Common Causes of a Running Toilet and How to Fix Them

Modern wall-mounted white toilet in a small tiled bathroom with neutral and striped accents.

A running toilet isn’t just an inconvenience—it can waste a significant amount of water and inflate your water bill. 

This common plumbing issue often has simple solution and addressing it promptly can save water and prevent further damage. At Green Planet Plumbing, we’re here to help you identify the cause and guide you through the steps to fix it.

Why Is a Running Toilet a Problem?

  • Did you know a leaking toilet can waste 16,000 litres of water a year? Beyond the financial impact, it’s a huge strain on our water resources. Fixing this issue as soon as you notice it will save you money and help the environment.

Signs Your Toilet is Running

Before diving into solutions, confirm whether your toilet is running. Watch for these signs:

  • A constant sound of water running, even when the toilet isn’t in use.
  • Intermittent filling sounds, as though the toilet is refilling itself without being flushed.
  • A weak or delayed flush that requires holding the handle down longer.
  • Water leaking around the overflow pipe inside the tank.
  • Excessively long refill times after flushing.

If any of this sounds familiar, your toilet needs attention.

stylish bathroom with a white running toilet, pastel peach walls, wooden decor, green potted plants, and modern accessories on a light gray floor.

Common Causes of a Running Toilet

1. Worn-Out Flapper

The flapper is a rubber component that controls water flow from the tank to the bowl. Over time, it can wear out or become misaligned, causing water to leak continuously.

How to Fix It:

  • Turn off the water supply and flush the toilet to empty the tank.
  • Remove the old flapper and inspect for damage.
  • Replace it with a new one that fits your toilet model.

2. Improper Chain Length

The chain connecting the flush handle to the flapper can cause problems if it’s not adjusted properly. A chain that’s too short prevents the flapper from sealing, while one that’s too long can get tangled.

Solution:

  • Adjust the chain length to ensure it allows the flapper to open and close smoothly.
  • Test the flush to confirm the fix.

3. Fill Valve Issues

The fill valve refills the tank after each flush. If it’s faulty or clogged, it might cause water to overflow into the tank’s overflow tube, leading to continuous running.

Steps to Fix:

  • Shut off the water supply and drain the tank.
  • Replace the valve with a compatible model.
  • Refill the tank and test for leaks.

4. Float Misalignment

The float determines the water level in the tank. If it’s set too high, water will spill into the overflow tube, creating a constant flow.

Fix It:

  • Adjust the float height using the attached screw or clip.
  • Ensure the water level stays slightly below the overflow tube.

5. Sediment Build-Up

Sediment from hard water can accumulate in your toilet’s internal parts, particularly the fill valve. This can block proper functioning and cause leaks.

How to Address It:

  • Clean the tank components with a vinegar solution.
  • If cleaning doesn’t solve the issue, replace the affected parts.
Professional plumber in blue overalls using a plunger to unclog a toilet in a modern bathroom, with a toolbox and cleaning tools nearby.

Preventative Measures

Regular maintenance can help prevent a running toilet:

  • Periodically inspect and clean internal components.
  • Avoid using harsh chemical cleaners in the tank.
  • Replace parts showing signs of wear before they fail completely.

When to Call a Plumber

Some running toilet issues require expert attention.

If these DIY steps don’t resolve the issue, or if you’re unsure about performing the repairs, it’s best to contact a licensed plumber. They can quickly diagnose and fix complex problems, ensuring your toilet runs efficiently.

Green Planet Plumbing can help, our team specialises in water-efficient plumbing solutions and will ensure your toilet is working perfectly.

General Plumbing Repairs

Fixing a running toilet is a manageable task for most homeowners. By addressing the issue promptly, you’ll save water, reduce your bills, and restore peace to your home. contact the professionals at Green Planet Plumbing. With our eco-friendly approach and reliable service, we’ll get your toilet running efficiently in no time.Visit Green Planet Plumbing or call us on 02 4911 9402 today for fast, professional service.