How to Stop a Running Toilet (and Save Water!)

Author: Your Local Plumber
November 06, 2025

A running toilet isn’t just annoying — it’s expensive. That constant trickle of water can waste hundreds of gallons a day, adding up to higher water bills and unnecessary strain on your plumbing system. The good news? Most of the time, you can fix it yourself in just a few minutes with simple tools.

Here’s how to stop a running toilet and start saving water today.

What You’ll Need

Rubber gloves.
A flathead screwdriver (optional).
A replacement flapper (if needed).
A towel (for any drips or splashes).

Step 1: Remove the Tank Lid

Carefully lift the lid off your toilet tank and set it aside on a towel or soft surface — they’re fragile and easy to chip. Inside, you’ll see three main parts: the flapper (the rubber seal at the bottom of the tank), the fill valve (controls how the tank refills after a flush), and the float (a small plastic piece that rises and falls with the water level).

Step 2: Check the Flapper

The flapper is the most common cause of a running toilet. Over time, it can warp, crack, or fail to seal properly. Push it down gently with your finger. If the water stops running, you’ve found the problem.

Fix: Replace the flapper — they’re inexpensive and available at any hardware store. Make sure to choose one that matches your toilet’s brand and model.

Step 3: Adjust the Float

If the water level is too high, it can continuously flow into the overflow tube, keeping your toilet running. Look for the float (either a ball float or cup-style float) and adjust it so the water level sits about one inch below the top of the overflow tube.

Fix: For a ball float, gently bend the arm downward. For a cup float, use the adjustment screw on the fill valve.

Step 4: Inspect the Fill Valve

If adjusting the float doesn’t help, the fill valve may be the issue. Turn off the water supply (the valve is usually behind the toilet), flush to empty the tank, and check for debris or mineral buildup around the valve.

Fix: Clean the valve, or if it’s damaged, replace it. New fill valves are affordable and easy to install with simple tools.

Step 5: Turn Water Back On and Test

Turn the water supply back on and let the tank refill. Listen for running water after the fill cycle finishes. If it’s silent, you just fixed your toilet and started saving water.

Bonus Tip: Don’t Ignore the Drip

A constantly running toilet can waste up to 6,000 gallons per month — enough to fill a small swimming pool. Even a slow trickle adds up quickly, so it’s worth taking 10 minutes to fix it now.

When to Call a Plumber

If you’ve tried these steps and your toilet still won’t stop running, there may be a more complex issue such as a faulty flush valve or internal leak. That’s when it’s time to call in a professional plumber.

At American Plumbing, we specialize in fast, affordable toilet repairs — and we’ll make sure your plumbing is running efficiently again in no time. Contact us today to schedule your service and stop wasting water.

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