Why is My Toilet Constantly Running?

There is nothing quite like the sound of a toilet constantly running at two in the morning to remind you that your money is literally flowing down the drain. While a running toilet might seem like a minor annoyance, it can actually waste hundreds of gallons of water every day. This leads to a massive spike in your monthly water bill and unnecessary wear on your plumbing system.

Most common reasons for a running toilet are simple mechanical malfunctions that you can fix with a quick trip to the hardware store. This guide will walk you through the common causes and the step-by-step remedies to restore your peace and quiet.

To fix the problem, you first need to see what is happening under the tank lid. If your toilet is working properly, this is what the process will look like: When you push the handle, a chain lifts the toilet flapper, allowing water to rush into the toilet bowl. As the toilet tank empties, the flapper drops back into place to form a rubber seal. Meanwhile, the toilet fill valve opens to replenish the water until the float arm reaches the correct water level, shutting off the water flow.

The most common cause of a running toilet is a worn-out toilet flapper. Over time, the rubber becomes brittle or develops mineral buildup, preventing it from forming a tight rubber seal at the bottom of the tank.

• The Symptom: You hear the water turn on and off intermittently (often called a phantom flush).
• The DIY Fix: Turn off the water supply at the wall and flush the tank to empty it. Remove the old, warped flapper and bring it to the hardware store to ensure you get a new flapper that fits your specific flush valve. Snap the new flapper into place, reconnect the chain, and turn the water back on.

In Las Vegas, our hard water shortens the lifespan of flappers. You may need to replace your flapper every 1 to 3 years, rather than the 4 to 5 years typical in softer water areas.

If the water level in your toilet tank is set too high, it will continuously spill over the overflow tube. This creates a constant stream of water running into the toilet bowl.

• The Symptom: You see water constantly trickling into the overflow tube.
• The DIY Fix: Check the float arm or the adjustment screw on your toilet fill valve. Lower the float so that the water shuts off about an inch below the top of the overflow tube. Modern toilets often use a float cup fill valve rather than a ball float. If you are working with a modern toilet, look for an adjustment clip or screw on the valve body itself rather than a float arm. If the fill valve refuses to shut off regardless of the adjustment, the entire valve likely needs toilet repair.

There is a small, flexible tube connecting the fill valve to the overflow tube. If this tube is pushed too far down into the overflow tube, it can create a siphon effect that pulls water out of the tank.

• The Symptom: The tank never seems to reach the full water level, keeping the fill valve open.
• The DIY Fix: Simply pull the tube out of the overflow tube and clip it so it sits just above the opening. This ensures the water flow goes into the tube without creating a vacuum.

If you have adjusted the float and replaced the flapper, but the toilet still runs, the fill valve itself may be worn or clogged with mineral deposits. In areas like Las Vegas with extremely hard water, this is especially common.

• The Symptom: The toilet will continue to run after adjusting the float and replacing the flapper.
• The DIY Fix: Head to the hardware store and pick up a valve replacement kit. Follow the instructions on the kit, but if you run into issues during the fix, contact a licensed plumber.

Most homeowners can handle a new flapper or a basic fill valve replacement using repair kits. However, some toilet repair tasks are better left to a licensed plumber:

If your toilet keeps running despite your best efforts and you need professional repairs, or if you are ready to upgrade to a new toilet, we are here to help. We handle everything from a leaky faucet to complete plumbing overhauls across the Las Vegas Valley.

Tired of your money going down the drain? Call Dr. Cool at (702) 608-6939 or schedule your professional toilet repair online today.