June 7, 2024

How to Stop a Toilet from Running


A running toilet can be a frustrating and costly issue. Not only does it raise your water bill by continually wasting water, but it can also cause potential damage if left unchecked. Don’t let your money and your water trickle away, diagnose the reason your toilet is running and fix the problem today

Fortunately, many common toilet issues can be easily resolved. To help, we’ve created this handy guide, along with the video below, so that you can identify and fix the most common causes of a running toilet. If you decide to call in a professional plumber instead of tackling the fix yourself, Applewood’s licensed experts are on call seven days a week.

5 Reasons Your Toilet Won’t Stop Running

1. Faulty Flapper

A worn out toilet flapper.

A common culprit for a running toilet is a faulty flapper. The flapper is the rubber valve that covers the opening at the bottom of the toilet tank. When you flush, it lifts to release water into the bowl, then closes to seal the tank for refilling. Over time, the flapper can become worn, warped or cracked to the point that it no longer creates a watertight seal. This can lead to water continuously leaking from the tank into the bowl.  

The fix: Turn off the water supply to the toilet, flush to empty the tank, and inspect the flapper. If it’s cracked, brittle or has mineral build-up, replace it with a new one from your local hardware store. Bring the old flapper with you to make sure you get the right size to match your toilet model.

2. Flapper Chain Length

Sometimes, the issue isn’t the flapper itself, but the chain that connects it to the flush lever. If the chain is too short or too long, it may prevent the flapper from functioning properly or closing fully.

The fix: Adjust the chain length so it has enough slack to allow the flapper to seal completely (but not so much that it gets tangled or caught). Simply unhook the chain and reattach it to a different link to shorten or lengthen it.

3. Float or Float Ball Level

A newly installed toilet float ball.

The float (or float ball in older toilet models) rises with the water level in the tank and shuts off the water when it reaches a set height. If not properly calibrated, the float ball allows the water to fill too high, spilling into the overflow tube.

The fix: In older toilets, bend the float arm downward to lower the water level. In newer models, find the adjustment screw or clip that controls the float’s height. Adjust the float so that it sits about 1 inch below the top of the overflow tube when the tank is full. If your float is leaking or damaged, replace it with a new one from your hardware store.

4. Overactive Fill Valve

Above view of a toilet tank interior.

The fill valve is responsible for refilling the toilet tank with water after each flush. If the fill valve is faulty or set too high, it can cause the water to continuously run into the overflow tube.

The fix: Check the fill valve for any debris or mineral buildup and clean it if necessary. Adjust the fill valve height by turning the adjustment screw or clip so that the water level in the tank stops about 1 inch below the top of the overflow tube. If adjusting doesn’t help, consider replacing the fill valve.

5. Leaky Flush Valve

The flush valve is the channel between the toilet tank and the toilet bowl. It’s the opening that the flapper sits on. If the flush valve or its gasket is damaged, water will leak from the tank into the bowl continuously.

The fix: Inspect the flush valve for any cracks, warping, or mineral buildup. Replacing a flush valve is more complicated, and this might be a good time to call a professional. However, if you’re comfortable, you can purchase a replacement kit at your local hardware store and follow the manufacturer’s instructions.

Why Does My Toilet Keep Running?

If you’ve tried the steps above and your toilet still runs constantly, it may be time to call a pro. Applewood’s friendly and punctual plumbers are on-hand from 6:00AM to 10:00PM every day of the week so you don’t have to listen to that running toilet any longer. Schedule your service now.

Call  303-328-3060

Schedule Now