Turn Off the Water

The first step is to turn off your toilet’s water supply. Locate the water supply valve, which is typically located on the wall behind the toilet, and turn it clockwise until it stops. Next, lift the lid off the toilet tank and set it aside.

Examine the Overflow Tube Height

The overflow tube is a vertical tube that is located in the center of the toilet tank and prevents the tank from overflowing. If the overflow tube is too short, it can cause the toilet to constantly run as the water level in the tank will rise above the top of the tube, triggering the fill valve to continue filling the tank with water. If the problem is caused by a faulty overflow tube, replace the flush assembly with a compatible flush valve.

Lower the Water Level

The water level in the toilet tank should be about one inch below the top of the overflow tube. If the water level is higher than one inch below the top of the overflow tube, adjust it by lowering the float ball or adjusting the float arm. If adjusting the float does not lower the water level, the fill valve may be damaged.

Check the Flush Valve Chain

The flush valve chain connects the flapper to the flushing handle. If the chain is too long or too short, it can cause the flapper to not close properly, leading to a constantly running toilet. You should inspect the chain to ensure it’s not too long or too short. If the chain is too long, adjust its length by removing links. If it’s too short, adjust it by adding links.

Check the Flapper

The flapper is a rubber valve that controls the flow of water from the toilet tank into the bowl when you flush. A faulty flapper can cause your toilet to run continuously. Inspect the flapper and look for any signs of damage or warping, and replace it if it’s damaged.

Check the Fill Valve

The fill valve controls the flow of water into the toilet tank, and when it's not working properly, it can cause the toilet to constantly run. The fill valve is located on the left or right side of the toilet tank. Examine the condition of the fill valve by looking for signs of damage, wear and tear, or corrosion. Also, ensure the fill valve is properly connected to the water supply line. If the fill valve is damaged, you’ll need to replace it.

Know When to Call a Plumber

If the steps outlined above do not fix the problem or you’re nervous about attempting DIY toilet repair, it’s advisable to call a nearby plumber to help you fix the issue. A professional plumber will come in with specialized tools and fix the problem effectively. If you’re in need of reliable toilet repair or toilet replacement, reach out to the skilled plumbers at Mr. Rooter Plumbing.