How-To Guides · DIY & home
How to Fix a Running Toilet (Easy DIY)
A toilet that keeps running isn't just annoying. Leaks like this can waste thousands of gallons of water a month. The good news, it's usually a cheap, easy fix. Here's how to find the problem and fix it.
1. How The Tank Works
First, lift the tank lid and look inside. When you flush, the handle pulls a chain that lifts a rubber flap at the bottom, called the flapper. Water rushes into the bowl. Then the fill valve refills the tank, and a float rises with the water and shuts the valve off.
2. Why It Keeps Running
A running toilet almost always means one of two things. Either the flapper isn't sealing, so water leaks into the bowl, or the water level is set too high, so it spills into the tall overflow tube in the middle.
3. Test 1: The Food Coloring Test
To check the flapper, put a few drops of food coloring in the tank. Don't flush. Wait at least fifteen minutes. If color shows up in the bowl, the flapper is leaking.
4. Fix 1: The Chain
Start with the easiest fix, the chain. If it's too short, it holds the flapper open. If it's too long, it can get stuck underneath it. You want just a little slack, about half an inch.
5. Fix 2: Replace The Flapper
If the flapper still leaks, replace it. Turn the shutoff valve behind the toilet clockwise to close it, and flush to empty the tank. Unhook the old flapper, and take it to the store so you can match it. Snap the new one on, hook up the chain, and turn the water back on.
6. Fix 3: Lower The Water Level
If water is pouring into the overflow tube, the water level is too high. It should stop about half an inch to one inch below the top of that tube. Lower the float. On most newer toilets, squeeze the clip and slide the float down. On older ones with a ball on an arm, turn the adjustment screw.
7. Still Running?
Still running? Gently lift the float while it's filling. If the water stops, the float just needs adjusting. If it keeps running anyway, the fill valve is worn out and needs to be replaced. Fill valve kits are sold at any hardware store, or a plumber can do it quickly.
Tools that make this easier
Simple Google Sheets + Excel tools from WiscHaven. Buy once, no subscription.
Sources
- portland.gov/water/water-efficiency-programs/fixatoiletleak
- supplyhouse.com/how-to-fix-a-running-toilet
Checked against the official sources above. Steps can change as apps update - tell us if something looks different: wischavenindustries@gmail.com