Why Is Your Toilet Running?

A running toilet is more than just an annoying noise; it is a major source of water waste that can add hundreds of dollars to your annual utility bill. Most running toilets are caused by a few common mechanical failures within the tank. Understanding the anatomy of your toilet tank is the first step toward a DIY fix. The main components involved are the fill valve, the flapper, the overflow tube, and the flush handle linkage.

Step-by-Step Instructions to Fix a Running Toilet

Before you begin any repairs, turn off the water supply valve located behind the toilet. Flush the toilet to empty the tank of water. This allows you to inspect the parts without a mess.

1. Inspect the Flapper: The most common culprit is a worn-out rubber flapper. If the flapper doesn’t seal tightly against the flush valve seat, water leaks into the bowl. Clean the rim of the seal or replace the flapper if the rubber feels brittle or slimy.

2. Adjust the Water Level: If water is constantly flowing into the overflow tube, your fill valve is set too high. Adjust the float (either a ball on a rod or a sliding cylinder) so that the water level sits about an inch below the top of the overflow tube.

3. Check the Fill Valve: If adjusting the float doesn’t stop the flow, the fill valve may be defective. These are inexpensive and can be replaced by unscrewing the locknut at the bottom of the tank and installing a universal fill valve kit.

Frequently Asked Questions