A running toilet can be a major nuisance, wasting water and driving up your utility bills. The good news is that fixing a running toilet is a relatively simple DIY task that you can tackle without needing a plumber. In this guide, we'll walk you through the steps to diagnose and fix the issue yourself.

1. Turn Off the Water Supply

Before you start working on your toilet, the first thing you need to do is turn off the water supply. Look for the shut‑off valve behind the toilet near the wall. Turn it clockwise to stop the water flow. This will prevent any more water from filling the tank while you're working on it.

2. Remove the Toilet Tank Lid

Next, remove the lid from the toilet tank and set it aside in a safe place. You'll need to access the components inside the tank to identify the cause of the running water.

3. Inspect the Flapper Valve

The most common cause of a running toilet is a worn‑out or faulty flapper valve. This rubber valve sits at the bottom of the tank and seals the hole that releases water into the toilet bowl. When the flapper doesn't seal properly, water continuously leaks into the bowl, causing the toilet to run.

To check the flapper, lift it up and inspect it for any signs of wear, such as cracks, corrosion, or build‑up of mineral deposits. If the flapper looks damaged, you'll need to replace it.

4. Replace the Flapper Valve

If the flapper is the problem, you can replace it with a new one. Flappers are inexpensive and easy to find at your local hardware store. Simply remove the old flapper by disconnecting the chain from the flush lever and detaching the flapper from the pegs on either side of the overflow tube.

Take the old flapper to the store to ensure you get the right size for your toilet model. Attach the new flapper in the same manner as the old one, making sure it creates a secure seal over the drain hole.

5. Check the Flush Valve Chain

The flush valve chain controls the flapper's movement when you press the toilet handle. If the chain is too long, it might get caught under the flapper, preventing it from closing properly. If it's too short, it might prevent the flapper from lifting fully during a flush.

To adjust the chain, unhook it from the flush lever and make the necessary adjustments so that there's just enough slack to allow the flapper to open and close freely. Reattach the chain to the flush lever when you're done.

6. Inspect the Fill Valve

If replacing the flapper doesn't solve the issue, the problem could lie with the fill valve. The fill valve controls the water level in the tank and shuts off the water once it reaches the proper level. If the valve is malfunctioning, the water may continue to flow into the tank, causing the toilet to run.

To check the fill valve, inspect the float that rises with the water level. If the float is set too high, it could be causing the water to overflow into the overflow tube. Adjust the height of the float by bending the arm or turning the screw on the fill valve to lower it.

7. Examine the Overflow Tube

The overflow tube is designed to direct excess water from the tank into the bowl if the fill valve fails to shut off. If the water is running into the overflow tube constantly, the water level in the tank may be too high. This can be fixed by adjusting the float or fill valve, as mentioned above.

If the overflow tube is cracked or damaged, it will need to be replaced.

8. Test the Toilet

After making the necessary adjustments or replacements, turn the water supply back on and let the tank fill. Once it's full, flush the toilet to make sure everything is working properly. Check the water level in the tank to ensure it's not too high and that the flapper is sealing correctly.

If the toilet still runs after completing these steps, there may be an issue with the flush valve or fill valve that requires professional attention. However, most running‑toilet problems can be resolved with these DIY fixes.

9. Monitor for Future Issues

Keep an eye on your toilet over the next few days to make sure the problem doesn't return. If you notice that it's still running intermittently, it might be time to replace the entire fill valve or flush valve assembly. Most hardware stores carry complete toilet repair kits that come with all the necessary parts.

Conclusion

A running toilet may seem like a minor inconvenience, but it can waste a significant amount of water and increase your water bills over time. By following these simple steps, you can fix the issue yourself and save money on repairs. Remember, the most common causes of a running toilet are a worn‑out flapper valve, a malfunctioning fill valve, or an improperly adjusted float. With a little time and effort, you can restore your toilet to full working order.