Water Damage and Your Toilet: A Guide to Fixing a Running Toilet

By | September 22, 2025

Water Damage and Your Toilet: A Guide to Fixing a Running Toilet

A running toilet can be a frustrating and costly problem, wasting hundreds of gallons of water per day and increasing your water bill significantly. However, beyond the financial implications, a continuously running toilet can also lead to water damage, which can be devastating to your home and your belongings. In this article, we will explore the causes of a running toilet, the potential water damage it can cause, and provide a step-by-step guide on how to fix the issue.

Causes of a Running Toilet

A running toilet is typically caused by a faulty flapper or fill valve. The flapper is the rubber valve that covers the hole at the bottom of the tank, and the fill valve is the mechanism that refills the tank with water after each flush. If either of these components is not functioning properly, water will continue to flow into the toilet bowl, causing the toilet to run constantly.

Other common causes of a running toilet include:

  • A misaligned or loose flapper chain
  • A clogged or dirty flapper
  • A faulty or worn-out fill valve
  • A cracked or damaged toilet tank

Water Damage Caused by a Running Toilet

A running toilet can cause significant water damage to your home, including:

  • Floor damage: Water can seep into the floor and damage the subfloor, flooring, and surrounding structures.
  • Wall damage: Water can also seep into the walls, causing damage to the drywall, paint, and wallpaper.
  • Ceiling damage: If the toilet is located on an upper floor, water can seep into the ceiling, causing damage to the drywall, paint, and ceiling tiles.
  • Mold and mildew growth: Excess moisture can lead to the growth of mold and mildew, which can be hazardous to your health and require costly remediation.

Fixing a Running Toilet: A Step-by-Step Guide

Fixing a running toilet is a relatively simple process that can be completed with a few basic tools. Here’s a step-by-step guide to help you fix the issue:

  1. Turn off the water supply: Locate the shut-off valve behind the toilet and turn it clockwise to shut off the water supply to the toilet.
  2. Drain the tank: Flush the toilet to drain the tank, and then use a sponge or cup to remove any remaining water.
  3. Inspect the flapper: Check the flapper for any signs of wear or damage. If it’s damaged, replace it with a new one.
  4. Adjust the flapper chain: If the flapper chain is loose or misaligned, adjust it to ensure it’s properly connected to the flapper.
  5. Check the fill valve: Inspect the fill valve for any signs of wear or damage. If it’s damaged, replace it with a new one.
  6. Test the toilet: Once you’ve made the necessary repairs, turn the water supply back on and test the toilet to ensure it’s no longer running.

Preventative Measures

To prevent a running toilet from causing water damage in the future, consider the following preventative measures:

  • Regularly inspect the toilet: Check the toilet regularly for any signs of wear or damage, and make repairs as needed.
  • Replace the flapper and fill valve: Replace the flapper and fill valve every 5-7 years to ensure they’re functioning properly.
  • Install a toilet with a low-flow design: Installing a toilet with a low-flow design can help reduce water waste and prevent water damage.

Conclusion

A running toilet can be a costly and frustrating problem, but it’s also a preventable one. By understanding the causes of a running toilet and taking the necessary steps to fix the issue, you can prevent water damage and save money on your water bill. Remember to regularly inspect your toilet and make repairs as needed to ensure it’s functioning properly. If you’re not comfortable making the repairs yourself, consider hiring a professional plumber to fix the issue.