fill tube.

Attach the flapper chain to the flush handle and hook the fill tube onto the overflow pipe.

Reconnect the water supply to the toilet tank.

Attach the supply line to the fill valve and use the adjustable wrench to tighten the nut.

Fill the toilet tank with water and check for leaks.

Once the water supply line has been reconnected, turn the water shut-off valve counterclockwise and let the tank fill with water. Then, test your work by flushing the toilet and watching for any water leaks.

If you need help or just don’t want to tackle this project on your own, call the professionals at Bailey Brothers Plumbing at 405-896-9988. We’re Oklahoma City’s experts on pluming repair and service, and we’ll install your new toilet flush valve quickly and correctly.