Why Won't My Toilet Stop Running?

A running toilet is more than just a noise nuisance. If your toilet runs long after you flush, it will drive up your water bill and waste gallons of water that you will have to pay for. Sometimes, this problem can be addressed with a little DIY work, but first, you have to find a cause. Below are three common reasons a toilet will run and ways to fix the problem.

1. Leaking Flapper

The hole at the bottom of the tank that fills the toilet bowl is covered by a flapper. If that flapper does not seal properly, the toilet will run. A loose, leaky flapper usually occurs when there is a problem with the chain that connects it to the handle arm or when the flapper itself becomes old and worn.

To fix this, take the lid off of the tank and push the flapper down, without moving the handle. If this stops the toilet from running, you have a worn flapper to replace. If not, then test the chain and the hinges. If the chain is not attached properly, re-attach it or replace it, or adjust the chain if it is too tight. To replace the flapper, you need to:

• Shut off the water
• Remove the old flapper by disconnecting it from the system
• Attach the flapper to the hinge
• Connect the chain and flush handle
• Turn the water back on and see if the problem stopped

The challenge to this particular task is the fact that flappers must fit the overflow tube they were designed for. Even “universal” flappers may not fit. If your toilet assembly is old, you may not be able to find one that seals. In this case, you will need to replace the entire overflow tube and flapper system, which is a time-consuming, difficult task.

2. Problems With the Fill Valve

An adjustable float or fill valve controls the water level in a toilet tank. If the float is set too high, water can spill into the overflow tube. This causes the toilet to run because the fill valve fails to shut off.

Phoenix plumbing maintenance plans help avoid toilet, sink, and other plumbing issues. To check for fill valve problems yourself, open the tank and locate the fill level mark, which should be somewhere on the inside back of the tank. If you do not see a mark, make one about one inch down on the overflow tube. Then, adjust the float up or down as needed. Flush the toilet and see if the water stops flowing when the tank reaches that optimal level, continue slight adjustments and flush until the proper fill level is reached.

3. Faulty Fill Valve

If the float seems to be in the right place and the flapper is shutting properly, the next likely problem is with the fill valve itself. If you have already checked the other two problems, consider replacing the valve.

Pick up a fill valve at the hardware store and try to find something that matches the existing one. Unlike flappers, these are usually a one-size-fits-all product. To replace, you will need to:

• Turn off the water to the toilet
• Hold the flush lever down to allow most of the water to drain from the toilet
• Use a shop vac to remove the remaining water from the tank
• Disconnect the water supply valve from the fill valve
• Loosen the nut holding the fill valve into the tank, removing the old valve
• Reverse these steps to attach the new fill valve
• Adjust the float according to the directions on the valve
• Turn on the water and test for leaks

Most of these tasks can be completed in less than an hour, and stopping that running water noise brings a tremendous sense of accomplishment. However, if the problem persists or these steps do not fix your running toilet, call in an expert plumber for help.