How to Fix a Running Toilet

Concept of modern decoration design of bathroom with toilet and shower decorating with black and white ceramic for luxury hotel, condominium, residential

Have you noticed your toilet just won’t stop running lately? It may not seem like a big deal, but a toilet that is constantly running can waste a lot of water, giving you an unnecessarily high water bill. It can also increase the chances of rust stains on your porcelain throne. Luckily, repairing your toilet may be easier than you think. Follow these steps for a simple DIY fix you can have done in no time!

Replace the Flapper

Inside flapper of a toilet bowl

One of the most common reasons for a running toilet is a bad flapper. Toilet flappers provide a seal between the tank and the bowl. Over time they can wear out and cause water to run into the bowl.

To test your flapper, use your hand, a stick, or a similar tool to press down on it. If you see or hear the water has stopped running as you are pressing down, it’s time to get a replacement. If the water continues to run, there may be another issue.

Replacing the flapper is easy. Start by turning off the water supply located under the toilet. There will be a small knob attached to the supply line. Turn it clockwise to shut off the water. Then flush the toilet to drain most of the water from the tank. Now you can unhook the flapper and replace it with a new one of the same size and type. Follow the instructions that came with your replacement part, making sure to leave a little slack on the chain when the flapper is closed - about ¼” - ½”.

Check the Fill Valve

Internal plumbing of the inside of a tank of a modern toilet

If the water did not stop running when you checked the flapper, you may have a bad fill valve. To replace it, start by turning off the water supply, flushing the toilet, and cleaning any remaining water from the tank. If there is water remaining in the tank, you can remove it by using a sponge or a vacuum capable of handling wet material, such as a Channellock Wet/Dry Vacuum.

Next, disconnect the water supply by unscrewing the supply line from the outside of the tank. Now you can install a replacement fill valve, following the directions provided with the new piece.

Adjust the Overflow Pipe Height

Latin American plumber fixing a toilet in the bathroom

If you have installed a new fill valve, check to make sure the overflow pipe is at or below the critical level mark located on your new valve. If it is above that mark, you’ll need to shorten it. You can lower the height by using a hacksaw to cut the pipe about one inch lower than the critical level mark.

If your toilet won’t stop running, don’t put off repairing it. These fixes are easier than you think and can be done by anyone with little to no plumbing experience. Your water bill doesn’t have to suffer. Follow these steps to bring peace of mind with a porcelain throne in tip-top shape.

While do-it-yourself projects can be fun and fulfilling, there is always a potential for personal injury or property damage. We strongly suggest that any project beyond your abilities be left to licensed professionals such as electricians, plumbers, and carpenters. Any action you take upon the information on this website is strictly at your own risk, and we assume no responsibility or liability for the contents of this article.


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