top of page
  • Writer's pictureKevin Peterson

Home Improvement Tip: How to fix a running toilet?

As a realtor, I love helping people, especially friends and family in our community. Here's a quick story of my heroic, yet comedic, plumbing adventure in the townhouses of Fiesta Gardens along with instructions below on how to fix a running toilet.

A dear friend from my children's school was in need of a toilet valve savior for 4 toilets that were constantly running. After a couple decades of being a landlord and too many high priced contractor bills, I knew I had the experience so volunteered to help replace the toilet parts that were causing the leak. Armed with a wrench, new Fill Valves from Home Depot, and the confidence of a plumbing veteran, I embarked on my quest. On the very first toilet we ran into an obstacle; the angle valve (which shuts off water to the toilet) was made of a plastic part called a LSP Pull Stop Box Valve instead of a typical brass angle valve. No matter how hard we pulled on the LSP, the water would not shut off.

home improvement tips toilet angle valves

Our next option was to shut off the water to the entire house at the main. A three story townhome meant quite a bit of walking so my dear friend helped by shutting off and on the main water valve in the garage as we tested each replaced valve. That worked well for the first two toilets but then on the third and fourth, the toilet supply line hoses burst at the connection. This was my fault as I forgot to remind my friend to turn on the water slowly as the water came back at a high pressure. Luckily, not too much water escaped as we quickly shut off the main water valve then hustled to Home Depot for new toilet supply line hoses. Within a fairly short time, a couple towels, some hand tightening of lines, and it was all done.

In short, my friend saved $100's on hiring a plumber. Their toilets should be good now for another 20 years.

If you have any questions about home improvement or something is not quite right in your house, please feel free to reach out to me anytime. I'd love to help as much as I can.


Home Improvement Tips: How to fix a leaking toilet?

Most common causes of a running toilet are inside the toilet tank and are one or all of these reasons:

Let's evaluate each...

Diagram of parts inside of toilet reservoir tank
Example toilet reservoir tank

Test if a leaky Flapper

What is the flapper?

The Flapper is a rubber or silicon part that seals the water inside the toilet tank. When you flush the toilet, this flapper is pulled up by the handle, and flushes the reservoir of water in the toilet tank down into the toilet bowl. This flapper typically lasts 20 years or less, depending on the hardness of your water.

How to test?

  1. Ensure the Fill Tube is at least 1/2-inch above the water line. If below the water line, proceed to the "Overflow Pipe at the wrong height" section.

  2. Push down on the flapper with a stick when you hear the toilet water running and listen for it to stop.

Expected result?

If the flapper isn’t sealing properly, then pushing on the lid should stop the water from leaking. Replace the toilet flapper immediately. Home Depot sells this part between $6-13.

Still leaking?


Test if the Fill Valve is the leak

What is the Fill Valve?

The Fill Valve allows the water from your home into the toilet and shuts off when the float reaches the desired height of water in the toilet tank.

How to test?

  1. Flush the toilet and look for a visible fill valve leak.

  2. Lift up on the toilet float arm when the tank is filling to see if the water stops.

  3. Bend or adjust the toilet float arm so the tank stops filling when the water level is 1/2- to one-inch below the top of the overflow pipe.

Expected result?

The Fill Valve should shut off when the float arm is all the way up and the flapper has a good seal. If the fill valve still leaks, replace the Fill Valve immediately. Our Home Depot nearest us sells the Fluid Master Fill Valves between $9-21.

Still leaking?


Test if it's the Overflow Pipe

What is an Overflow Pipe?

The Overflow Pipe is designed to prevent water from over flowing out of the toilet tank and all over the bathroom floor.

How to test?

  1. Ensure the Flapper is sealing properly (see above).

  2. Ensure the Fill Valve is not leaking and able to shut off when float is at maximum height.

Expected result?

The Fill Valve float should stop the water 1/2 inches below the Overflow Pipe if the Fill Valve float is properly adjusted. If not, adjust the height of the Fill Valve float.

That should fix your running toilet.


If you still have issues, then check for water leaking outside of the toilet tank and the toilet itself. Text or call me at 650.451.8763 and happy to walk you through additional troubleshooting or other home improvement tips.

8 views0 comments
bottom of page