A running toilet might seem like a minor inconvenience, but it can waste hundreds of gallons of water per day, resulting in a spike in your water bill and unnecessary strain on your plumbing. The good news? Most running toilet issues can be fixed quickly with basic tools and minimal plumbing knowledge.
In this DIY guide, we’ll walk you through the common causes of a running toilet and the simple steps to repair it, saving you money, water, and the hassle of calling in a plumber.
Why Is Your Toilet Running?
Before diving into repairs, it’s important to understand what’s causing the issue. A running toilet typically means water is continuously flowing from the tank to the bowl, even when it hasn’t been flushed.
Most common causes:
- Faulty flapper valve
- Malfunctioning fill valve
- Improper float level
- Leaky flush handle chain
Each of these components is inexpensive and can be replaced or adjusted in just a few minutes.
Tools You’ll Need:
- Adjustable wrench
- Screwdriver
- Replacement toilet flapper or fill valve (if needed)
- Clean cloth or sponge
- A bucket or a small container
Step-by-Step: How to Fix a Running Toilet
1. Turn Off the Water Supply
Locate the shut-off valve behind the toilet and turn it clockwise until it stops. Flush the toilet to empty the tank and bowl. This gives you a dry working area.
2. Check the Flapper
The flapper is a rubber seal at the bottom of the tank. It lifts when you flush and closes afterward to stop the flow of water.
Signs your flapper is the problem:
- It’s warped, cracked, or doesn’t sit properly on the valve seat
- It doesn’t seal completely, causing water to leak into the bowl
How to fix:
- Unhook the flapper from the overflow tube
- Install a new flapper of the same size and shape
- Reattach the chain to the flush handle arm with slight slack
Tip: If the chain is too short or too long, it can cause the flapper to malfunction.
3. Adjust the Float Height
If the float is too high, the tank overfills and causes the water to spill into the overflow tube, resulting in continuous running.
For float cup-style fill valves:
- Pinch the clip on the side of the float
- Slide the float down to lower the water level
For ball float systems:
- Adjust the screw on top of the fill valve to lower the arm
Target water level: About 1 inch below the top of the overflow tube.
4. Inspect the Fill Valve
If the water continues to run after adjusting the flapper and float, the fill valve may be defective.
How to replace the fill valve:
- Disconnect the water supply line using an adjustable wrench
- Remove the old fill valve by unscrewing the locknut
- Insert the new valve and tighten the nut
- Connect the refill tube and adjust float height as needed
- Turn the water back on and test
Most modern fill valves are universal and come with easy-to-follow instructions.
5. Check the Handle and Chain
Sometimes, the flush handle or chain can get stuck, preventing the flapper from sealing.
- Ensure the handle moves freely and isn’t sticking
- Make sure the chain isn’t tangled or caught under the flapper
If the handle is corroded or broken, replace it with a new one from your local hardware store.
Test Your Fix
Once you’ve made the necessary adjustments:
- Turn the water supply back on
- Let the tank refill
- Listen for any continuous water flow
- Drop food coloring into the tank (optional). If it seeps into the bowl without flushing, there’s still a leak
If no water runs after flushing and refilling, your toilet is fixed!
How Much Can You Save?
A running toilet can waste up to 200 gallons of water per day. At current water rates, that could cost an extra $60–$100 per month on your utility bill.
By spending less than $20 on parts and 30 minutes of your time, you can:
- Conserve water
- Avoid expensive plumbing visits
- Lower your environmental footprint
- Extend the life of your toilet
When to Call a Plumber
While most toilet issues can be fixed DIY-style, you should call a professional if:
- Your toilet is leaking at the base
- There are cracks in the tank or bowl
- You hear gurgling or see backflow from drains
- Your fixes don’t stop the running water
Final Thoughts
Fixing a running toilet is one of the easiest and most cost-effective home repairs. With just a few tools and a little patience, you can restore proper function, conserve water, and prevent high utility bills.
By understanding your toilet’s basic mechanics and knowing what to look for, you can tackle common plumbing issues confidently and keep your bathroom running smoothly all year long. Contact us today!