One of the most common property maintenance issues that we run into is a toilet that won't stop running.
Most of the calls we receive on this issue occur because of the annoyance of listening to the toilet constantly run. Did you know that a running toilet can waste 30 gallons of water in a day. You can find more information on water waste from a running toilet here https://www.thewaterscrooge.com/blog/how-much-water-does-a-running-toilet-use .
Before you can make repairs to a toilet it is important to understand how your toilet works. Basically when you press the flush handle, the chain will lift a flap that lets the water in your toilet tank flow into the toilet bowl. The water drains down and and the flapper will drop and close the opening. When the water flows into the toilet bowl, the float will lower. The float connects to a float valve. This valve will open when the float is lowered and closes when the tank is full and the float is up. The overflow tube drains excess water into the bowl if the water level in the tank gets too high.
Once you understand how your toilet works you can try and find the source of the leak and find out why the toilet keeps running. Issues that cause toilets to continually run include low or high water levels, floats that are no longer functioning as intended, usually from mineral buildup on the float mechanism. Faulty flappers and broken fill valves can also cause the toilet to continually run.
One maintenance call that we received for a leaky toilet was especially difficult to diagnose because typically once you find the source of the leak you can replace the flush valve and float, fill valve or flapper and stop the toilet from constantly running water. This particular call we replaced all of the parts in the tank and it appeared to be repaired but as we waited to verify that the repair was completed we noticed the water in the tank was still dropping very slowly and eventually the toilet would run without being flushed because the float would lower enough and cause the fill valve to start filling the tank again. This continued even after the fill valve, flush valve, float and flapper were replaced. What we found was that the overflow tube was so long that it was siphoning water out of the tank and causing the water to lower. This is not common but we always check the overflow tube as a possible defect.
Toilet repair is one of the least glamorous repairs of the handyman but it is an important repair to make. A running toilet can lead to expensive repairs. This particular service call that we received was on a vacant rental that had flooded. The source of the flood appeared to be coming from the toilet. Because the home was vacant no one was around to shut the toilet water valve off to prevent the overflow and consequently there was significant water damage. The flooding was still somewhat a mystery because the home was vacant and therefore no one had used the toilet to cause it to overflow. When the tenants moved out the toilet was not overflowing. The toilet just overflowed out of the bowl. We finally had to pull the toilet and we found, in the bottom of the toilet, a child's bath toy.
The toy had allowed water to pass through but as the toilet continued to run the toy would move around in the bottom of the toilet until it eventually became wedged and blocked the water flow completely. Once that happened, the continually running toilet water had nowhere to go but over the bowl and out of the toilet. The damage was found after flooding out of the toilet for days and the water damage to the carpets and walls was significant. So even if your toilet water running is not annoying or the water usage is not a concern, taking care of a small maintenance problem could possibly prevent further damage and expensive repairs.