Why Does My Toilet Keep Running?

A toilet that keeps running may seem like a minor annoyance, but it can waste hundreds of gallons of water per day and significantly increase your water bill. In most cases, a running toilet points to a worn or misaligned internal part, and the longer it’s ignored, the worse the problem can become.

Let’s break down what causes a toilet to run continuously and when professional help is the best option.

1. Worn or Damaged Flapper Valve

The flapper is the rubber seal at the bottom of the toilet tank that controls water flow into the bowl.

What happens when it fails:

• Water leaks from the tank into the bowl

• The tank keeps refilling nonstop

• You may hear a constant trickling sound

Common causes:

• Rubber deterioration over time

• Improper flapper size

• Mineral buildup is preventing a tight seal

Fix:

Replacing the flapper is often a quick and affordable solution.

2. Float Is Set Too High

The float controls how much water fills the tank.

When it’s too high:

• Water flows into the overflow tube

• The toilet keeps refilling

• You may hear water running after each flush

Solution:

Adjusting the float height usually restores proper operation.

3. Faulty Fill Valve

The fill valve refills the tank after flushing. If it’s damaged or worn, it may not shut off properly.

Signs of a bad fill valve:

• Constant hissing sound

• Tank refills slowly or never stops

• Inconsistent water levels

Fix:

Replacing the fill valve is often the most effective repair.

4. Cracked or Misaligned Overflow Tube

The overflow tube prevents flooding by directing excess water into the bowl.

If it’s damaged or misaligned:

• Water continuously drains into the bowl

• The tank never reaches the shut-off level

Solution:

A plumber can inspect and replace damaged components if needed.

5. Chain Issues Inside the Tank

The chain connects the flush handle to the flapper.

Problems occur when:

• The chain is too short and holds the flapper open

• The chain gets tangled

• The flapper doesn’t fully close

Fix:

Adjusting or replacing the chain usually resolves the issue.

When Should You Call a Plumber?

You should contact a professional plumber if:

• The toilet keeps running after basic adjustments

• You notice water pooling around the base

• Internal parts are corroded or broken

• Multiple toilets have the same issue

• You want to avoid trial-and-error repairs

A licensed plumber can diagnose the issue quickly and prevent unnecessary water waste.

How a Plumber Can Fix a Running Toilet

Professional toilet repair services may include:

• Full tank component inspection

• Flapper, fill valve, or float replacement

• Toilet rebuilds for older units

• Leak detection and water efficiency upgrades

A constantly running toilet isn’t just noisy, it’s a sign of internal wear that can lead to higher water bills and hidden leaks. While some fixes are simple, persistent problems should always be handled by a professional to ensure long-term reliability.

If your toilet won’t stop running, calling a licensed plumber can save water, money, and future headaches.

Call Vertical Plumbing at (480) 577-8720