There was evidently a very slow water leak so that when the tank level dropped to a certain level, the fill valve turned on to top off the tank. It was an annoying but minor problem that was stopped by jiggling the flush handle after each flush.
I finally stopped procrastinating and fixed the problem. In this case, the chain from the flush handle lever to the flapper was getting kinked. This caused the chain to be too tight and didn’t allow for proper seal, thus the intermittant tiny leak. All I had to do was loosen the chain by one link.
Running toilets are a bigger problem than we imagine. A plumbing association study in 2012 determined that 25% of the toilets in the United States leak. Running toilets waste at least 70,000 gallons of water each year. Most of the running toilets can be easily and cheaply fixed by anybody. No special training nor tools are required, either.
About ten years ago, I taught myself how to repair my toilet tank after it became seriously leaky. I had made the mistake of hanging “self-cleaning” products onto the side of the tank. Each flush released a metered amount of chlorine based detergent into the water. Not only did the product fail to clean the toilet bowl and tank, it destroyed the workings of the flush mechanisms. The flush valve became corroded, the flapper disintegrated, and the end of the flush lever was ready to break off.
The first thing to do was to discard the automatic cleaner. The next step was to take a shopping trip to the local hardware store to buy replacement toilet tank parts. They included a brand new flush handle lever and a flapper. I decided to replace the old fashioned globe shaped float and ballcock mechanism with a more modern floating cup fill valve.
Most brands of toilet tank repair parts include installation and adjustment instructions on the packages. There are minor variations with each type, so I recommend following the directions to the letter.
To begin the valve replacement, locate and shut off the supply valve that leads to the bottom of the tank. It’s usually a small nickle or chrome plated faucet knob attached to a flexible pipe. Flush the toilet and make sure all the water drains from the tank. Any small remaining amount should be soaked up with a sponge to avoid water dripping onto the floor during the valve installation process.
Use a large crescent wrench or pipe wrench to loosen and remove the nut at the end of the supply pipe that attaches to the old fill valve. The unit should lift out easily. Make sure the valve area at the bottom of the tank is smooth and free of any residue or debris, then follow the installation instructions for the new valve assembly.
Because I needed to replace the flush handle lever, I used a crescent wrench to remove the nut that held it in place. I installed the new one by reversing the procedure, taking care to align the part with the notch in the tank.
The flapper is the least costly part of the tank repair and is the easiest one to install. Make sure to get a flapper made of the proper material. Some of them are made with a stiffer plastic and some are made from a more flexible, rubbery substance. I got an exact replacement flapper just to be on the safe side.
Install and align the flapper with the drain hole of the tank according to package directions. Then attach the chain from the flapper to the flush handle lever. Leave some chain slack, not too much nor too little.
Turn on the supply valve to fill the tank. Check carefully for leaks. You’re finished. Over the next day or so, double-check and monitor for any slight leaks. If there are none, you can enjoy a trouble free toilet.
At least once each year, inspect your toilet tank for sticking valves or a troublesome flapper. This is also a good time to check your sink, tub, and shower faucets for leaks, too. We want to be sure to preserve our precious water resources and keep our water bills low.